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How long for a plug to color?
How long for a plug to color?
I finally got around to starting the break-in on my CR125 yesterday.
Everybody says that the bikes are brutally rich down low as delivered
- and basically won't even run, fouling plugs in 5 minutes if riding
in technical terrain. The JD jetting kit uses a 35 pilot, down from
55 stock (!) and keeps the stock main, with his special secret
needle. I expected to have a bunch of trouble with the stock jets, so
I pre-emptively dropped the needle clip a position and lowered the
float 1.5mm. I also set the air screw to 3 turns out.
The first heat cycle consisted of 3-5 minutes of idling, with the
occasional blip to keep it running. It was definately rich off idle,
although it wasn't blubbering excessively, and it loaded up a couple
of times (now I know what "loading up" means) - I thought I was
fouling a plug once, but it cleared by holding mid-throttle for a few
seconds "blooooooooooorraaaAAAPPPPP" accompanied with 25000 cu ft. of
smoke once it wound up. The smoking cleared right up after a few
seconds.
After the first heat cycle, I pulled the plug and it was basically
white - maybe a little grayish down deep on the insulator. Given the
rich condition, I expected that it would've been well sooted up by
then. What gives?
JayC
I finally got around to starting the break-in on my CR125 yesterday.
Everybody says that the bikes are brutally rich down low as delivered
- and basically won't even run, fouling plugs in 5 minutes if riding
in technical terrain. The JD jetting kit uses a 35 pilot, down from
55 stock (!) and keeps the stock main, with his special secret
needle. I expected to have a bunch of trouble with the stock jets, so
I pre-emptively dropped the needle clip a position and lowered the
float 1.5mm. I also set the air screw to 3 turns out.
The first heat cycle consisted of 3-5 minutes of idling, with the
occasional blip to keep it running. It was definately rich off idle,
although it wasn't blubbering excessively, and it loaded up a couple
of times (now I know what "loading up" means) - I thought I was
fouling a plug once, but it cleared by holding mid-throttle for a few
seconds "blooooooooooorraaaAAAPPPPP" accompanied with 25000 cu ft. of
smoke once it wound up. The smoking cleared right up after a few
seconds.
After the first heat cycle, I pulled the plug and it was basically
white - maybe a little grayish down deep on the insulator. Given the
rich condition, I expected that it would've been well sooted up by
then. What gives?
JayC
Re: How long for a plug to color?
On May 19, 4:55 pm, JayC <j...@sysmatrix,net > wrote:
> After the first heat cycle, I pulled the plug and it was basically
> white - maybe a little grayish down deep on the insulator. Given the
> rich condition, I expected that it would've been well sooted up by
> then. What gives?
>
> JayC
Jay,
I am no jetting expert - far from that - but be careful with gasoline
blended with alcohol. The plug color will always show leaner than it
really is, I mean, when ok it will show white-ish instead of tan. I
suggest that you go more by feel than by plug color. Also remember
that ethanol has less energy than gasoline and will require a richer
jetting. To compensate, you can go higher compression and get more
power, but it will always consume more fuel.
ymmv
-- Tiago
25% pure cane sugar ethanol added to my gasoline.
On May 19, 4:55 pm, JayC <j...@sysmatrix,net > wrote:
> After the first heat cycle, I pulled the plug and it was basically
> white - maybe a little grayish down deep on the insulator. Given the
> rich condition, I expected that it would've been well sooted up by
> then. What gives?
>
> JayC
Jay,
I am no jetting expert - far from that - but be careful with gasoline
blended with alcohol. The plug color will always show leaner than it
really is, I mean, when ok it will show white-ish instead of tan. I
suggest that you go more by feel than by plug color. Also remember
that ethanol has less energy than gasoline and will require a richer
jetting. To compensate, you can go higher compression and get more
power, but it will always consume more fuel.
ymmv
-- Tiago
25% pure cane sugar ethanol added to my gasoline.
Re: How long for a plug to color?
> I am no jetting expert - far from that - but be careful with gasoline
> blended with alcohol. The plug color will always show leaner than it
> really is, I mean, when ok it will show white-ish instead of tan. I
> suggest that you go more by feel than by plug color. Also remember
> that ethanol has less energy than gasoline and will require a richer
> jetting. To compensate, you can go higher compression and get more
> power, but it will always consume more fuel.
I am aware of all of the above. I have verified that jetting has to
be richened up across the board due to the 10% ethanol - I've had to
richen up all of the 4-strokes already. I also am no plug reader -
which is why I'm asking the titled question ;).
Thanks for the reply.
JayC
> I am no jetting expert - far from that - but be careful with gasoline
> blended with alcohol. The plug color will always show leaner than it
> really is, I mean, when ok it will show white-ish instead of tan. I
> suggest that you go more by feel than by plug color. Also remember
> that ethanol has less energy than gasoline and will require a richer
> jetting. To compensate, you can go higher compression and get more
> power, but it will always consume more fuel.
I am aware of all of the above. I have verified that jetting has to
be richened up across the board due to the 10% ethanol - I've had to
richen up all of the 4-strokes already. I also am no plug reader -
which is why I'm asking the titled question ;).
Thanks for the reply.
JayC
Re: How long for a plug to color?
If you have a few minutes to read something. Try this
from Gordon Jennings. How to read a spark plug.
http :// www .strappe,com /plugs.html
Might be old news to some of the folks here.
Interesting to me for sure.
SloCalSpode
----------------------------------------------------------------------------
JayC wrote:
> Thanks for the reply.
> JayC
If you have a few minutes to read something. Try this
from Gordon Jennings. How to read a spark plug.
http :// www .strappe,com /plugs.html
Might be old news to some of the folks here.
Interesting to me for sure.
SloCalSpode
----------------------------------------------------------------------------
JayC wrote:
> Thanks for the reply.
> JayC
Re: How long for a plug to color?
On Mon, 19 May 2008 12:55:27 -0700 (PDT), JayC <jwc@sysmatrix,net > wrote:
>I finally got around to starting the break-in on my CR125 yesterday.
>Everybody says that the bikes are brutally rich down low as delivered
>- and basically won't even run, fouling plugs in 5 minutes if riding
>in technical terrain. The JD jetting kit uses a 35 pilot, down from
>55 stock (!) and keeps the stock main, with his special secret
>needle. I expected to have a bunch of trouble with the stock jets, so
>I pre-emptively dropped the needle clip a position and lowered the
>float 1.5mm. I also set the air screw to 3 turns out.
>
>The first heat cycle consisted of 3-5 minutes of idling, with the
>occasional blip to keep it running. It was definately rich off idle,
>although it wasn't blubbering excessively, and it loaded up a couple
>of times (now I know what "loading up" means) - I thought I was
>fouling a plug once, but it cleared by holding mid-throttle for a few
>seconds "blooooooooooorraaaAAAPPPPP" accompanied with 25000 cu ft. of
>smoke once it wound up. The smoking cleared right up after a few
>seconds.
what color smoke?
>
>After the first heat cycle, I pulled the plug and it was basically
>white - maybe a little grayish down deep on the insulator. Given the
>rich condition, I expected that it would've been well sooted up by
>then. What gives?
>
>JayC
I've been reading plugs a lot recently... in groups of 4... though I'll
lead with a caveat that I haven't done anything with two strokes. I think
there is a bit of nuance around reading plugs and that you are wise to
gather other kinds of data, like also reading the inside of the exhaust
headers, sound, vacuum, head temperature, etc. At least I'm finding data
SETS carve up solution space more neatly and confidently than single data
points.
I've been getting significant color changes in 15-20 minutes of
running/riding. I operate under the belief system (again, it appears there
are several) that the pertinence of a particular region of the insulator
varies with average engine speed, with the low-speed/idle area near the tip
and the high-speed area near the base where the insulator is coolest. As
you increase engine power, the additional heat burns away the coloring at
the tip and possibly at the mid-point... you have to look at the base.
It sounds like your plug would be reading fine (a little gray oriented
toward the base of the insulator), IF you had been up at higher
power/rpm... but you're burning the shit off the tip-end of the insulator
without going higher speed. I think you're running lean. Your bike setup
might not have been done with gasohol in mind... it runs you effectively
lean and therefor hotter (white plug coloring). I run lower fuel to oil
ratios in all my 2-stroke lawn equipment because of this... say moving 40:1
to 32:1, etc). It is my understanding too that most engines are delivered
at the lean end of the spectrum for EPA testing. Maybe not an issue for
this bike, but maybe. Also, you're messing around only with the pilot jet
and while it contributes fuel across the full throttle band, it'll have the
greatest impact at more closed throttles. That's a huge drop. The plug is
white in the low-rpm/power area. These go together. Did you try to read the
plug before you broke it in? Actually, do you want to be doing break-in
before or after you set the bike up? I'd think it matters but I don't know
the answer to that.
A cheap experiment I might suggest would be to get an IR thermometer and
run the engine with the stock setup at a constant rpm for whatever time it
takes to reach operating temp. See what the head temp is... be precise in
where you aim it and try to pick an area where the material is "consistent"
as different materials and colors and finishes will have different levels
of heat emission. Then set it up your way... which was hotter? If the
latter was *markedly* hotter 50-100 degrees, I'd think you have a serious
lean condition.
You can verify your plug reading by looking inside the exhaust header...
black = rich, white=lean. Look for dark tan/gray here too.
Since you're running a white on the insulator near the tip, you have heat
and maybe that's coming from ignition advance. Look at the ground electrode
and see if you can see a "heat line" on it between the elbow and the plug
base. If so, you're probably in the ball park. If not, you might be running
too much advance and getting extra heat from that.
Then again, I can't get my shit working so I'd ignore everything I just
said. Good luck.
Mike
--
Mike W.
96 XR400
70 CT70
71 KG 100 (Hodaka-powered)
99 KZ1000P (training)
99 KZ1000P (rider)
00 Beta Rev-3
On Mon, 19 May 2008 12:55:27 -0700 (PDT), JayC <jwc@sysmatrix,net > wrote:
>I finally got around to starting the break-in on my CR125 yesterday.
>Everybody says that the bikes are brutally rich down low as delivered
>- and basically won't even run, fouling plugs in 5 minutes if riding
>in technical terrain. The JD jetting kit uses a 35 pilot, down from
>55 stock (!) and keeps the stock main, with his special secret
>needle. I expected to have a bunch of trouble with the stock jets, so
>I pre-emptively dropped the needle clip a position and lowered the
>float 1.5mm. I also set the air screw to 3 turns out.
>
>The first heat cycle consisted of 3-5 minutes of idling, with the
>occasional blip to keep it running. It was definately rich off idle,
>although it wasn't blubbering excessively, and it loaded up a couple
>of times (now I know what "loading up" means) - I thought I was
>fouling a plug once, but it cleared by holding mid-throttle for a few
>seconds "blooooooooooorraaaAAAPPPPP" accompanied with 25000 cu ft. of
>smoke once it wound up. The smoking cleared right up after a few
>seconds.
what color smoke?
>
>After the first heat cycle, I pulled the plug and it was basically
>white - maybe a little grayish down deep on the insulator. Given the
>rich condition, I expected that it would've been well sooted up by
>then. What gives?
>
>JayC
I've been reading plugs a lot recently... in groups of 4... though I'll
lead with a caveat that I haven't done anything with two strokes. I think
there is a bit of nuance around reading plugs and that you are wise to
gather other kinds of data, like also reading the inside of the exhaust
headers, sound, vacuum, head temperature, etc. At least I'm finding data
SETS carve up solution space more neatly and confidently than single data
points.
I've been getting significant color changes in 15-20 minutes of
running/riding. I operate under the belief system (again, it appears there
are several) that the pertinence of a particular region of the insulator
varies with average engine speed, with the low-speed/idle area near the tip
and the high-speed area near the base where the insulator is coolest. As
you increase engine power, the additional heat burns away the coloring at
the tip and possibly at the mid-point... you have to look at the base.
It sounds like your plug would be reading fine (a little gray oriented
toward the base of the insulator), IF you had been up at higher
power/rpm... but you're burning the shit off the tip-end of the insulator
without going higher speed. I think you're running lean. Your bike setup
might not have been done with gasohol in mind... it runs you effectively
lean and therefor hotter (white plug coloring). I run lower fuel to oil
ratios in all my 2-stroke lawn equipment because of this... say moving 40:1
to 32:1, etc). It is my understanding too that most engines are delivered
at the lean end of the spectrum for EPA testing. Maybe not an issue for
this bike, but maybe. Also, you're messing around only with the pilot jet
and while it contributes fuel across the full throttle band, it'll have the
greatest impact at more closed throttles. That's a huge drop. The plug is
white in the low-rpm/power area. These go together. Did you try to read the
plug before you broke it in? Actually, do you want to be doing break-in
before or after you set the bike up? I'd think it matters but I don't know
the answer to that.
A cheap experiment I might suggest would be to get an IR thermometer and
run the engine with the stock setup at a constant rpm for whatever time it
takes to reach operating temp. See what the head temp is... be precise in
where you aim it and try to pick an area where the material is "consistent"
as different materials and colors and finishes will have different levels
of heat emission. Then set it up your way... which was hotter? If the
latter was *markedly* hotter 50-100 degrees, I'd think you have a serious
lean condition.
You can verify your plug reading by looking inside the exhaust header...
black = rich, white=lean. Look for dark tan/gray here too.
Since you're running a white on the insulator near the tip, you have heat
and maybe that's coming from ignition advance. Look at the ground electrode
and see if you can see a "heat line" on it between the elbow and the plug
base. If so, you're probably in the ball park. If not, you might be running
too much advance and getting extra heat from that.
Then again, I can't get my shit working so I'd ignore everything I just
said. Good luck.
Mike
--
Mike W.
96 XR400
70 CT70
71 KG 100 (Hodaka-powered)
99 KZ1000P (training)
99 KZ1000P (rider)
00 Beta Rev-3
Re: How long for a plug to color?
On Tue, 20 May 2008 22:03:36 -0400, Mike W. <outofthe@emailbiz,com > wrote:
>Did you try to read the
>plug before you broke it in?
Meant to read... did you try to read the plug before you converted the
carb?
M
--
Mike W.
96 XR400
70 CT70
71 KG 100 (Hodaka-powered)
99 KZ1000P (training)
99 KZ1000P (rider)
00 Beta Rev-3
On Tue, 20 May 2008 22:03:36 -0400, Mike W. <outofthe@emailbiz,com > wrote:
>Did you try to read the
>plug before you broke it in?
Meant to read... did you try to read the plug before you converted the
carb?
M
--
Mike W.
96 XR400
70 CT70
71 KG 100 (Hodaka-powered)
99 KZ1000P (training)
99 KZ1000P (rider)
00 Beta Rev-3
Re: How long for a plug to color?
On Tue, 20 May 2008 22:03:36 -0400, Mike W. <outofthe@emailbiz,com > wrote:
> I expected to have a bunch of trouble with the stock jets, so
>>I pre-emptively dropped the needle clip a position and lowered the
>>float 1.5mm. I also set the air screw to 3 turns out.
Damn you! I was sitting out next to my future ex-KZP and thought I
remembered this. So you also took steps to make the engine run leaner with
the needle position and the fuel level. I'm not sure if you're following a
time-tested known-good setup or just making the changes on an impulse. If
the latter, follow best practices... change one thing at a time. Gordon
(whose birthday is today) wrote an extremely well-researched piece right
after he wrote the "Gordon mods" for the XR400 on how to do this sort of
thing in the general case. This has got to be 10 years ago now but it
should be findable. If it wasn't on RMD, it was on the XR400 list and I
*think* someplace out on the family server I have like the first 2 years of
posts for that group if you can't find it. It's simple though... if you're
not following someone else's validated setup, take simple steps with binary
results.... this improved/worsened things... advance. One caveat if I
recall it... there was a little bit of ambiguity between float height and
float limit in the initial writing. He obviously understood the difference
but the wording made it a challenge in a few places to understand which he
was referencing. Good luck.
Mike
--
Mike W.
96 XR400
70 CT70
71 KG 100 (Hodaka-powered)
99 KZ1000P (training)
99 KZ1000P (rider)
00 Beta Rev-3
On Tue, 20 May 2008 22:03:36 -0400, Mike W. <outofthe@emailbiz,com > wrote:
> I expected to have a bunch of trouble with the stock jets, so
>>I pre-emptively dropped the needle clip a position and lowered the
>>float 1.5mm. I also set the air screw to 3 turns out.
Damn you! I was sitting out next to my future ex-KZP and thought I
remembered this. So you also took steps to make the engine run leaner with
the needle position and the fuel level. I'm not sure if you're following a
time-tested known-good setup or just making the changes on an impulse. If
the latter, follow best practices... change one thing at a time. Gordon
(whose birthday is today) wrote an extremely well-researched piece right
after he wrote the "Gordon mods" for the XR400 on how to do this sort of
thing in the general case. This has got to be 10 years ago now but it
should be findable. If it wasn't on RMD, it was on the XR400 list and I
*think* someplace out on the family server I have like the first 2 years of
posts for that group if you can't find it. It's simple though... if you're
not following someone else's validated setup, take simple steps with binary
results.... this improved/worsened things... advance. One caveat if I
recall it... there was a little bit of ambiguity between float height and
float limit in the initial writing. He obviously understood the difference
but the wording made it a challenge in a few places to understand which he
was referencing. Good luck.
Mike
--
Mike W.
96 XR400
70 CT70
71 KG 100 (Hodaka-powered)
99 KZ1000P (training)
99 KZ1000P (rider)
00 Beta Rev-3
Re: How long for a plug to color?
OK - nobody is listening, so I'll start over.
I'm not reading a plug, and not adjusting jetting at the moment. A
slew of people that bought these '06 leftovers have been battling with
fouling plugs - the out of the box setup is very rich on the bottom.
My bike is rich on the bottom, that's a given - the loading up and
subsequent smoke screen was ample evidence of that. And yes, ethanol
makes the stock main lean, but that is neither here nor there.
After running at or close to idle for 3-5 minutes, with a rich
condition, I pulled the plug just to see what it look like. I was
expecting that it would be black, but it was close to white.
Personally, I've never seen a brand-new plug change colors in short
order, although I've never done plug readings to set up jetting.
Common plug-jetting wisdom states to put in a brand-new plug and do a
20 second run then throttle-chop (for the main anyway). My question
is simply, does this REALLY give a color that corresponds to mixture?
If so, what could cause a blatantly rich running engine to produce a
plug that is white after 3-5 minutes?
JayC
OK - nobody is listening, so I'll start over.
I'm not reading a plug, and not adjusting jetting at the moment. A
slew of people that bought these '06 leftovers have been battling with
fouling plugs - the out of the box setup is very rich on the bottom.
My bike is rich on the bottom, that's a given - the loading up and
subsequent smoke screen was ample evidence of that. And yes, ethanol
makes the stock main lean, but that is neither here nor there.
After running at or close to idle for 3-5 minutes, with a rich
condition, I pulled the plug just to see what it look like. I was
expecting that it would be black, but it was close to white.
Personally, I've never seen a brand-new plug change colors in short
order, although I've never done plug readings to set up jetting.
Common plug-jetting wisdom states to put in a brand-new plug and do a
20 second run then throttle-chop (for the main anyway). My question
is simply, does this REALLY give a color that corresponds to mixture?
If so, what could cause a blatantly rich running engine to produce a
plug that is white after 3-5 minutes?
JayC
Re: How long for a plug to color?
On Tue, 20 May 2008 21:09:16 -0700 (PDT), JayC <jwc@sysmatrix,net > wrote:
>OK - nobody is listening, so I'll start over.
Actually, I was. I gave you the best data I could toward your question...
I've seen plugs change in 15-20 min. I don't have anything quicker than
that.
I know you have some data from the internet, but what you describe as for
symptoms... in the context of the changes you made and the conditions under
which you read the plug... leads me to believe you went too far and
followed a process that is something other than best-practice-grade for
tuning your bike. Good luck.
--
Mike W.
96 XR400
70 CT70
71 KG 100 (Hodaka-powered)
99 KZ1000P (training)
99 KZ1000P (rider)
00 Beta Rev-3
On Tue, 20 May 2008 21:09:16 -0700 (PDT), JayC <jwc@sysmatrix,net > wrote:
>OK - nobody is listening, so I'll start over.
Actually, I was. I gave you the best data I could toward your question...
I've seen plugs change in 15-20 min. I don't have anything quicker than
that.
I know you have some data from the internet, but what you describe as for
symptoms... in the context of the changes you made and the conditions under
which you read the plug... leads me to believe you went too far and
followed a process that is something other than best-practice-grade for
tuning your bike. Good luck.
--
Mike W.
96 XR400
70 CT70
71 KG 100 (Hodaka-powered)
99 KZ1000P (training)
99 KZ1000P (rider)
00 Beta Rev-3
Re: How long for a plug to color?
> Actually, I was. I gave you the best data I could toward your question...
> I've seen plugs change in 15-20 min. I don't have anything quicker than
> that.
A-ha. 20 minutes I can believe. It brings me back to the question of
validity of a plug chop test.
> I know you have some data from the internet, but what you describe as for
> symptoms... in the context of the changes you made and the conditions under
> which you read the plug... leads me to believe you went too far and
> followed a process that is something other than best-practice-grade for
> tuning your bike. Good luck.
Not really - there were enough people trying to solve the same problem
at the same time (big flood of '06 leftovers a few months back),
including James Dean of JD Jetting - who's solutions are known as the
be-all/end-all in certain circles. At any rate, I was tempted to take
a shot at a decent solution from the get-go, but instead chose to do a
couple of minor tweaks, basically in an effort to be able to do a warm-
up heat cycle w/out fouling the plug - that was my only goal, and I
succeeded.
The '05-07 125s being rich in the 1/8-1/4 throttle range is well
known. JDs kit solution is a custom needle with a fatter straight
section (pulled straight out of the 250 kit, evidently) and going 8
sizes smaller on the pilot. Personally, I think a slide with a leaner
cutaway is what really should be put in there, but a fatter needle
does pretty much the same thing.
I was able to instantly verify the rich condition at low throttles as
per needle, but I'm not so sure that the bike is too terribly rich on
the pilot jet itself. The ethanol effect was noticable though - as
the bike went from rich to lean through the needle range and felt lean
on top.
I have fond memories from a couple of years ago when they first
started putting ethanol in the gas - roughly 50% of the people I know
blew up their snowmobiles due to the resulting lean jetting. Who
knew?
JayC
> Actually, I was. I gave you the best data I could toward your question...
> I've seen plugs change in 15-20 min. I don't have anything quicker than
> that.
A-ha. 20 minutes I can believe. It brings me back to the question of
validity of a plug chop test.
> I know you have some data from the internet, but what you describe as for
> symptoms... in the context of the changes you made and the conditions under
> which you read the plug... leads me to believe you went too far and
> followed a process that is something other than best-practice-grade for
> tuning your bike. Good luck.
Not really - there were enough people trying to solve the same problem
at the same time (big flood of '06 leftovers a few months back),
including James Dean of JD Jetting - who's solutions are known as the
be-all/end-all in certain circles. At any rate, I was tempted to take
a shot at a decent solution from the get-go, but instead chose to do a
couple of minor tweaks, basically in an effort to be able to do a warm-
up heat cycle w/out fouling the plug - that was my only goal, and I
succeeded.
The '05-07 125s being rich in the 1/8-1/4 throttle range is well
known. JDs kit solution is a custom needle with a fatter straight
section (pulled straight out of the 250 kit, evidently) and going 8
sizes smaller on the pilot. Personally, I think a slide with a leaner
cutaway is what really should be put in there, but a fatter needle
does pretty much the same thing.
I was able to instantly verify the rich condition at low throttles as
per needle, but I'm not so sure that the bike is too terribly rich on
the pilot jet itself. The ethanol effect was noticable though - as
the bike went from rich to lean through the needle range and felt lean
on top.
I have fond memories from a couple of years ago when they first
started putting ethanol in the gas - roughly 50% of the people I know
blew up their snowmobiles due to the resulting lean jetting. Who
knew?
JayC
Re: How long for a plug to color?
On May 21, 12:51 pm, JayC <j...@sysmatrix,net > wrote:
> > Actually, I was. I gave you the best data I could toward your question...
> > I've seen plugs change in 15-20 min. I don't have anything quicker than
> > that.
>
> A-ha. 20 minutes I can believe. It brings me back to the question of
> validity of a plug chop test.
>
> > I know you have some data from the internet, but what you describe as for
> > symptoms... in the context of the changes you made and the conditions under
> > which you read the plug... leads me to believe you went too far and
> > followed a process that is something other than best-practice-grade for
> > tuning your bike. Good luck.
>
> Not really - there were enough people trying to solve the same problem
> at the same time (big flood of '06 leftovers a few months back),
> including James Dean of JD Jetting - who's solutions are known as the
> be-all/end-all in certain circles. At any rate, I was tempted to take
> a shot at a decent solution from the get-go, but instead chose to do a
> couple of minor tweaks, basically in an effort to be able to do a warm-
> up heat cycle w/out fouling the plug - that was my only goal, and I
> succeeded.
>
> The '05-07 125s being rich in the 1/8-1/4 throttle range is well
> known. JDs kit solution is a custom needle with a fatter straight
> section (pulled straight out of the 250 kit, evidently) and going 8
> sizes smaller on the pilot. Personally, I think a slide with a leaner
> cutaway is what really should be put in there, but a fatter needle
> does pretty much the same thing.
>
> I was able to instantly verify the rich condition at low throttles as
> per needle, but I'm not so sure that the bike is too terribly rich on
> the pilot jet itself. The ethanol effect was noticable though - as
> the bike went from rich to lean through the needle range and felt lean
> on top.
>
> I have fond memories from a couple of years ago when they first
> started putting ethanol in the gas - roughly 50% of the people I know
> blew up their snowmobiles due to the resulting lean jetting. Who
> knew?
>
> JayC
My XR650L was unrideable on E10 without a rejet, and that was with
richer-than-stock jetting.
Stock jetting it probably would have self-destructed.
Dave
On May 21, 12:51 pm, JayC <j...@sysmatrix,net > wrote:
> > Actually, I was. I gave you the best data I could toward your question...
> > I've seen plugs change in 15-20 min. I don't have anything quicker than
> > that.
>
> A-ha. 20 minutes I can believe. It brings me back to the question of
> validity of a plug chop test.
>
> > I know you have some data from the internet, but what you describe as for
> > symptoms... in the context of the changes you made and the conditions under
> > which you read the plug... leads me to believe you went too far and
> > followed a process that is something other than best-practice-grade for
> > tuning your bike. Good luck.
>
> Not really - there were enough people trying to solve the same problem
> at the same time (big flood of '06 leftovers a few months back),
> including James Dean of JD Jetting - who's solutions are known as the
> be-all/end-all in certain circles. At any rate, I was tempted to take
> a shot at a decent solution from the get-go, but instead chose to do a
> couple of minor tweaks, basically in an effort to be able to do a warm-
> up heat cycle w/out fouling the plug - that was my only goal, and I
> succeeded.
>
> The '05-07 125s being rich in the 1/8-1/4 throttle range is well
> known. JDs kit solution is a custom needle with a fatter straight
> section (pulled straight out of the 250 kit, evidently) and going 8
> sizes smaller on the pilot. Personally, I think a slide with a leaner
> cutaway is what really should be put in there, but a fatter needle
> does pretty much the same thing.
>
> I was able to instantly verify the rich condition at low throttles as
> per needle, but I'm not so sure that the bike is too terribly rich on
> the pilot jet itself. The ethanol effect was noticable though - as
> the bike went from rich to lean through the needle range and felt lean
> on top.
>
> I have fond memories from a couple of years ago when they first
> started putting ethanol in the gas - roughly 50% of the people I know
> blew up their snowmobiles due to the resulting lean jetting. Who
> knew?
>
> JayC
My XR650L was unrideable on E10 without a rejet, and that was with
richer-than-stock jetting.
Stock jetting it probably would have self-destructed.
Dave
Re: How long for a plug to color?
What is so freaking hard here.
Keeps going leaner on the pilot (with the air screw 2 turns out) until
you get the lean bog from 0-1/4 throttle and then go back to the next
bigger pilot. Now, you can use the plug readings to decide if your
main jet is too lean or rich. Next comes the needle. You can
experiment, buy a kit or call one of the companies that sells carb and
carb parts and ask them. They sell complete carbs pre jetted.
BTW, what brand carb is on your CR125?
Mike Baxter
On Wed, 21 May 2008 10:56:11 -0700 (PDT), XR650L_Dave
<spamTHISbrp@yahoo,com > wrote:
>On May 21, 12:51 pm, JayC <j...@sysmatrix,net > wrote:
>> > Actually, I was. I gave you the best data I could toward your question...
>> > I've seen plugs change in 15-20 min. I don't have anything quicker than
>> > that.
>>
>> A-ha. 20 minutes I can believe. It brings me back to the question of
>> validity of a plug chop test.
>>
>> > I know you have some data from the internet, but what you describe as for
>> > symptoms... in the context of the changes you made and the conditions under
>> > which you read the plug... leads me to believe you went too far and
>> > followed a process that is something other than best-practice-grade for
>> > tuning your bike. Good luck.
>>
>> Not really - there were enough people trying to solve the same problem
>> at the same time (big flood of '06 leftovers a few months back),
>> including James Dean of JD Jetting - who's solutions are known as the
>> be-all/end-all in certain circles. At any rate, I was tempted to take
>> a shot at a decent solution from the get-go, but instead chose to do a
>> couple of minor tweaks, basically in an effort to be able to do a warm-
>> up heat cycle w/out fouling the plug - that was my only goal, and I
>> succeeded.
>>
>> The '05-07 125s being rich in the 1/8-1/4 throttle range is well
>> known. JDs kit solution is a custom needle with a fatter straight
>> section (pulled straight out of the 250 kit, evidently) and going 8
>> sizes smaller on the pilot. Personally, I think a slide with a leaner
>> cutaway is what really should be put in there, but a fatter needle
>> does pretty much the same thing.
>>
>> I was able to instantly verify the rich condition at low throttles as
>> per needle, but I'm not so sure that the bike is too terribly rich on
>> the pilot jet itself. The ethanol effect was noticable though - as
>> the bike went from rich to lean through the needle range and felt lean
>> on top.
>>
>> I have fond memories from a couple of years ago when they first
>> started putting ethanol in the gas - roughly 50% of the people I know
>> blew up their snowmobiles due to the resulting lean jetting. Who
>> knew?
>>
>> JayC
>
>
>My XR650L was unrideable on E10 without a rejet, and that was with
>richer-than-stock jetting.
>
>Stock jetting it probably would have self-destructed.
>
>Dave
What is so freaking hard here.
Keeps going leaner on the pilot (with the air screw 2 turns out) until
you get the lean bog from 0-1/4 throttle and then go back to the next
bigger pilot. Now, you can use the plug readings to decide if your
main jet is too lean or rich. Next comes the needle. You can
experiment, buy a kit or call one of the companies that sells carb and
carb parts and ask them. They sell complete carbs pre jetted.
BTW, what brand carb is on your CR125?
Mike Baxter
On Wed, 21 May 2008 10:56:11 -0700 (PDT), XR650L_Dave
<spamTHISbrp@yahoo,com > wrote:
>On May 21, 12:51 pm, JayC <j...@sysmatrix,net > wrote:
>> > Actually, I was. I gave you the best data I could toward your question...
>> > I've seen plugs change in 15-20 min. I don't have anything quicker than
>> > that.
>>
>> A-ha. 20 minutes I can believe. It brings me back to the question of
>> validity of a plug chop test.
>>
>> > I know you have some data from the internet, but what you describe as for
>> > symptoms... in the context of the changes you made and the conditions under
>> > which you read the plug... leads me to believe you went too far and
>> > followed a process that is something other than best-practice-grade for
>> > tuning your bike. Good luck.
>>
>> Not really - there were enough people trying to solve the same problem
>> at the same time (big flood of '06 leftovers a few months back),
>> including James Dean of JD Jetting - who's solutions are known as the
>> be-all/end-all in certain circles. At any rate, I was tempted to take
>> a shot at a decent solution from the get-go, but instead chose to do a
>> couple of minor tweaks, basically in an effort to be able to do a warm-
>> up heat cycle w/out fouling the plug - that was my only goal, and I
>> succeeded.
>>
>> The '05-07 125s being rich in the 1/8-1/4 throttle range is well
>> known. JDs kit solution is a custom needle with a fatter straight
>> section (pulled straight out of the 250 kit, evidently) and going 8
>> sizes smaller on the pilot. Personally, I think a slide with a leaner
>> cutaway is what really should be put in there, but a fatter needle
>> does pretty much the same thing.
>>
>> I was able to instantly verify the rich condition at low throttles as
>> per needle, but I'm not so sure that the bike is too terribly rich on
>> the pilot jet itself. The ethanol effect was noticable though - as
>> the bike went from rich to lean through the needle range and felt lean
>> on top.
>>
>> I have fond memories from a couple of years ago when they first
>> started putting ethanol in the gas - roughly 50% of the people I know
>> blew up their snowmobiles due to the resulting lean jetting. Who
>> knew?
>>
>> JayC
>
>
>My XR650L was unrideable on E10 without a rejet, and that was with
>richer-than-stock jetting.
>
>Stock jetting it probably would have self-destructed.
>
>Dave
Re: How long for a plug to color?
On May 21, 6:01 pm, Mike Baxter <mgb...@comcast,net > wrote:
> What is so freaking hard here.
Getting an answer to the question I asked. It'll take me 15 minutes
to have my CR dialed in once I get the needle I want, which should
show up tomorrow. That's not the question - my only question is: How
long does it take for a plug to take on a color that is indicative of
jetting?
> BTW, what brand carb is on your CR125?
Mikuni (TMX38)
JayC
On May 21, 6:01 pm, Mike Baxter <mgb...@comcast,net > wrote:
> What is so freaking hard here.
Getting an answer to the question I asked. It'll take me 15 minutes
to have my CR dialed in once I get the needle I want, which should
show up tomorrow. That's not the question - my only question is: How
long does it take for a plug to take on a color that is indicative of
jetting?
> BTW, what brand carb is on your CR125?
Mikuni (TMX38)
JayC
Re: How long for a plug to color?
my jetski days reminded me to look here.....
http :// www .groupk,com /tec-carbs97.htm
"JayC" <jwc@sysmatrix,net > wrote in message
news:fa5927c4-a02a-4609-83b1-2d884167397c@x41g2000hsb.googlegroups,com ...
On May 21, 6:01 pm, Mike Baxter <mgb...@comcast,net > wrote:
> What is so freaking hard here.
Getting an answer to the question I asked. It'll take me 15 minutes
to have my CR dialed in once I get the needle I want, which should
show up tomorrow. That's not the question - my only question is: How
long does it take for a plug to take on a color that is indicative of
jetting?
> BTW, what brand carb is on your CR125?
Mikuni (TMX38)
JayC
my jetski days reminded me to look here.....
http :// www .groupk,com /tec-carbs97.htm
"JayC" <jwc@sysmatrix,net > wrote in message
news:fa5927c4-a02a-4609-83b1-2d884167397c@x41g2000hsb.googlegroups,com ...
On May 21, 6:01 pm, Mike Baxter <mgb...@comcast,net > wrote:
> What is so freaking hard here.
Getting an answer to the question I asked. It'll take me 15 minutes
to have my CR dialed in once I get the needle I want, which should
show up tomorrow. That's not the question - my only question is: How
long does it take for a plug to take on a color that is indicative of
jetting?
> BTW, what brand carb is on your CR125?
Mikuni (TMX38)
JayC
Re: How long for a plug to color?
On Wed, 21 May 2008 09:51:11 -0700 (PDT), JayC <jwc@sysmatrix,net > wrote:
>> Actually, I was. I gave you the best data I could toward your question...
>> I've seen plugs change in 15-20 min. I don't have anything quicker than
>> that.
>
>A-ha. 20 minutes I can believe. It brings me back to the question of
>validity of a plug chop test.
Actually, you might have the start of an answer. You say you did get color
at the base. Coloring usually starts on the porcelain adjacent to the
ground electrode and works its way around. I would take that to indicate
that the coloring starts on the hottest part of the surface first. The
hottest part is at the tip. Your plug might be done cooking.
>
>> I know you have some data from the internet, but what you describe as for
>> symptoms... in the context of the changes you made and the conditions under
>> which you read the plug... leads me to believe you went too far and
>> followed a process that is something other than best-practice-grade for
>> tuning your bike. Good luck.
>
>Not really - there were enough people trying to solve the same problem
>at the same time (big flood of '06 leftovers a few months back),
>including James Dean of JD Jetting - who's solutions are known as the
>be-all/end-all in certain circles. At any rate, I was tempted to take
>a shot at a decent solution from the get-go, but instead chose to do a
>couple of minor tweaks, basically in an effort to be able to do a warm-
>up heat cycle w/out fouling the plug - that was my only goal, and I
>succeeded.
>
Without mentioning names, there are two guys in the Mikuni world whose (the
possessive) solutions are considered to be the best... by some. And for at
least one of those two, the opposite by many others. The internet isn't
known for it's rich credibility.
>
>The '05-07 125s being rich in the 1/8-1/4 throttle range is well
>known. JDs kit solution is a custom needle with a fatter straight
>section (pulled straight out of the 250 kit, evidently) and going 8
>sizes smaller on the pilot. Personally, I think a slide with a leaner
>cutaway is what really should be put in there, but a fatter needle
>does pretty much the same thing.
Could be driven by the economics of available parts.
>
>I was able to instantly verify the rich condition at low throttles as
>per needle, but I'm not so sure that the bike is too terribly rich on
>the pilot jet itself. The ethanol effect was noticable though - as
>the bike went from rich to lean through the needle range and felt lean
>on top.
If the validation of the rich condition came from the cloud, could there be
an alternate explanation to "rich" for the presence of that cloud? I have
some ideas but nothing good enough to write down.
I'm still not quite sure if you followed a validated-good recipe or took a
swag. Either way, you seem to have solid evidence of a lean condition
despite the cloud and certainly touched literally everything you can to
have made a big move toward lean. Good luck... don't want your bike to get
screwed up.
M
>
>I have fond memories from a couple of years ago when they first
>started putting ethanol in the gas - roughly 50% of the people I know
>blew up their snowmobiles due to the resulting lean jetting. Who
>knew?
>
>JayC
--
Mike W.
96 XR400
70 CT70
71 KG 100 (Hodaka-powered)
99 KZ1000P (training)
99 KZ1000P (rider)
00 Beta Rev-3
On Wed, 21 May 2008 09:51:11 -0700 (PDT), JayC <jwc@sysmatrix,net > wrote:
>> Actually, I was. I gave you the best data I could toward your question...
>> I've seen plugs change in 15-20 min. I don't have anything quicker than
>> that.
>
>A-ha. 20 minutes I can believe. It brings me back to the question of
>validity of a plug chop test.
Actually, you might have the start of an answer. You say you did get color
at the base. Coloring usually starts on the porcelain adjacent to the
ground electrode and works its way around. I would take that to indicate
that the coloring starts on the hottest part of the surface first. The
hottest part is at the tip. Your plug might be done cooking.
>
>> I know you have some data from the internet, but what you describe as for
>> symptoms... in the context of the changes you made and the conditions under
>> which you read the plug... leads me to believe you went too far and
>> followed a process that is something other than best-practice-grade for
>> tuning your bike. Good luck.
>
>Not really - there were enough people trying to solve the same problem
>at the same time (big flood of '06 leftovers a few months back),
>including James Dean of JD Jetting - who's solutions are known as the
>be-all/end-all in certain circles. At any rate, I was tempted to take
>a shot at a decent solution from the get-go, but instead chose to do a
>couple of minor tweaks, basically in an effort to be able to do a warm-
>up heat cycle w/out fouling the plug - that was my only goal, and I
>succeeded.
>
Without mentioning names, there are two guys in the Mikuni world whose (the
possessive) solutions are considered to be the best... by some. And for at
least one of those two, the opposite by many others. The internet isn't
known for it's rich credibility.
>
>The '05-07 125s being rich in the 1/8-1/4 throttle range is well
>known. JDs kit solution is a custom needle with a fatter straight
>section (pulled straight out of the 250 kit, evidently) and going 8
>sizes smaller on the pilot. Personally, I think a slide with a leaner
>cutaway is what really should be put in there, but a fatter needle
>does pretty much the same thing.
Could be driven by the economics of available parts.
>
>I was able to instantly verify the rich condition at low throttles as
>per needle, but I'm not so sure that the bike is too terribly rich on
>the pilot jet itself. The ethanol effect was noticable though - as
>the bike went from rich to lean through the needle range and felt lean
>on top.
If the validation of the rich condition came from the cloud, could there be
an alternate explanation to "rich" for the presence of that cloud? I have
some ideas but nothing good enough to write down.
I'm still not quite sure if you followed a validated-good recipe or took a
swag. Either way, you seem to have solid evidence of a lean condition
despite the cloud and certainly touched literally everything you can to
have made a big move toward lean. Good luck... don't want your bike to get
screwed up.
M
>
>I have fond memories from a couple of years ago when they first
>started putting ethanol in the gas - roughly 50% of the people I know
>blew up their snowmobiles due to the resulting lean jetting. Who
>knew?
>
>JayC
--
Mike W.
96 XR400
70 CT70
71 KG 100 (Hodaka-powered)
99 KZ1000P (training)
99 KZ1000P (rider)
00 Beta Rev-3
