Bike won't start after carb cleaning.

Bike won't start after carb cleaning.

Hi all, back again with another sport bike - this being a classic, a
83 Kawi GPz305, belt drive - the forerunner to the Ninja and all the
fast toys today, and a treat to ride. Well, at least it should be if I
can get it going again.

Got this little guy recently, it had been parked outside and neglected
by the owner. Great fixer upper and already looking great, as
everything is in place and will make a superb bike for the wife.

Here's the problem and I'll provide as much detail as possible, so be
prepared for a long read. This is quite a puzzle.

When I first got the bike it would run but mostly off one cylinder. I
could tell that the left pipe (just off the engine) was hot while the
right pipe was barely lukewarm. I tested the sparks and it was
sparking fine on both cylinders (even put on new spark plugs). A
friend said it clearly was a clogged carb, which I agreed. At this
stage the bike would start very nicely, very easily. I had just put a
new battery in it and it started like a new bike, despite the obvious
lack of fuel to both cylinders.

So the next step was to take off the carb for a complete clean. Took
everything apart, inspected all the jets, needles, diaphragm, etc.
Everything looked great after a good cleaning, as it had varnish and
what appeared to be green sand everywhere. As it turns out the petcock
was defective and even though the owner thought the fuel was off, it
wasn't. So for over a year fuel kept on going through the carb. Ouch.

Btw I did not remove the carbs off the rack, just opened them up on
both ends and cleaned it completely. I used Yamaha's Combustion
Chamber Cleaner which is supposed to be a better form of carb cleaner.
Used a toothbrush and carefully cleaned every corner, every jet, every
tiny hole I could find.

Put carbs back on bike and it wouldn't start easily. Drained the
battery (again, brand new) to the point where I had to use my car to
boost it. After some effort it did fire up but run horrible. Idle was
all over the place, inconsistent and very rough.

Out comes the carbs again, for a second cleaning and a total
inspection to ensure I hadn't miss anything. Back on the bike goes the
carbs. This time it started a bit easier (with choke full on) and it
run beautifully. Although I had to have the choke on for several
minutes, the engine sounded great and idle was consistent. After
warming it up nicely, I was able to lower the choke till just past the
halfway mark. Any lower the engine would die. At this stage all seemed
well, I would turn off the engine and the bike would fire up nicely
with a brief press of the start button. Bike run through the gears
fine and seemed to have plenty of power. All seemed well and fixed. I
kept on riding the bike around the block till the engine got nice and
hot. Perhaps too hot? Cause at one point it just died, like it had a
few previous times while running and you just knew that it would be a
bitch to start again.

After waiting till the engine cooled, I attempted to start it again.
No go. It turns fine and sounds good, it just won't fire. I'm trying
to start it with a boost from my car (car running) and no go. I have
the choke full on and everywhere in between. I have the air screws set
from one turn to 2.5 turns out and this too didn't help. Spark is nice
and strong on both cylinders. I know the carb is getting fuel as I see
it in the float bows (after draining it). All systems seem fine but
the thing just refuses to start. The puzzler is, when it does start it
seems to run great (albeit with the choke still on and some backfire
due to this) till it gets hot and dies again. Except that now I can't
get it to start at all, even with a boost from the car and several
minutes of trying.

Is there a trick to getting this bike to start nicely again? Remember,
prior to me cleaning the carb it would start nice each time so I don't
think it is a starter problem but it points more to a carb issue. I
didn't play with the float bows as they seemed fine and level. The
throttle and choke butterfly all seem to open and close at the same
time. The diaphragm seems good and rides up and down nicely. In fact
the whole carb looks good on the inside. I suspect I may have to pay a
mechanic to adjust the carbs but I wonder if there is some minor
adjustment I can make in order to get it to fire up the bike. I mean,
since it seems to run well when it fires up, it makes me think that
the carbs are pretty close to being sync'ed.

This is driving me crazy. Please help.

Re: Bike won't start after carb cleaning.


"Eat Dirt" <eatdirt339@gmail,com > wrote

> This is driving me crazy. Please help.

You didn't mention cleaning the tank/screens and/or installing a fuel
filter.
The carbs may be plugged up yet again.
The stopping after heating up may be a plugged gas tank vent........or an
ignition part failing when hot.

Re: Bike won't start after carb cleaning.

On Apr 8, 10:19 am, "Who Me?" <hitchhi...@dont.panic> wrote:

> You didn't mention cleaning the tank/screens and/or installing a fuel
> filter.

Guess I wasn't as detailed as I wanted: yes, I did clean the gas tank
inside as it had tiny specs of rust. I also removed and rebuilt the
petcock (since this had a worn out o'ring and wasn't sealing) and
ensured the fuel filter is clean. So I don't suspect that more dirt
got into the carb. The second time I took the carb apart and cleaned
it, it didn't have any more dirt in it.

Someone suggested soaking the carb in cleaner overnight. I did not do
this as I thought I could just clean it with a toothbrush. Could a
small amount of varnish or dirt be present in some tiny passageway and
could this be the cause of all my headache?

Re: Bike won't start after carb cleaning.

Eat Dirt wrote:
...
> Someone suggested soaking the carb in cleaner overnight. I did not do
> this as I thought I could just clean it with a toothbrush. Could a
> small amount of varnish or dirt be present in some tiny passageway and
> could this be the cause of all my headache?


I'm not as expert about carbs as some here, but I know that for sure the
little jets and float passages can easily have gum or dirt that you'll
never see if you don't at least blow them out. I use just a very small
air compressor for that, but if I have the carb off always soak first.
One guy uses Pinesol to soak his carbs with, but if a soap is used
you'll want to be sure to blow dry very thoroughly. Some people just
use one of those air tanks you can fill at the gas station and some even
use the air in their car tires! I guess there might be enough air in
the bike's tires to blast a passage or two for a few seconds. That's
what I'd try as long as I had a bicycle pump handy and I'd probably be
less unfit to boot.

Re: Bike won't start after carb cleaning.


"Eat Dirt" <eatdirt339@gmail,com > wrote

>Someone suggested soaking the carb in cleaner overnight. I did not do
>this as I thought I could just clean it with a toothbrush. Could a
>small amount of varnish or dirt be present in some tiny passageway and
>could this be the cause of all my headache?

Yes, possible. The compressed air suggestion is also good.......just
protect your eyes. Carb cleaner STINGS!!

Re: Bike won't start after carb cleaning.


"Who Me?" <hitchhiker@dont.panic> wrote

> Yes, possible. The compressed air suggestion is also good.......just
> protect your eyes. Carb cleaner STINGS!!

Uh, last time I looked, it was also poisonous...

Re: Bike won't start after carb cleaning.


"P. Roehling" <nowayjose@uh-uh.edu> wrote

>> Yes, possible. The compressed air suggestion is also good.......just
>> protect your eyes. Carb cleaner STINGS!!
>
> Uh, last time I looked, it was also poisonous...

I'm sure. Maybe toxic would be a better description since I don't think a
few drops (applied anywhere) will KILL you.......or even make you deathly
ill.

Re: Bike won't start after carb cleaning.


"Who Me?" <hitchhiker@dont.panic> wrote

>>> Yes, possible. The compressed air suggestion is also good.......just
>>> protect your eyes. Carb cleaner STINGS!!
>>
>> Uh, last time I looked, it was also poisonous...
>
> I'm sure. Maybe toxic would be a better description since I don't think a
> few drops (applied anywhere) will KILL you.......or even make you deathly
> ill.

The warnings on my can say "HARMFUL OR FATAL IF SWALLOWED. VAPOR HARMFUL.
HARMFUL IF ABSORBED THROUGH SKIN.

FIRST AID: IF SWALLOWED, GIVE 1 TO 2 GLASSES OF WATER AND CALL A PHYSICIAN,
HOSPITAL EMERGENCY ROOM OR POISON CONTROL CENTER IMMEDIATELY.

Sounds like poison to *me*.

Re: Bike won't start after carb cleaning.


"P. Roehling" <nowayjose@uh-uh.edu> wrote

> Sounds like poison to *me*.
>
Well ya, if you drink the stuff, so is gasoline! ;-)

Re: Bike won't start after carb cleaning.

On Wed, 09 Apr 2008 11:15:59 -0700, P. Roehling wrote:

> "Who Me?" <hitchhiker@dont.panic> wrote
>
>>>> Yes, possible. The compressed air suggestion is also good.......just
>>>> protect your eyes. Carb cleaner STINGS!!
>>>
>>> Uh, last time I looked, it was also poisonous...
>>
>> I'm sure. Maybe toxic would be a better description since I don't
>> think a few drops (applied anywhere) will KILL you.......or even make
>> you deathly ill.
>
> The warnings on my can say "HARMFUL OR FATAL IF SWALLOWED. VAPOR
> HARMFUL. HARMFUL IF ABSORBED THROUGH SKIN.
>
> FIRST AID: IF SWALLOWED, GIVE 1 TO 2 GLASSES OF WATER AND CALL A
> PHYSICIAN, HOSPITAL EMERGENCY ROOM OR POISON CONTROL CENTER IMMEDIATELY.
>
> Sounds like poison to *me*.

Also remember though in what country you are reading these labels. If
they don't spell it out like that and some idiot decides to go shove the
can into his mouth and drink the contents in in it's entirety then the
manufacturer can get sued for his stupidity. Personal responsi...what?

I mean swallowing carb cleaner is pretty damn difficult unless you
deliberately do so.

I used to work cars for a living for a while and I've breathed in more
than enough assorted carb cleaner, brake cleaner, whatever cleaner fumes
without any ill effect. Yes you'd probably not want to be stuck in an
enclosed space with fumes all around you...but you aren't going to be
harmed by the odd fumes that result from normal everyday usage.

Even the skin thing, you'd likely have to go take a bath in the stuff for
a few hours to actually absorb any significant enough amount. Shit, I
used to wash my hands with break cleaner on occasion when they were so
damn dirty nothing else worked..,it actually was easier on my skin than
scrubbing them all the time with a near-sandpaper-like sponge. I'd of
course rinse the cleaner off with water afterward and not leave it
sitting on there.

Bottom line, you're very unlikely to be harmed by it through normal use.
You'd have to deliberately try to hurt yourself in order to succeed.

--
Stephan
1986 Pontiac Fiero GT

???????????????
?????????????

Re: Bike won't start after carb cleaning.

P. Roehling wrote:
> "Who Me?" <hitchhiker@dont.panic> wrote
>
>>>> Yes, possible. The compressed air suggestion is also good.......just
>>>> protect your eyes. Carb cleaner STINGS!!
>>> Uh, last time I looked, it was also poisonous...
>> I'm sure. Maybe toxic would be a better description since I don't think a
>> few drops (applied anywhere) will KILL you.......or even make you deathly
>> ill.
>
> The warnings on my can say "HARMFUL OR FATAL IF SWALLOWED. VAPOR HARMFUL.
> HARMFUL IF ABSORBED THROUGH SKIN.
>
> FIRST AID: IF SWALLOWED, GIVE 1 TO 2 GLASSES OF WATER AND CALL A PHYSICIAN,
> HOSPITAL EMERGENCY ROOM OR POISON CONTROL CENTER IMMEDIATELY.
>
> Sounds like poison to *me*.
>
>

Poison is purely a matter of dosage.
In small enough dose, nothing can kill you.
In large enough dose, anything can.

Re: Bike won't start after carb cleaning.

On Apr 8, 8:41 am, Eat Dirt <eatdirt...@gmail,com > wrote:

> Is there a trick to getting this bike to start nicely again?

Your idle jets are all plugged up. Remove the idle mixture screws and
spray Berryman's B12 or STP or GumOut carb cleaner through all the
idle mixture ports, including the three acceleration transition ports
located near the lower edge of the throttle butterflies.

The engine draws fuel through the idle jets and air through the pilor
air jet which may be in the inlet bell or under the rubber diaphragm.
Then the mixture goes off to the single idle mixture port behind the
idle mixture screw and to the three acceleration ports.

Spraying carb cleaner through the pilot air jet and the idle jet
should result in a strong stream of fuel air mixture coming out of
each port.

I cannot advise you as to how many turns open your idle mixture screws
should be, because it depends on the area of the orifice in the idle
jet, and the area varies exponentially as to the square of the radius
of the jet.

Some bikes have tiny idle jets, like #30 to #35 and they need the idle
mixture screw to be turned out 3 to 3-1/2 turns.

Other bikes have huge #40 to #45 idle jets and the idle mixture screw
only needs to be turned out 1/4 of a turn.

When starting the motorcycle, the choke should be fully "ON" and the
throttle should be fully closed to avoid uncovering the three
acceleration transition ports, which makes the idle mixture far too
rich.

Re: Bike won't start after carb cleaning.

On Apr 9, 10:22 am, Nameless 1 <Rhiann...@gmail,com > wrote:
> On Apr 8, 8:41 am, Eat Dirt <eatdirt...@gmail,com > wrote:
>
> > Is there a trick to getting this bike to start nicely again?
>
> Your idle jets are all plugged up. Remove the idle mixture screws and
> spray Berryman's B12 or STP or GumOut carb cleaner through all the
> idle mixture ports, including the three acceleration transition ports
> located near the lower edge of the throttle butterflies.
>
> The engine draws fuel through the idle jets and air through the pilor
> air jet which may be in the inlet bell or under the rubber diaphragm.
> Then the mixture goes off to the single idle mixture port behind the
> idle mixture screw and to the three acceleration ports.
>
> Spraying carb cleaner through the pilot air jet and the idle jet
> should result in a strong stream of fuel air mixture coming out of
> each port.
>
> I cannot advise you as to how many turns open your idle mixture screws
> should be, because it depends on the area of the orifice in the idle
> jet, and the area varies exponentially as to the square of the radius
> of the jet.
>
> Some bikes have tiny idle jets, like #30 to #35 and they need the idle
> mixture screw to be turned out 3 to 3-1/2 turns.
>
> Other bikes have huge #40 to #45 idle jets and the idle mixture screw
> only needs to be turned out 1/4 of a turn.
>
> When starting the motorcycle, the choke should be fully "ON" and the
> throttle should be fully closed to avoid uncovering the three
> acceleration transition ports, which makes the idle mixture far too
> rich.

Thanks, I did what you said and I have cleaned the air mixture screws,
which were indeed dirty. I also fully cleaned each and every tiny hole
by spraying carb cleaner through them. Now I feel that this carb is
fully clean. But I suspect I found a problem: my diaphragm and its
cylinder may not be working as it should. What do you think of this?
The manual says that in order to test it, I should place the carb
upright, cover the inlet air hole, push the cylinder way up and time
it as it slowly descends. It claims it should take over 10 seconds.
Well, in my test one of them took 6 seconds while the other only took
3 secons. Is this bad? I hope I don't have to replace these as I
suspect they'd cost a small fortune. But could this be causing
starting problems and causing the bike to run lean as well?

I plan to install the carb back on the bike later tonight to test it.
Although I'm now wondering if I'd be better first bringing it to a
mechanic to properly adjust the float levels. The bike is clearly
running very lean (white spark plug contacts, overheating, need for
the choke to be on, etc). Do you think this to be a good idea too?
Thanks for the help.

Re: Bike won't start after carb cleaning.

Eat Dirt wrote:

> On Apr 9, 10:22 am, Nameless 1 <Rhiann...@gmail,com > wrote:
>
<snip>
> Thanks, I did what you said and I have cleaned the air mixture screws,
> which were indeed dirty. I also fully cleaned each and every tiny hole
> by spraying carb cleaner through them. Now I feel that this carb is
> fully clean. But I suspect I found a problem: my diaphragm and its
> cylinder may not be working as it should. What do you think of this?

It should still start with a bad diaphragm. A bad diaphragm just makes
it so it won't take full throttle.

Sorry if I missed it in another post, but are you sure you didn't pinch
a gas line when you bolted the tank back on? I do this myself more often
then I would like to admit.

Anyway, the little brass drain plugs on the bottom of the carburetor are
a wonderful diagnostic device. What I do is with the petcock in the OFF
position remove the plug and catch the gas that falls. If it is the
~right volume I turn the petcock on and see if there is adequite flow.
If gas flows with the petcock off, time to replace the petcock.

This may take longer to tell then it is worth, but you really have to
flush the carbs in the right direction or verify flow. That is, when you
use the little tube that came with your carb cleaner to spray cleaner
into the slow jet, it should have a steady stream of cleaner comming out
of a tiny hole on the engine side of the butterfly valve. It will also
come out one of the holes on the intake side of the carburator if you
have the idle screw out a couple of turns.

Sometimes the little flakes/crud form is between the jet and this exit.
I just pull a steel wire out of a wire brush to poke it open. Ditto for
the slow jet.

Rick

Re: Bike won't start after carb cleaning.

On Apr 9, 11:37 am, Rick Cortese <ricor...@earthlink,net > wrote:
> Eat Dirt wrote:
> > On Apr 9, 10:22 am, Nameless 1 <Rhiann...@gmail,com > wrote:

> It should still start with a bad diaphragm. A bad diaphragm just makes
> it so it won't take full throttle.

> Sometimes the little flakes/crud form is between the jet and this exit.
> I just pull a steel wire out of a wire brush to poke it open. Ditto for
> the slow jet.
>
> Rick

Not sure how a thread about a bike not starting turns into an idiotic
debate on how sniffing carb cleaner to kill you and cause your wife to
give birth to a 7 headed monster but for those that actually tried to
help, here's an update:
Installed the carb after a 4th attempt at cleaning it - and the thing
fired right up! Wow, I couldn't believe it. It's like a new bike now
and works absolutely well (despite being too lean). Here's what I
think happened (for those thread jackers that have a hard on for carb
cleaner you'll like this). I had initially used Yamaha's combustion
chamber cleaner to clean out the very gross varnish and greenish sand
that was the inside of both carbs, due to a friend's recommendation. I
noticed that it left a somewhat thick, very shiny and slippery residue
on everything it touched. I figured that gasoline would just clean
that out once gas run through it. Well, it actually didn't. A guy at
local shop said that some of the jets need to be exceptionally clean
as it is very sensitive to anything (the jets responsible for idling
and starting). Suspecting the combustion cleaner was the problem, I
picked up a can of carb cleaner (thread hijackers, pay attention) and
completely cleaned everything over again, leaving a dry, crisp
surface. I also sprayed it through every hole, which inevitably
backsprayed onto my eyes and face. Guess what folks: I can still see
and despite even tasting it, I managed to survive.

I still have one problem though: bike is still running too lean. I
have set the air screws to only half a turn despite the manual
recommendation for 1.75 turns from completely closed. I figured that
by letting less air in that it would richen the mixture. Well, I still
get a whitish spark plug and I noticed the engine seems to be running
very hot even though this is an air cooled bike and the bike was
mostly idling in place. However I no longer need to have the choke on
for the bike to idle, which is a sign that I'm on the right path.

What can I do to richen the mixture? I don't think replacing the jets
to be the answer as previous to my carb cleaning the bike was running
properly, as seen on the old spark plugs that looked 'normal'. Any
tweaks I can do?