Will incorrect float height make the gs500 hard to start when cold? ie will take cranking to fill the float bowl?

-Fin

Even when hot...

With incorrect float height, it doesn't matter what you do, the bowl will never fill higher than its set to fill.  Ideally, the fuel level is constant. 

If the float is set too high it could possibly fowl the plugs causing hard starting. I'm not sure about the GS but on my present bike 1.5 mm on the float height is the difference between running great and running like crap.

I'm really bummed out here... I would like to sell the bike and move on, but I'm not prepared to let it go until I fix this start/idle problem.

When its cold, itll kick on the first start, turn over a few times, then die.

Try again...turns over a few more times....then dies

Try again...yet again a few more times....giving it throttle to keep it going...dies

eventually (after 1-2 minutes of starting), I am able to keep it going with just a bit of throttle on.


Starts up right away when warm.


Tomorrow will be checking valve clearances.

Monday will be getting new jets (20 pilot, one size up for mid and main). I have a k&n stock replacement.

-Fin

Ok, changed out the valve cover gasket and checked the valve clearances.

On the right (facing forward), intake was less than 0.036mm but the shim turns

Both exhaust shims less than 0.036mm, one on left turns, one on right does not...

Couldnt do anything about it cause I dont have the shim tool or shims. Is it better too tight than too loose?

How do clearances get smaller? I woulda thought wear would always make them larger...

Could this be my long cold start problem?


-Fin

Quote from: finmac on April 15, 2007, 05:59:10 PM
Is it better too tight than too loose?

How do clearances get smaller? I woulda thought wear would always make them larger...

Could this be my long cold start problem?

1.  Absolutely not!  Too tight means that your valves may not be sealing properly, leading to a burnt valve.

2.  As the steel valve hits the aluminum alloy head millions of times, it slowly causes the valve seat to deform, working its way up.

3.  Yes.

Ok. Heres the complete data:

2002 GS500 17.8k km
K&N stock replacement (no restrictor)
20 pilot
62.5 mid
135 main
no washers

mixture screw three turns out

float height about 3/4 cm above float bowl gasket line on both sides (will I need to correct this?)

both exhaust valves slightly tight

intake valves ok

stock exhaust

suburban machinery bar version 2

carbs cleaned thoroughly recently

Problems and Symptoms:

-Takes lots of cranking to get it started from cold
-Smells gassy when starting
-Will not idle at or near  1200rpm
-If idle set at or near 1200, hangs in the mid range
-Surging when going along in 1st
-Less surging going along when mixture set to 5 turns out.
-Popping out exhaust and air filter, especially under load at low rpms

Fine when its warmed up, good power, good throttle response, smooth downshifts

-Fin 

On an 02 I have noticed floats dont get adjusted by themselves as easily as an 89-00.
Of course someone may have gorilla fisted it ...
If not, leave it stock ... problem is else where ...
Petcock maybe ...
Cool.
Srinath.

Well I might have a go at adjusting the float heights.

Just went out and started it to try spraying the boots with flammable lube...no rev increase.

One more thing....when I hold the throttle constant...the rpms will often drop, as if its flooding itself and eventually stalls.

If your fuel level is truly as high as you say, then yes, you will be running rich.  It should be approximately level with the float bowl mating surface.  It's not a difficult thing to fix, though fixing it right may take a few adjustments.

Yeah I did the u tube test and its def not exactly level with the line (gasket) between bottom and top half of float bowl. Its about 1/2-3/4cm higher than that on both sides.

Once I have them out and apart, what internal measurement should I make? Also...because Ive rejetted is it advisable to have washers on the needles?

Well, just about every manual has the official procedure for measuring the float height.  I have never, ever gotten it to work like it's supposed to.  I used it previously to check whether my floats were in the correct carburetor.  Everything looked right, but when I checked the fuel heights, it was almost as badly off as yours.  My method is currently check and change and check.

Should the vacuum line be attached to the right or left carb when facing forwards? on a 2002

Try cleaning/replacing your plugs too. If it's runing rich or flooding out for a while, then you could foul up your plugs bad enough that it'll still run like crap after you get everything sorted out.

yeah Ill clean my plugs and double check the gap spacing.

I just finished adjusting the float height...lowered the u tube test a bit and seems to run somewhat better...tho still high.

Will high float height cause it it idle then "drown" itself....ie making restart hard cause of mild flooding?

-Fin
just pulled the plugs....some bad carbon fouling