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I'm having a cold cranking problem that I cannot seem to resolve. Bike is a '99 220, weisco piston, rechromed cyl, clean KIPS, stock carb, compression 160 psi. New jet block gasket. Won't start cold. After the first crank it will restart 1st kick, even before warm up. But that initial start of the day is a no go.
Acts sorta like it is flooded. It did not do this when I first got it, was a reliable 1-3 kick cold start then. All I've done is raise the idle a bit. Don't recall the jetting but 145 and 42 I think. Point is, I haven't changed the jets. Air screw is 1.5 out. New float valve with new viton (rubber) tip. Float height checked.

Installed my buddy's 35mm carb off his kdx200, and it cranks 1st kick again with his carb. Doesn't seem to matter which slide is in his carb, his or mine from the 220 carb. Seems pretty clear something is wrong with my carb. Question is...what? I'm out of ideas. Can the choke system be faulty? It looks clean and undamaged. Again it cranks flawlessly hot or even slightly warm, just not cold. Only exception is it often cranks cold right after I've disassembled, cleaned and reassembled . Not always though.
I need some experienced feedback before I just throw up my hands and buy a new carb!

What is your starting technique? (choke, amount of throttle open)

Is it warmer now than when you were having good success before?

First start, choke pulled, just a crack of throttle, maybe 1/8th? Haven't changed technique. No change in outside air temp. This has been going on for some time, like well over a year.
What really made me decide it must be some unrecognized carb problem is the thing cranks great when I swap carbs.

Did you compare float height on the two carbs?

I would think it has to be a restriction in your choke circuit.

Does the choke knob stay up when pulled?

I've had an on-and-off problem with the choke knob not staying up.

The zip tie trick around the choke rod boot usually works to hold the rod up, but then I'll go back and when I pull the choke up, it won't click into it's detent to stay up. Snipped off the zip tie and it stays up. Some time later try again and it won't stay up. Add zip tie again .......... I suppose I need a new choke assembly, but even with a new assembly, I'll probably have to add a zip tie again at some point.

My guess is the choke circuit (considering that the other carb worked right away) and on yours I don't imagine you're using the choke for the second start up. Do you have to bump start it to get it going when cold? If it were mine I would:

1) Remove the choke and run a pipe cleaner, or long jet cleaner through the circuit and then blow compressed air down the chute and also through the hole in the back of the carb that leads to the choke. Those V shaped air compressor nozzles with the rubber tip are perfect for that.
2) Install a different pilot jet, even if its the same size.
3) Install a new spark plug gapped to spec.
4) Remove the spark plug boot, snip a 1/4" off of the wire, and reinstall.
5) Adjust the air screw to 1 turn out for a few kicks and then 2 turns out for few kicks when the engine is cold. *I would do this first since its the easiest

Float height was almost identical on the two carbs. Choke knob stays up and appears to work correctly. I've sprayed carb cleaner thru the choke passages and compressed air. Have not put anything solid (wire, pipe cleaner, etc) through them. Certainly willing to try.

I like the idea of switching pilot jets. Maybe I'll swap jets from the other carb at least as a test.
Guess you are thinking weak spark on the plug wire cut off? Worth a try but that wouldn't explain why it cranks so easily with the other carb I don't think. Already tried multiple new plugs with no effect.
Other thing I haven't tried is swapping out the choke knob assemblies between the two carbs. I'll do that too.
Thanks for the input for you guys.

doakley wrote:Float height was almost identical on the two carbs. Choke knob stays up and appears to work correctly. I've sprayed carb cleaner thru the choke passages and compressed air. Have not put anything solid (wire, pipe cleaner, etc) through them. Certainly willing to try.

I like the idea of switching pilot jets. Maybe I'll swap jets from the other carb at least as a test.
Guess you are thinking weak spark on the plug wire cut off? Worth a try but that wouldn't explain why it cranks so easily with the other carb I don't think. Already tried multiple new plugs with no effect.
Other thing I haven't tried is swapping out the choke knob assemblies between the two carbs. I'll do that too.
Thanks for the input for you guys.

I am curious on the choke assembly swap.

Me too. Think I’ll start there . I’ll report back. Unfortunately it may be a while. Due to a little medical procedure I don’t think I can kick it right now.

Update on cold cranking. I cleaned the pee out of the choke assembly, passages, etc. put in yet another new plug just for grins, and it has been cranking on the first kick consistently for the last 4 days! Hoping there was some blockage in the choke after all and the problem is solved. Feel pretty lame because I thought I had cleaned everything before but perhaps not. I’ll report back if the problem rears it’s ugly head again. Gotta’ love the help you get from this group.

Huh, new spark plug the whole time.



I am glad it seems to have been repaired.

I don’t believe it was the plug. I’ve put in multiple new plugs in the past with no improvement. I’m pretty sure there was something in the choke passages that I had not adequately cleaned.
Whatever, it continues to crank on the first kick so I’m a happy camper at the moment.

I was just being a dork.