Rebuilt XR600 is very difficult to start hot

[michaelschorpp]

I've put about 100 miles on my rebuilt 92 XR600R. The only problem I've noticed is very hard hot-starting. Cold starts are 1-2 kicks but some hot starts take 10 minutes, and 20-30 kicks. The bike is being stopped normally.

I'm also getting the occaisional backfire and kickback (not at the same time) when trying to start hot. The bike never did that before. During the rebuild I did have the camshaft diassembled to replace the automatic decompressor cam.

I don't know what my carb is jetted to (it has a quiet Cobra ISDE exhaust) but it has always belched black soot when I start it up.

Any suggestions?

Mike.

[XR6's_rule]

Sounds like its running a little rich. I would clean the airfilter then adjust the airscrew first, set it at around 2-2 1/2 turns out from screwed right in. Failing that, you may have a too richer pilot jet. Try a leaner one (one size smaller at a time) till you clean it up. Also whack in a new sparkplug while your at it and if you know how, check the valve clearances, as a tight valve will cause hard starting when the engine is warm. Cheers,

Mark.

[pressurefreak]

Maybe a dumb question, are you using the hot start procedure of holding in the decomp lever 4 or 5 kicks then trying it. I don't even know if the 92 has a decomp lever. It works great on my 87xr600. Just a thought ?

[Mantrasonica]

I don't know what my carb is jetted to (it has a quiet Cobra ISDE exhaust) but it has always belched black soot when I start it up.

Any suggestions?

Mike.

What color is the plug. My guess is its black. Look at the carb. Sounds like its running fat.

[frankstr]

Black soot on start up....sounds rich to me....... ?