I've got a '96 XR 628 with a Keihin carb on her. It will start cold, but as it gets hot, and runs for a while, you have to kick it about 10 minutes to get it to turn over. New plug, clean jets... What else can it be? It's almost as if it floods itself while running. Could the drainage tube be clogged? Any ideas out there?

If this bike worked OK for 'you' when 'you' rode it last and now it's having this problem at the same riding temperatures and altitudes it previsouly worked fine at for 'you', then the problem is most likely with the spark plug (you've already changed it), the jetting or some kind of electrical problem. Check all your wiring very closely.

If this is a new bike to you, or if you're riding this bike at significantly different altitudes or temperatures than you last rode it when everything worked OK, then the problem is likely in the jetting.

If a bike starts okay cold, but then is hard to start when it's hot (as youv'e said), then the pilot jet is likely too rich. This would be the first thing I'd change if I had this problem with my bike.

If your bike ever starts fine hot, but coughs when cold, the pilot jet is too lean and you can test this out by partially engaging the choke while your running. If it runs better at a lower throttle opening with the choke on, then it's a dead giveaway that the pilot jet is too lean.

Sounds good qadsan, You can try putting the choke on half way when its hot and if it starts better your too lean. I had that problem so I raised the needle one notch.

One thing I didn't hear mentioned was the valves. If there too tight you will have hot starting problems. Been there done that too.

YELLOWDOG- I have experienced a similar problem with an XR6 before. Check your stator (exciter coil). This coil supplies the spark and when the bike is started cold it would be fine, but the stator could be bad, causing intermittent spark problems when the coils are hot (warm engine). Check the resistance of your stator with a multimeter. Switch it to ohms x100 and measure the resistance of the exciter coil by putting one end in the red/white connector and one to ground, the measurement should be between 230 and 320 ohms, if it's a long way out of that range, replace or rewind the stator. Failing that, clean your carb and try different pilot jets.


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