Desperate!!

 2002 WR 250 F, when cold starts with one kick. When hot won't start even if you kick it 100 times. Yes I use the hot choke. Go through the same sequence as a coldstart. But no matter what the bike just doesn't want to start. Any advice is greatly appreciated.

48 minutes ago, ctdrules said:

 2002 WR 250 F, when cold starts with one kick. When hot won't start even if you kick it 100 times. Yes I use the hot choke. Go through the same sequence as a coldstart. But no matter what the bike just doesn't want to start. Any advice is greatly appreciated.

I had the same problem. I was the rubber between carb and cylinder that had cracks. Try when it's cold to start it. Then spray starter gas on the outside and se if it changes. 

Check your valve clearance. Typical symptom of right valve clearance.

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1 hour ago, speedtoad said:

Check your valve clearance. Typical symptom of right valve clearance.

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Will do. 

Bikes with tight valves won't start when cold but will start when warm.  His problem is the revers.

 

Bikes with tight valves won't start when cold but will start when warm.  His problem is the revers.
 


I think you have it backwards. Common symptom is won't kickstart when hot but can be bump started.

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Bikes with tight valves won't start when cold but will start when warm.  His problem is the revers.
 

Interesting. I've rebuilt my 08 yz250f 3 times. My bike must be different then all the others.

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My 01 250f was a pain to start ended up being tight exhaust valves. I bet he is running to rich. Try leaning the fuel mixture to let more cool air through the carb should make for an easier hot start.

Question: When it is running, and you speed up, shift up to 2nd, speed up, then let off, does it pop on deceleration?

Also, do you use choke when cold?

From your description, I would guess not on both questions.  That would be a rich condition.  It should be adjusted so that choke is needed when cold, and it should pop on deceleration.

I assume main jet is 170, pilot jet is .040, main jet needle clip in 3rd clip position from top.  Your fuel screw should be somewhere around 2.5 to 3 turns out, no more than 3 turns out.  William1 fuel screw procedure for adjustment.

Only other thing that would cause it to be rich is high float level, or leaking float valve.

 

I would look at the stator.  Had very similar symptoms on a WR450F and a CRF450R.  In both cases, the bike would have issues when warm because the wires in the stator would expand and short.  

Valves are too tight for sure. Will it push start when warm? 

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