[mprentice]

So I'm trying to get a starting point for diagnosis on my sons 2012 CRF250R. We just had the motor rebuilt, top and bottom.

Took it out to the track today and the bike seems to run great...that is, once we get it started and warmed up. It probably took me 30 kicks to get it started when it was cold, but for the rest of the day, it started fine - Most of the time it started in 1-2 kicks, no problem. Ambient temperature was about 85 degrees when we started.

Now, it did this yesterday too, when I was testing it in my driveway. Again 30 kicks, then finally it starts. I got it up to operating temp, shut it off and then re-start and it starts fine. Something is happening when it cools down.

Valve clearances are all within spec. Should I be first looking at something fuel related? Blockage? Fuel pressure? Or would something like this point to electrical? It ran fine with no backfiring or anything abnormal that I would think would point to timing.

Has anyone else experienced this before?

[JimDirt]

Check the Throttle Cable Play , when you reassembled it , you must have mis-adjusted the throttle cable , the sensors will think it has the throttle on when the cable is too tight , which changes the mixture , which is more critical when cold , give the cable some slack and it should start right up when cold ...hopefully....

[mprentice]

So it's been a couple weeks- thought I would post a follow-up. It seems to be getting better. I'm down to about 4-5 kicks from cold, which I guess is somewhat acceptable. Disappointing overall, because before the rebuild from a so-called Honda certified monkey-bike mechanic, the thing started in 1-2 kicks every single time....stone cold

The throttle cable seems to be ok - not too tight. I checked the valve clearances, (now)they are ok,(despite just getting it back from a complete rebuild. Long story, but you can see my thread under "can you ID this foreign object" in this same forum).

Is it possible to get air in the fuel line if I took off the tank? or changed out the fuel filter?

Not really sure what else to check. I guess I will keep an eye on it and see what happens.

[JimDirt]

No , air would not be from removing the tank , it would seem to be a starvation issue when cold , it will start easily when hot because if its lean/starving , it will start easier hot (thats what the Hot Start does , it leans the system out and allows it to start easier when warm) , so i would look into something to do with fuel still , so make sure the Fuel Filter is working correctly , and make sure the Fuel Pump does not have any issues , i believe they did a "upgrade" to the pump at one point , so you should check into that with the Honda Dealer (not sure if it was a recall , or something that needs to be done on your year)

PM Ken , he could probably tell you if your bike has a fuel pump issue that is known

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