Starting problems on 2008 crf250

[Foxracer61]

I bought this 2008 crf250r just last month rode it about six times. I have starting problems with it ever since i got it but dont know why. I checked the valves just the other day and they were in spec it said you can be within a thousanth of a difference which we were. I change the leak jet and the main to see if it would get rid of the bog and the main and it seemed to make the bog worse so i put the stock one back in it. But still wont start cold, if its hot it will start right up first or second kick. Some times it will start cold but then later that day it will not and i have to bump start it! What is the deal its petty well a brand new bike please help!

[ebeck]

Did you replace the leak jet with a smaller or larger numbered numbed jet? Smaller in richer which is what you need here. That is contrart to the other jets.

The main jet has nothing to do with starting and probably nothing to do with the bog, but did you go with a smaller or larger numbered jet on the main?

Do you kick it over slow until the decomp clicks and then twist the throttle twice and kick hard? 4 strokes take some technique to start. This assumes you turn the fuel on and wait 15 seconds or so. The bowl should be full first.

You really can not hop on these and start kicking like it is a 2 stroke. It is worth mentioning that the bike should be in Neutral unlike a 2 stroke where you just pull the clutch and kick away if your in gear.

[RallyImprezive]

Do you kick it over slow until the decomp clicks and then twist the throttle twice and kick hard? 4 strokes take some technique to start.

+1 on that. It makes all the difference in the world when you follow that process. ?

[ebeck]

If it an an 08 the leak is a 70 stock go to a 65 which is richer. Pre 07 bikes had 45 leak jets.

[grunkthump]

is a 45lj TOO rich on an 08'?? or will it work ok?? (using 42pj)

[Foxracer61]

Well i had an 04 rmz and you could not give it any throttle before starting it, which it would start 1st or second kick everytime! We went smaller a 65 on the leak jet. and put stock main in it! thats all we did but it had the starting problem before i changed it!

[tmauto69]

Same exact problem I had with mine, I tried changing every jet in every direction trying to remedy it, but nothing worked. I bought a JD jetting kit for it and it helped a little (little meaning only 15mins kicking it instead of 20). Also giving it about 10 twists of the throttle seemed to work better sometimes. Once it was running the thing would run like a bat out of hell, but the cold start issue with that bike resulted in me trading it on an 09 450r. Funny thing is I have an 07 250r that starts warm or cold without issue always.

[grunkthump]

how are the 09's cold?? the decomp. mod and a QS2 and jetting changes really did nothing for me when the bike is cold...yesterday it was upper 30's here...hauled the bike to an indoor track unloaded let it sit inside for 20minutes while signing up/changing...had to kick at LEAST 50times to start it!! ridiculous!!

[ebeck]

My 07 had little problem starting, even after I swapped to a JE 13.5 piston. I thn put the 08 cam in (I avoided the 09) and the 280 kit and from time to time I have to kick like 20 times even when warm.

Sometimes it starts first kick with 2 throttle twists. Sometime it refuses to start. Sometimes starts warm easy oyther times I almost have to leave due to inability to start it. Really odd.

I fing if I twist the throttle like a 2 stroke when kicking (not supposed to) it works. Think I will try a richer pilot jet next.