hey all, need some advice, i have been working on my bros bike, 98 CBR F3, the thing will not start cold, and only after about 35 to 45 min of rolling over, it will finally start to spit and spudder, then start with the throttle wide open, run. here is the break down of what i have checked, timing is dead on, cams and crank, carbs have been cleaned, and synced, checked all wiring, and all is good. good spark, getting fuel, but heres the thing, when it finally starts, it runs great, until it cools down after stting for a bit. the only thing i havent done is valves, it has good compression too. if anyone has any ideas, please let me know.

 

does nobody have any ideas on what it could be?