so my bike has a k&n filter and full vance and hines exhaust. when i got it i noticed about 50 mph or so it would start stuttering and after it did that it pretty much does it 35 mph and up. I installed a dynojet stage1 kit with the 126 main jets it called for and the needles are on position 2 and installed the shims correctly. it seems to run fine in the morning on my 20 minute jaunt to the park and ride. on the way home for some reason the hesitation comes back when the bike is warmer. i notice a little tick in the exhaust pipe when its ideling and since i installed the kit it has a little backfire when i decelerate. the jets that took out were 138's... and the air mixture screw is set at 1.5 turns like it said to do. i noticed one of my intake valves is leaking by when i got the bike too... so am i just wasting time with the carbs and its the valves????? or keep tinkering with the carbs?? im pulling my hair out and taking this piece of junk apart in my sleep!! granted i paid 500 bucks for it but im about ready to start a fire with it... thank god i have old faithful the 87 hurricane 600!!

 

Couple of questions first. How do you know the intake valve is leaking? Did you do a leak down test? Is this an F2 or F3? Backfire on deceleration could be lean setting on the pilots screws try 1/4 turn out. Heat related run issues could be air leaks, valve clearances, or R/R issues. Running better when cold makes is sound like the main could be too big. I have a similar jetting set up for just above sea level.

 

its a 94 f2. i took the carbs off when i got it home and spun the engine over and could clearly see air bubbles around the valves in cylinder 3. i just taped off 1/4 of the k&n. gonna take it to work tomorrow and see if it helps at all. and i changed the main from a 138 to a 126 i think it was. whatever the biggest one in dynojet stage 1 is

 

how do them carb boots look?

 

they dont look perfect but not too bad either. i taped off the k&n and it seems fine till i hit about 65 mph or so and it does it again

 

open up the pilots screws a 1/4 to 1/2 turn. If that doesn't cure it, raise the needles one or two notches.

 

ok when i feel like tearing it all down again i will, also almost seems like if i go through the gears beating on it it makes it run like that. sometimes its rides fine at 60 mph and ill get on it till about 90 and let off and after that it has that hesitation when im cruising

 

Getting to the carbs take about 15 minutes... You lazy lol

 

nah just sick of doing it over and over again lol. i just tried it earlier and it still is the same. i give up. ill just sell it at the beginning of next season

 

Haha lazy. I've dropped the motor 7 times before getting mine right.