yzf 400 carb hesitation

[frig]

I own a 1999 yzf 400 low hours looking for some info about low end carb hesitation or a dead spot int the

beginning of throttle, bike runs strong mid to high in talking to other riders sounds

like it always been a problem. I installed a hot shot from boysen and didn't notice a big difference. wondering about jetting pilot circuit? Is that were the

problems lye??

[One Louder]

0 to 1/4 throttle is affected by the fuel screw and the pilot jet. Have you cleaned the carb good? do you have an extended fuel screw? these are very touchy and the fuel screw will need frequent adjustments

BTW welcome to TT ?

[eddiev]

I have a 99 also and I think spending time with the jetting helps a lot and I bolted on a part called a P38 from Factory R&D. It helped even more!!!

Good Luck!!

[ryan c]

Clean yor accelerator pump on your carb its simple, and its your soulotion to yor problem

[frig]

Yes, cleaned carb, what is a P38 and where do yoou purchase

[ben_suhard]

I own a 1999 yzf 400 low hours looking for some info about low end carb hesitation or a dead spot int the

beginning of throttle

Even when the bike is jetted properly, you'll still get a bit of hesitation when opening the throttle quickly because with four-strokes, the engine doesn't produce as much vacuum as a two-stroke at low revs. One trick is to turn the idle up a bit so that the engine is creating more vacuum.