ok, let me start off by telling you what i have on my 03 z400. I have the alba jet kit, alba slip on pipe, k&n filter with outerwear and no airbox lid. I recently geared down to 13:41 to get better acceleration. Well, my problem is that whenever i open up the throttle all the way it starts to cut out. IT sounds like its hitting the rev limmiter, but im not sure. I think it might not be getting enough air, or not enough fuel, i dont know how to tell, also, it might have some back pressure. These are just some of my thoughts. I really need some help to get my z running better. Any help is wanted. If you need to know more to help then just ask. Any help at all is wanted.

 

if you geared down...chances are it is the rev limiter...check your plugs

 

Did it cut out before you geared down?

If not you are probaly hitting the rev limiter.

 

no, it didn't, thats why, even though it soundeld like bad jetting, that maybe my rev limiter was stoping me, the weird thing is that my dads quad is the same as mine, except he has a yoshi exhaust and a 150 main jet, he geared down and his is running great, why wouldn't his hit the rev limmiter too.

 

i would think it was the plugs too

 

My friend had his 300ex jetted too high and it cut out at higher RPM's, your could be doing the same.