I ride a 01 Warrior

Ever since I got it, I noticed it stutters in the high rpms. Even after the motor is fully warmed up, and after throwing in a new oem spark plug and UNI air filter.

I always thought it was just something in the carb. So recently when installing my hmf slip-on pipe and jet (147.5), I cleaned the carb out real well. The quad still stutters at high rpms. Only high rpms, even before I hit the limiter.

Here is what I narrowed the problems down to...

1) Bad ignition (need new plug wire, new type of plug)
2) Fuel type (I've been running 87, maybe 91 will do the trick)
3) Clogged Fuel Filter? (quad came with one custom installed right after the fuel valve)
4) Air intake problem (Have brand new UNI filter, perhaps a proflow kit with holes in the lid)

Anyone with any advice? Anyone else had this problem? Thanks for the help

 

I dont have any advice but my yfz450 keeps doing the same thing

 

Based on my experience:

1) bad gas
2) bad spark plug
or
3) wrong jetting

 

How about a poor connection between the spark plug cap and the plug?

 

Sounds like jetting but could be other things too.

If you pull the choke on slowly while its doing the sputtering...does it get better..worse?

 

you should probubly up shift....just kidding, that was just the first thing that came to mind...maybe the jets are wrong. better yet, could just be cause its a four stroke and thats what they sometimes enjoy doing. crap gas is a good one too...empty ur gas tank and refill it...clean the air filter too

 

That is very possible .I have had that same thing happen on my 690.