2000 Yamaha warrior.
Blows some smoke at startup and under hard accel. Could be worn piston rings or valve seats, yes.

My question is mabey it's related to the way it runs. This thing feels like it does not have alot of power. At higher RPM, there is nothing.

It's stock front to back. I am an auto mechanic, and it feels rich to me. The jetting is stock.

I removed the carb, and saw that it doesn't have a moveable circlip to change the needle position. What is the easiest way to lean this thing up so I can see if it makes a difference? Also, do these things come with rich jetting from the factory? Thanks

 

What color is the smoke...?

 

Your jetting shouldnt be that rich from the factory, although i think pretty much all Yamaha 4 strokes are set up a little rich to start with. Check your float level. Bosch

 

smoke is a little blue

Plug gets black..
everything is stock.

I

 

Could be your rings. Blue smoke is usually oil,,,that would explain your lack of power.

 

If it’s blue when you start it up after sitting its def the rings > Oil has time to seep through. A glossy black plug also indicates oil, a more dull black plug means its running rich. I guarantee when you pull your top end you will find a small puddle of oil on top of your piston [img]i/expressions/face-icon-small-smile.gif[/img]

You're a mechanic...?

*TIME FOR A REBUILD!!

 

Former auto mechanic, not ATV (current instructor)

My real question was really about the fact that I could not change needle position, and if their was a common trend to replace jetting in new machines.

Mabey I just didn't ask the right way.

 

Ehhh I don’t even remember if my stock needle did or not lol but the Dyno Jet kit has the needle and clip for the job. If she’s blowing blue you need to rebuild regardless - Shattering pistons = BAD. There is no point on even to try and jet her if the rings are worn its going to be wrong.