my friend has a 2004 Warrior that's all stock yet and he first took the baffle out of his pipe. now he cut 3/4 of his pipe off so there is only like a 2 1/2 piece of silencer left on it. i know about doing this to 2 strokes or with aftermarket silencers, but i never thought it was a good idea to cut almost all of the silencer off. will this burn his rings or will it be ok.

 

It may burn his rings, it will definitely burn his valves. It may also burn the top of the piston.

I am surprised it even runs.

 

Little paranoid arent you? I doubt it will do anything except sap power and annoy people. Im not 100% sure on how to judge what is enough pipe but ive been told its too short when oxygen can get sucked back into it and make it to the head to burn stuff.

 

If that was an improvement, ya think the factory would have done that?
when i was a kid i screwed with things like that...a wannabe engineer...

 

thanks guys it not that i really care cause it's his own fault if he messes it up i was just curious cause he's pretty dumb on quads and he thinks you can do stuff like that to them and it won't hurt anything. i'm not an expert on 4 strokes, but i know just about everything there is to know about 2 strokes cause it's what i ride and race.

 

Fact 1:
4-strokes require a certain amount of backpressure in the exhaust. Without such
backpressure, the heat from combustion rushes out the valve faster than designed
and burns valves, at the minumum.

Fact 2:
Without minumum backpressure, the air flow rate thru the engine is greater than design,
causing a very lean mixture, increasing the heat of combustion, aggravating the valve burning,
with the possibility of burning, even melting, the top of the piston, frying the the top ring, and
scorching the upper cylinder wall.

Not paranoia, just physics.

 

I was waiting for someone to bring up the lean mixture part, If he re jetted he may be alright for a little while.

 

Bad.

 

Explain to your friend he is losing a lot of power.

 

Woods Runner is 100% right on. Rings,valves,pistonand cyl walls will all get burned to hell!!!!!!!!!. 4-strokes need Backpressure Your buddy is riding a hand grenade . get a dennis kirk book and get a DG or a Cobra pipe(rear section)delivered to your door for about $100. if not bring a tow strap.hope this helps,Dave