run it then pull your spark plug out and see what color it is

if its white-ish you're lean

 

yes you must re-jet. its stupid to ride it at all before rejetting, if you keep it up you can caugh up some money for a bore and a new piston

 

just because you dont feel it doesnt mean it isnt lean, just saying that it wont idle shows that its lean! Dont wait untill its to late. my LT250R was jetted to lean and it ran awsome untill it melted a hole thru the piston.

 

I'm not denying it isnt running lean. I know it's running lean. I'm saying that I see that by it not idling correctly. I was just asking if it will do damage, obviously it will. How much $ are we talking for a new piston to be put in if something goes wrong with it. I just need to run it this weekend, then I'm taking it to the shop to get it jetted.

 

prolly bout 200 depending on if you damage the head any too. A jet only costs about 2 or 3 dollars and most dealers carry them. If you cant get one then you can have a machine shop or something drill out the one you have a bit to get you on the rich side so your fouling plugs instead of melting.

 

lean = more air less gas = burn up piston. Then u gotta get it fixed. Rich is better.. that way u just get new spark plugs. Get it jetted.

 

It's getting jetted....on monday, right after I ride it this weekend.

 

Thats nice. Have fun. We tried.
You never did say what the jetting is so were all assuming its stock with an aftermarket pipe. Guess if your too hard headed to take advice you gotta learn the hard way.

 

It's not that. I took the advice. I ordered an FMF jet kit from rocky mountain atv, it'll be here at the beginning of the week. Dont be so sensitive.

 

Besides, I called 2 Yamaha technicians at highly rated Yamaha dealers in the Ohio area and both said the risk is extremely minimal if I'm just running it on the weekend as long as I get it worked on next week. There's plenty of 15 year olds on this site giving advice that isnt exactly highly regarded. Besides, tell me who has ACTUALLY burned up a piston with the setup I have - stock everything with an FMF pipe.