Well my son made a bad mistake. He dumped the oil and filled the trans and of course drove it with no oil in the crank case. still runs great but there is a top end noise seems like it from the lifters. Any suggestions would be great.

 

Wow, how long did he ride it with no oil?
Probably fried the cam and cam bearings, rings, piston, valve quides and I'm surprised he didn't fry the bottom end. I wouldn't be surprised if he did do damage to the bottom and it just hasn't reared it's head yet.
Time to tear the top end apart and take a look. Good luck.

 

how can it be making noises and be running great at the same time? im curious too - how long and how hard was it ridden before this was discovered?

 

believenit or not, i filled the crank case with oil, left the tranny over filled, and still runs great. I think i dodged a bullet here. I am going to lokk at the t-chain tensioner and the lifters. I think the crank bearings are fine.

 

Can you take a minute to answer some questions:

What year????

How far and how fast did he ride it????

Just for the record, what kind of oil were you using????

Did you know that it is highly recommended that you run extra oil in the trans anyway (~100 cc's).


There was a guy in here a few years ago who had the dealer change his oil (250EX). Of course, the dealer forgot to refill it. His kid rode it half a day before it seized up. Not quite the same engine, but still.........

 

I wouldn't doubt that you did damage and it just hasn't shown itself yet.
You more than likely will have premature engine failure.