My 2004 250ex recently had a breakdown. The engine starts fine and all (althogh it knocks) but when I pop it into gear and apply the throttle it just sits there making a fairly loud crunching noise coming from the engine. I have no idea what it is since we never really abused it.(clutch maybe?) If you guys have ever had a similar problem or might know what it is please reply, I don't want to take half the engine apart without knowing what to look for.

 

Eeeek! Sounds like transmission.

 

Welcome to the forums mikeman250 , first thing i would do is drain the crankcase oil and look for metal fragments/shavings this will give you a starting point on the damage ; i'm assuming your 250ex is a 4 stroke wet sump ( Engine and Trans share same oil for lubrication ) but if it's a 2 stroke drain the gear oil and look for the same !

williebee.............

 

WIlliebee is right. That is a good start without having to tear into it. I will add the oil filter on the check list. Pop it out and check it for shavings as well. May look like silver mush or graphite if you've seen it.

 

Sorry it took me so long to reply but, The problem has been solved. We sold the quad a couple of days ago as a fixer upper because when I started to look into it, it had more problems that I originaly thought it did.

once again, thank's for your help since I am not too mechanical with this kind of stuff.