Hopefully someone has a suggestion that may help!! Have a 250x that starts right up on the first kick and runs like a champ! No smoke, awesome compression. Have adjusted the valves to .004 and checked timing! Everything is spot on.
But she has a knock that I can't figure out!
Is there something I'm missing??

 

use a long screwdriver and hold it to your ear then touch the other end to diferent parts of the engine....you'll be able to kinda pin point to where the knock it coming from, either the lower end which could be a rod,piston pin etc or the top end that could be worn out rockers or cam.

my 250x had cupped rockers that made a hell of a loud knocking/ticking, even though the valve clearences were spot on.

 

Thanks for the reply!
I've tried that with a long extension. It's definitely coming from the top(Rocker cover). Can't pin point if its the intake or exhaust. But I pulled the plug and there is an extreme amount of soot for only running for a minute or so(and it won't idle). So I'm going to clean the carb.
The other thing I noticed is that as I rev it a little the knock goes away. but the second I let off the knock is right back again. As if the timing chain could be slapping around and as I rev it up it gets more tension.

This is getting a now to be a bit frustrating!

 

hmm.....if it was me i'd pull the cam cover off and inspect the rockers and cam, you can also kinda see the timing chain so you should be able to poke at it and see if it is tight or not.

if you havn't already buy yourself a repair manual, it was the first thing i sent for when i bought my 250x.

 

Going to order a manual! But so far everything is intact

Thanks again

 

you can also take the tensioner off and stick a screw driver ware the tensioner was.
hold the tensioner against the chain slide firm.
turn motor on just enough to listen for knocking. i used the tech for awhile 8 outta 10 its timing chain

 

Thanks,
I'm going to try that. Haven't had time to mess with it since last message. But everyone I have spoke to about the problem has pointed to the tensioner or chain.
Will keep you posted
Thanks