Last week my cousin took his warrior out for its first ride, he just bought a used 01. It rode great for the first three or four hours and then it started making a nasty nocking noise. We pulled it out today and my first hunch was the valve rocker arm, and sure enough the nut holding the rocker on top of the spring was missing on the intake. Now since it was used I dont know if this was missing from the start and not replaced or if it was on and just came off.

So if it was on and then came off where could it be(we used a magnet and could not find anything). Could it work its way into the cylender? Could we have caused any damage. We are ordering the nut today for the replacement. Any help would help

Aaron

Did you pull the spark plug and try to look in there to see if it might have beat the top of the piston to s***?
It got to be around somewhere,as it wouldnt have ran without the valve following the cam(opening and closing0 kinda hard to do...
One thing is you have to find it..take it apart peice by peice till you find something ,its there somewhere..
Something for thought some nuts are not magnetic,,,,
For damage ya the valve could have hit the top of the piston,bent valve eff*ed up piston!that sort of thing...good luck!

we tightened the adjuster back and started the bike to see if that really was the problem, and the bike started and sounded fine, no knocking or slap of any kind. Im thinking that the nut may not have been there from the start as the bike was bought used and I cant attest to the condition. I have talked to some people on another site and one said the nut cannot work its way into the engine and another says yes it can. I am waiting to talk to someone from kenz about wether or not it could have gone down.

Aaron

it would not have run for 3-4 hrs before the problem,,,if you know anything about cams and valve trains you would know this,,call Ken and talk to him he's a good shop..
he built my YFZ

heres Ken website and where his guys hang out at.
http://atvfanatics.com/eve/ubb.x/a/frm/f/8756030102

It might be possiable that it went out the exhaust ,but i dont know
Aaron post up what you find out ....see what ken says...Thanks

I called kenz earlier as they were the only place in town who actually has the nut available. My cousin is using a magnet to see if he can find anything in the piston, he is also draining the fluids out of the bike to see if he can hear a tap tap when shaking the bike. We are hoping that it was not replaced when the previous owner had done his last service. Dunedevil I looked at the valve train and the valve tension screw could have operated for some time with with the ticking getting progressively worse. When he started the bike again after readjusting the valve tensioner without the nut the engine sounded great, no noise what so ever. Im pretty sure that if the nut was in the cylender it would have made quite a commotion. Im more concerned that it worked its way down the timing chain into the case. We will see

Aaron

man that sucks,,hope its an easy get to ...