Hi , my names Troy and I am new to this board . I am trying to fix the neighbor kid warrior . He was riding and it stopped running , and now it doesn't start . Fuel,spark but no compression . I put my thumb over the plug hole and nothing . The timing is correct, the piston is moving up/down ( ruled out 1 way starter bearing) so I started checking valves. The intake side is good , clearance is .004 and rocker is loose that you can wiggle it up/down at TDC to feel the clearance . The exhaust is my prob , the rocker is so tight that it actually will not allow the valve to close. If I back the adjust all the way back and make a complete stroke the rocker ARM is tight against the spring . If I take a screw driver I can slide it in and twist the ARM to go back to its starting point, but it is tight . I assume no compression is because the exhaust valve is open . Thanks for any help I receive. Troy

 

Welcome.

Something is broken bad in that motor. Could be a lot of things but my guess is a sucked valve or the seat broke and now the valve is sitting way higher than it should in the head.

Bottom line is, if it's as you say, the head has to come off.

 

Thanks for the reply, I wanted to ask if maybe the rocker arm and rocker shaft are bad due to lack of oil . It's a 2000 that looks like it was ridden hard. I was thinking of removing the cam sprocket and a head bolt and pull the rocker shaft out and just replace that and the rocker . No ghost deed ever goes unpunished , I thought I could help the kid save a few bucks and now its a remove the head and valves etc..... Thanks I guess I can call him over and we can do it together .

 

If the adjuster is backed all the way out and you still have no adjustment it won't be the shaft causing it.

You're sure it's on TDC on the power stroke right?

Let us know what you find.

 

Well I removed the head and the problem is the rocker arm is seized on the rocker arm shaft . What was happening was the shaft was rotating up/down because of the stuck rocker . So I removed the head and used a 6mm nut and threaded thru a steel plate to "draw" the shaft out . Every 1/8 I would back it out and add a washer making sure I kept as much threaded material making contact . Went thru a couple nuts because the were stripping slightly and I didn't want to take any chances. The shaft is gouged and the inside the rocker has a lump of metal imbeded . It's about 1/8" away from the oil hole . It's poss it just wore over time with lack of oil ?? A new rocker/ shaft , head gasket etc... And the kid can have it back . Thanks .

 

Forgot to mention piston and valves look good . No marks and very little carbon.

 

I don't really see what you are saying? What do you mean the shaft was rotating up/down? How far was the shaft worn? With that much wear I would think the shaft was almost worn in two?

Anyway I'm glad you found the problem and will have it running soon!

 

I'll try to explain. The rocker arm rotates up and down on the rocker shaft . There is a hole in the rocker arm that allows oil to lube this shaft. The shaft is a few thousands of a inch smaller then the inside diameter of the rocker . The rocker shaft also sits in the head. Supported on both ends but its not ment to move , its more of a pressed fit . Now in my case the rocker seized on the shaft . That made the shaft rotate up/down as the valve would PUSH it up and the CAM would force it down . When you set valve lash, say .007 you can grab the rocker arm and wiggle it up and down making it tick,tick,tick. Well my intake would but the exhaust wouldn't budge . Wish I could post a picture here to show the shaft was scored .

 

Sounds like you should have it back together in no time. Let us know how it runs after it's back together.

 

Replaced the rocker and shaft and put head back on and it fires right up . My problem is I don't get any oil from the small bolt in the head . I let it run for a minute and nothing . I checked and the filter is in the right way , the "open" part goes in first and the closed side faces out . Iam sure lack of oil to the head started this mess in the first . Any ideas to check would be great . Thanks