Well did a leak down test today intake is leaking bad on the intake side. took the head off and sure enough it looks like a bunch of carbon buildup. I plan on lapping the valves. I think I might try to put it back together and see what I got. What do you guys think? Opt could you tell me what the torque specs are on the head and valve cover it is A4 stroke 90cc? I had my torque wrench set at 10 foot pounds and it broke them loose when I was taking it apart. Any problems with testing with the old headgasket?

 

Never reuse a head gasket as it can seep. Not sure if the 4 stroke Eton is similar to the Polaris 4 stroke models,but the head bolt torque was 11.5 foot pounds on these 90 models. You can probably google this to make sure. Just from being a mechanic no sense in guessing since you've got the head off. I'd pull the cylinder and replace the piston and rings. Plus you might look at this site for free manuals.ETON America

 

Bent intake valve looks to be the problem

 

Probably because the cam chain may have slipped time and valve may have hit the piston. I'd check the exhaust valve also,just roll it along the work bench and look at the stem for damage. Also see if the top of the piston has any marks.Either way looks like you got a little project going on.

 

I looked at exhaust valve but don't look bent. also you can see the bent valve when I took the spring off and spun it in my hand in the head, the exhaust looks to seat really good. I looked at the piston and it looks fine but I think I will order the parts I put a link to up in the thread and I guess I will order the valve from alpha sports oem parts unless someone else has an idea.

link to intake valve

http://www.alpha-sports.com/eton_parts.htm