Valves hitting the pistion..?

[vartiak15]

So I took the head off my act 90 and there are valve marks on the piston. Is this caused for too big of a cam? Or do I have something off far as valve adjustment, because I checked the clearance on the valve tappets.

[tri again]

Did it ever run that you know of?

Cam chain could be stretched but not sure the timing
would allow it to run if it was that far off.

Someone adjusted the valves in the wrong position and had them waaaay too tight.
in the wrong piston position.

I've heard that crank bearings can slop just enough the let the piston hit the valves.

I happen to have a couple bent valves from a 90 so I know it can happen
unless the box of parts got dropped and bent both valves?

Is the top of the piston all fuzzy with 1/4 inch of carbon?

[El Camexican]

Timing chain off by a tooth?

[kasey200x]

You need to provide more info on the engine. Does it run? Any major engine work/changes lately?

[vartiak15]

I built motor from scratch with the sl90 manual clutch kit, no hi lo box, 55mm rocky piston, new valves n springs, and now I took out the head and swapped in a helm n son cam. I'm going to line up timing again tomr and see if I can get it to run! Any tips when lining up the timing?.

[Scootertrash]

I built motor from scratch with the sl90 manual clutch kit, no hi lo box, 55mm rocky piston, new valves n springs, and now I took out the head and swapped in a helm n son cam. I'm going to line up timing again tomr and see if I can get it to run! Any tips when lining up the timing?.

maybe download a manual with all the important information in it??:

http://www.oscarmayer.net/atc/manuals/

[oscarmayer]

^ thank you sir, i was just gonna tell him link is in my sig. ;)

[vartiak15]

Wow my manual sucks compared to that one, mine said nothing about the centerline thanks a bunch now I just need gas to get to the plug and she should run

[Scootertrash]

^ thank you sir, i was just gonna tell him link is in my sig. ;)

No Problem. It's an excellent link.

Every time I see your posts that damn song pops into my head:


http://www.youtube.com/watch?v=aNddW2xmZp8