Predator 212 No Compression after new head gasket

[IdahoKartGuy1993]

Yesterday I got my new P-212 head gasket in the mail. I immediately noticed that is was considerably thicker than the thin metal OEM gasket. It is also not made of metal, but some fiberglass-like material that sandwiched the thin metal gasket. Anyway I took the head off, took the valves and rockers apart and cleaned them, re tightened them, and put the engine back together. After the engine was fully reassembled with the new head gasket and spark plug installed, I go to pull the cord, and there is virtually no resistance! Normally you can feel resistance, but I pulled and pulled and it wouldn't start. I could hear the piston moving. Could it be that the new head gasket is too thick and porous?

 

[bob58o]

I'd start by setting the valve lash. If not correct, the valves may not close properly. No valve closey. No Compressy. If you were running a 0.010" gasket and now running a 0.040" gasket, you've given up some compression. Normally going from a 0.043" gasket to a 0.010" gasket will take compression from about 8.5 :1 to 9.5 :1. (assuming 212 with 22cc chamber)

 

[IdahoKartGuy1993]

So... basically I need to order a new gasket that is the same size as the OEM one? And I cleaned the valves, they actually close better now than before with all the black soot buildup

 

[Karttekk]

Before you do anything, squirt a pump or two of motor oil in the cylinder through the spark plug hole to seal the rings then try again. Sometimes that will seal up the combustion chamber to give it enough compression. Worth a shot.

Thanks

 

[IdahoKartGuy1993]

I will do that and post results to this thread for all the others seeking guidance on this issue Thanks!

 

[bob58o]

You don't need to get the thin gasket. That isn't the issue. Well it will cost you some compression in a world where we are all trying to gain compression, but you have another issue. I don't care how clean the valves are, if you didn't set lash correctly - they may not close. Since you seemed to dismiss the most important part of the post....

START BY SETTING THE VALVE LASH WHEN THE PISTON IS AT TOP DEAD CENTER (AS IT TRANSITIONS FROM THE COMPRESSION STROKE TO THE POWER STROKE).

 

[Karttekk]

Taken from another Internet posting. Two simple things to try. Good luck!

"Adding a bit of oil through the spark plug hole allows the ring to wall seal
to be restored and compression comes up. It is a good idea to check to check the
rocker arm clearances via a valve adjustment also."