BRAND NEW engine, sounds like a blender!!

[wolframore]

We did a second gasket and lost 40 psi compression. You can check the piston clearance with a piece of solder. Plasticine clay is what I was taught but a piece of solder stuck in the spark plug hole works. Check when the engine is cold.

Didnt you say its a new engine?

 

[lazar26]

Shouldn’t lose if it was an extra gasket under the jug would it?

move never heard of that before, I’ll have to look that up. But yes, engine was brand new with the tap. Has maybe 10 miles on it now, ran it twice. Once the engine warms up, most of the tap goes away from what I’ve noticed.

 

[wolframore]

Under the jug it changes timing and loses compression. I had a similar noise once and it was little chunks of aluminum that broke loose. I’ve fixed it with JB weld but haven’t run that one yet, it got ported and windowed and getting a reed now. I might take it back apart to stuff it and balance the crank.