Apollo 250 Lost compression
 

So I just changed the oil at 300 miles and after doing so I started it and it started just fine. I let it warm up and then hopped on to see how it ran with fresh oil. After 10 seconds it shut off and began to click in the motor. I tore it down and opened the valve covers to see that the exhaust valve was opening a 1/4 inch. After tightening it back down I still have very low compression. Any suggestions on what I can try and does anyone have any links for a gasket set for it. The full name is the Apollo DB-36 250RX

sorry to hear of the issue you're having....probably for better help here on the forum,..we may need clarification on what you mean "exhaust valve was opening a 1/4 inch. After tightening it back down...."

1/4” gap I suspect.

Sounds like it ingested something. Pull the plug and have a look inside.

Does that use the CB style (OHC) engine, or our CG (OHV) engine?