jimo811

My Feedback: (17)

What would cause a 30 size engine to lose compression in the middle of running. I am pretty sure that it was not too lean. I am running 15% cool power fuel in it, and it was running good enough to fly 2 days ago. Thanks for any help you could give.

RCAdd1ct

Check your clunk line it may have colapsed.

jimo811

My Feedback: (17)

I wouldn't think that a colasped clunk line would cause the engine compression to go away? There is still no compression even after it was off. Engine will not start.

adrian-RCU

check your head bolts but it sounds like lean running has killed this one

RCAdd1ct

I had a heli that the clunk line colapsed and the engine leaned out enough to sieze the motor before I could get it on the ground. It messed the sleeve up and thus the loss of compression.

I would hate for you to get the engine fixed and have the clunk line ruin another.

Culverson

My Feedback: (14)

If it is a ringed version some have lower compression on start-up to counter starting issues like seen on some ABC larger engine which can be rough on your starter shafts. But it sounds like you need to check-re-torque all engine bolts especially head bolts and go from there. If it really seems to have a loss of compression you might need to tear-down and check the ring in F series and if ringed version of newer OS, or if ABC which most are on newer engines look at the piston & sleeve to look for damage or wear and check to see if you need a piston or liner or ring..according to if it's ringed or ABC type engine..

This is after you exhaust all other issues addressed here first..

jimo811

My Feedback: (17)

Upon taking this engine apart to see what was wrong, I found that the ring had broken. Killed the piston, ring and rod. To replace these parts will cost about $70, so it looks like I will be purchasing a new engine. Cylinder was ok, believe it or not. Anyone have an engine that they want to sell me resonable. LOL

Thanks for the input.