Hello,

I have an Irvine .39 bought in 2005. The engine runs fine, and it has had only 10 flights on it. From new the engine has had little resistance to turning over TDC.

What puzzles me is that it is so different from two Irvine .53s I have. Both these engines were very tight when new (and they still are a little tight after nearly 100 flights).

I have noticed that the .39 needs to cool down a bit after running to get good compression again.

My Irvines are all ABC engines. Can anyone tell me what is to be considered as ‘normal’ or acceptable in this instance? Can I expect a normal running life from my .39?

Thanks,
Helge.