[Uwon]

Must have been Mighty Mouse judging by the amount of insulation probably installed in an ill perceived effort to reduced engine compartment heat. Air cooled means lots and lots of air. Do a leak down test first to determine if you have a more serious problem. If it fails you probably have to consider a top end rebuild at the very least. If you get acceptable results, I would then pull the intake, shroud, etc and properly remove all that insulation crap. Check to see that the baffles are still there. Leak down test equip is $100 or so if you can't borrow one.
good luck.
Johan