Originally Posted by
JRgraham
Ive had quite a few YS engines too, always ran flawless for me until my Dad got the 110. It would dead stick on him until finally the firewall broke off the plane last dead stick landing. He had even sent it in to YS and received it back claiming perfectly fine. I took it over from him, fixed the plane and went on with it.. ran great for about 5 tanks, and started running erratic and dead sticking again.. I found that the gaskets were getting eaten up somehow, no matter what I did. they are nearly just paper as it is.. I rebuilt it 3 times with new gaskets, same scenario.. about 5 tanks and problems started with gaskets leaking being eaten away.
I still have it in pieces, but unless I find a better quality gasket set.. it will remain in pieces.. its too bad for that one, because I have always had flawless running YS motors otherwise. Maybe just something out of play with that one causing extra vibes that eat the gaskets.. I dont know.
That's a tough one, I'd expect the gaskets are the victim and not the cause. Gaskets tend to die if the clamping pressure is incorrect or uneven, or if they are lubricated before they are installed.
Two things to check would be are the mating surfaces flat? and is everything dry when you assemble it? I wipe all my surfaces with methanol or isopropyl alcohol to make sure they are lubricant free. Considering this engine has done this from new and from a factory rebuild I'd be really tempted to bet on uneven mating surfaces.
After a full rebuild I do tend to pull the engine after a handfull of flights and nip things up once the gaskets settle but I can't remember anything ever really needing tightening up. Valve cover is a bit hit and miss though, I'm tempted to pull the gasket on that, use a sealant as it only ever comes off about 2-3 times a year..