I think I read long time ago something about which plug to use in an inverted mounting of a 2 stroke engine. What shoul I use? I have an OS # 8 and the engine is not completely inverted it is more like 8 o'clok mounting. How does it affect the performance?

Please advise; Thanks.

The #8 should do fine in an 8 o'clock mount. When fully inverted some people will use a plug with an idle bar or a hotter plug like an A3. The problem is that the cold fuel can settle down/spray down on the plug coil when fully inverted and cool the plug element. A higher idle speed also helps but most don't like to go this route.

So it is not much of a deal. Thanks for your help.

The "fuel deal" is where your tank is mounted in relation to your car on an inverted engine. If you mounted your engine inverted an installed the tank in its stock position, chanes are your tank is much higher than the carb line and it does not matter what plug you use, you will have problems

Oh! the plane was designed like that so I think I should not have problems with the positioning of the tank, but that is a very valid quote to keep in mind for a build.

Thanks!