ORIGINAL: MKnutson
The brown truck stopped by and had the engine!
First off I can say it looks typical OS perfect casting, and it's a little lighter than my NGH38.
Overall a very nice looking engine.
It has unbelievable compression just out of the box.
A decent baffled muffler comes with it, which is good for our field.
Only a couple of gripes that I can see are (1), it comes with an RCexl made in china plug, cm-6 type.
And (2), the prop shaft is a little small for this size engine, I have to make an adapter bushing to fit any of the props that this engine will use.
These size props all come with a 10mm hole and the shaft threads are 5/16 or appox. 8mm.
Other than those two small issues, she's a sweet engine!
Mark.
Sounds like the engine uses the standard 8mm shaft size, same as on their 33cc 2 stroke. APC has that hub size standard on their props. APC has recentlyreleased several props intended for the YS170 and 175 glow alky engines. These should work well on the OS40cc, (I think)