I could not figure out why my G-38 was acting up when it always ran perfect!!! Had a dead stick and it woud not start. I pulled the cowl off and was checking the fuel lines. I then noticed the plug in the crank case was missing. It looks like 10mm is it pipe thread. I have a 10mm bolt in iot right now but I did not want to over tighten it. Can I get a plug any where that will fit it. Lucky find and a nice safe dead stick1

Is it in the top of the crankcase or the bottom?
If it is in the top - maybe you are missing a sparkplug

Ok - sorry, I have no idea what the actual thread is.

Some pictures would help

Maybe it is the option takeoff for a pulse tap for smoke or another type of carb. losing it would cause your cylinder base pressure to go away and thus no transfer of fuel/air mix to the piston top. Perhaps the G-38 parts breakdown schematic will give you the thread of the plug.

Regards, Richard

http://www.horizonhobby.com/Products...D=ZEN312013510 $4.95 case plug

There's a gasket that goes under it http://www.horizonhobby.com/Products...D=ZEN313013520 $.99

In the second picture, you can see where it goes

Plug it off with anything that will thread in good. Use some sealer or loctite. Capt,n

I think it is just regular 10mm

W8ye is right on with what you need.

Insure that the bolt is not so long that it interferes with the crankshaft counterweight. Use locking and sealing compound as others have said.

Or, get a smoke kit and make smoke!

Regards, Richard