I have a Ryobi 31cc I converted myself. I am running the gas glow conversion. The problem I'm having is that has backfired more than once when starting & when it does the prop, adaptor, &flywheel come flying off. It's pretty scary when it happens.What's the best way to secure everything? Is Loctite enough or would some type of set-screw be better. Any help would be appreciated.

I uus a starter and to tighten the prop I use a pice of rope in the spark plug hole and turn it in the dircetion you want to tighten the prop nut ive not had one back fire on me but it could happen michael

Check your timing, probably too far advanced. May need your starter for the first few starts.

I have a Mac 28 that I raised the compression too high on it and it backfired,
predetonated, threw props, etc. I put a . 005 soft aluminum gasket back under
the jug and that cured it. Glow and E-85 fuel.
Jack

I got my engine from harbour freight. It is the two ring version plus it has Bowman rings installed on it. I'm using the Hangar Nine adaptor with an OS 4stroke glow plug. Fuel is one part Methanol with two parts gas with Klotz oil.

Try a lower percent of nitro.
That should stop the kick back you are experiencing.

1/4" cotton rope in the spark plug hole with the piston all the way down works great for tightening.

Lock tight will usually be all you'll need. I have heard of people using epoxy.

An electric started would also stop the kick back, but lower nitro should do the trick.

I use blue Loctite on all my prop hubs, and never have had one come off. Some of the suppliers recommend using JB Weld, but I don't think that is necessary. I am a little confused as to why you are running a flywheel when using Gas/Glow? When there is enough shaft sticking out, I make my prop hubs so that they extend back over the straight part of the crankshaft, and use a couple of set screws for extra security, but I have several engines that don't have this feature and they work without problems.

Also, too much choking can make them backfire sometimes.

AV8TOR

I left the flywheel unmodified until I was sure I was happy with the performance of the gas glow conversion.