Hi Guys
I have an OS 120 Four Stroke that my buddy gave. The engine has a timing type of a metal ring with a hall sensor pickup installed behind the prop washer. All it needs to be converted to gas (Other than EI) is a spark plug that supposedly fits the hole for glow plug. I have been told that there are special spark plugs made to fit this application.

I would appreciate any help in finding the spark plug that fits the glow plug threads/ opening the cylinder head (if there is indeed such a spark plug). Also if any hints tips to make this engine work on gas.
Thanks in advance.
Asim

They do exist, I had one but I sold that unit so I can't tell you the #. I would check with CH Ignitions, that's where mine came from.

J

I think this is what you are looking for, they will thread right into a glowplug hole.

http://sparkplugs.morrisonandmarvin.com/

call C&H they have them, I mormally keep 3-4 extra but you will need a plug boot to fit also, they have those too.

Thanks for the info guys. I tried calling the Rimfire people yesterday but no luck. Will try C&H today. Also found a video on youtube of a guy using these plugs on an OS 120. He used methanol with no nitro. Maybe C&H people will shed some light on gas conversions and what to expect. Thanks again.

here is what I do with them

Here's a conversion I did not too long ago.

[link=http://www.dieselrc.com/project1.html]FS-52 on spark ignition.[/link]

This engine has the old NGK plug in it, but I have Rimfire plugs for the next conversions. I ordered from Rimfire online and got the parts 3 days later.

If you need a CD unit, this is the best deal I found. $93 shipped with the CDI unit already set up for the 1/4-32 plug, Hall sensor assembly, switch and spark plug.

http://www.syssaaircraft.com/gas_engine_ignitions.html

I installed it on a Saito 100 and couldn't be happier. Unless you're going to change the carb I'd stay with methanol....carbs designed for glow fuel don't meter gas very well.

The good thing is that you don't really need nitro and can get by with 6-7% oil. You can buy a few gallons of methanol and use it to dilute commercial glow fuel until you get the ratio you want. If you have dragstrip in your area you can probably get some there. If you just want to try a little the gas line antifreeze "Heet" and the generic equivalents thereof are methanol.

Rick

Thanks for the info guys. I'm glad I posted the question, learned alot from the leads and am encouraged to experiment more with the idea. Ideally, I would like to run this engine on gas but dont want to change the carb. I'll take some pics of the actual engine I have and post em in the forum. It has a disk near the prop washer which I think I should remove for the ignition system.

Rick, I like the ignition system you recommended. Seems more complete and geared towards what I want to do. I'll try to call them morrow. Thanks again for all the help.
Asim

Hellow Ken.....keep up the good work!!! Capt,n