I started on a old O.S. 40 in a Goldberg Eagle Kit about 12 years ago. (First Glow Trainer I owned) 2-stroke glow engines require less maintenance and burn less fuel depending on what brand, and they are not hard to adjust once you have a little knowledge and background about them. They have more torque than the 4-stroke, however they are dependable equal to the 2-stroke- if the adjustments are correct and the proper glow plug is used.





I still use 2-strokes in most of my closed cowl aircraft, because they don't really need much maintenance, and there's a less chance of damaging my cowl from taking it off and on the fuse.

My 4-strokes do have that great sound, and have more power in the top end being able to swing a bigger prop than a 2-stroke of that same range of size. The only down side is I have to check the valves every year- 6 months of continued weekend flying, and they consume more glow fuel. It's wise to run 4-strokes a little on the rich side. Most of the time my valve adjustments stay at their recommended settings, but I have had the exhaust valve adustment tighten up from the heat and vibration. So it's good to check them once or twice a year.

I like my 4-stroke engines, and I love to tinker so I prefer 4-strokes most of the time.

My favorite 4-strokes are O.S. and Saito, and I like them equally.
My favorite 2-stroke is O.S. hands down. I do own a Super Tigre .51 Ringed, but I had a bad carb and replaced it with a Perry Carb, and changed the stock muffler for a Mac. Now my cheap engine is as dependable as any O.S. I have ever had after doing that. The only thing I don't like about the engine is the clearence between the prop and carb venturi, and I have to get a special boot on the fixed venturi if I want to put on a special air filter.

The engine I've had nothing but troubles with was the cheap Evolution Glow Engines. They work fine after a few years, but tend to start leaking from the gaskets, the low end needle valve likes to move under vibration, and they don't seem to have the same power that O.S. does of a engine that size. Plus they seem to like a lot of air hitting the cooling fins and doesn't take the heat very well in a enclosed cowl. A O.S. engine seems to take the heat better.

FS 52 is = to a .40TS
FS 61 is = to a .46TS
FS 91 is = to a .61TS
FS120 is= to a .91TS
FS150 is= to a 1.20TS

Approximate conversions from 4-stroke to 2-stroke.


Pete