I'm relatively new to glow engines, though I grew up on 2 stroke engines (snow-mobiles, dirt bikes etc.) What recommendations do you have for longest engine life and minimum problems with 2-stroke glow engines?? I recently purchased my first trainer (Hanger 9 Alpha trainer) with the Evolution .46 Which is broken in at the factory, and this engine so far runs excellently. I want to keep it that way and would welcome any tips you offer. One question is, should I drain the fuel tank after every session of flying? or is it o.k. to leave some fuel in the tank for a week or so? Thanks....

If ya want to keep it around awhile i would use the highest oil content I could get, say 18-20%castor will do the trick.

As for leaving the fuel in tank,I wouldnt do it, the fuel tends to draw water and will varnish (gumm) up the jets in the carb.
just my 2 cent's.

Drain the fuel and then restart the engine to get the remaining fuel out.

Alcohol attracts moisture and will rust the bearings.

I would suggest you use after-run oil if the engine will not be used for a few days.

Welcome to the hobbie Flint Lock 28,

I agree with both suggestions. Pump the fuel tank dry and run the engine until all the fuel has been burned out of the system. Then take the glow plug out and place a drops of after run engine oil in the cylinder and turn the prop over a few times. Would not hurt to place some after run engine oil in the carburetor also.

Youll get many answers on this one.

i use fuel with 20% castor and never bother to much about a bit of fuel in the tank (i normaly fly till dead stick on my last tank of the day) i run my engines about once a month wheather i fly or not.

if i was storing them for an extended period say 3 months plus, i'd drop some sewing machine oil down the carby and down the glow plug hole and turn it over by hand a few times.

Thanks for the tips fellow flyers, I will put them to use....I plan on flying once or twice a week, so I'll drain the tank after each time out. By the way, I'm using SIG 15 % nitro, 20 % oil, (half castor and half synthetic) is this a quality fuel?? The old gentleman at the hobby shop I buy from, recommends this fuel that he says has a good track record. Thanks.

Good choice on fuel/oil content (I think) . I use Auto Transmission fluid for after run/storage, tip the nose up and rotate the prop as well as down doing the same, this covers the bearings fully. Drain the tank each time and join both the pressure line and fuel line between them with a piece of tubing, this seals the tank from everything including moisture and evaporation of the light ends of the remaining fuel(always some lift in the tank).

Marvel Mystery Oil is also an excelent after run oil and very cheap.

I believe the concensus on RCU is...

MMATO Marvel Mystery air tool oil - YEA :thumbup:
MMO Marvel mystery oil - NAY :thumbdown

Saw 8 responses. All OK. However IMO and experiences I don't baby model airplane engines. I squirt some oil in one destined for storage and pitch it in the drawers (file cabinets and small chest-of-drawers). I had well over a 100 by last count a few years ago.
If I want to use one, I simply take it out and wash throughly with either wood alcohol, or rubbing alcohol depending on what's in reach or if engine is badly gummed up. May even remove backplate, etc. but get it fairly clean, oil it up with some machine oil/whatever is handy, and get it back together. I have many times picked out an engine that may have been in the drawer for well over 10 years and up to over 20 years, cleaned it up, set it in an airplane, choked it a few times, turn the prop over by hand several times, felt the *bump* and one flip has it running.
If you wish to really protect your engine, the best thing to do is use a fuel filter between the tank and carb, (catches that garbage the muffler feeds back into the tank) and to set needle for at least 700 RPM BELOW (Old sport engines I use 1000) the peak ground RPM. In addition use a suitable size prop. Not too small or too big. Too small simply over-revs. and too large lugs the engine at a low RPM that prevents adequate cooling fuel mixture to circulate through the crankcase.
After flying connect the fuel feed line to the tank overflow line. You can stop any leaks on the floor that way, and your muffler/engine does not get a case full of fuel should you point the nose down
Do empty the tank after a day's flying. The fuel will eventually corrode the brass tank lines. Oil congealing in the tank, in the carb, or engine crankcase can give you a fit for the first flight of the day. If you then start making big changes, well, the fits continue.
Don't worry about the engine too much except during the flying lean/rich/prop thing. You can easily wind up stomping pixx ants while the elephants thunder over your bod.!

you can use Automatic transmission fluid for after-run oil, too. When you use after run oil, use more than a few drops, it takes at least a good tablesppon of oil to get the oil into all of the parts of the engine.

I am kind of curious as to why no one uses OMC fogging oil when they know the 2-cycle will be shut down for a while? I always run out the last of my fuel in any of my 2 cycles and then fog it while it dies...

I'm surprised no one mentioned this, but the ONE most important rule to preserving any of these engines is to NEVER let it run lean.

I have a lot of 2 strokes, usually run the engine dry at the end of the day (not always), sometimes use after run oil. But I always run them on the rich side and they all still run flawlessly.
Dennis-