I asked this question in another forum at the end of a long thread and figured it'd get more exposure in here.

I purchased a brand new OS AX .46 for my LT-40. We ran it rich during break in and it ran great. Flew 11 flights. At the end of the last, I pulled the fuel line and let it run down. I then let it drain for a bit. I emptied the fuel tank, closed the throttle all the way and plugged up the exhaust outlet with a cap.

Fast forward 3.5 years and its been sitting inside the airconditioning at my house, out of the elements for all this time. I never put any afterun oil in it or any such measure.

My plan is to just replace the fuel tubing, and fire it up in a few days and run a tank through it. Should I do anything else to it? I know some would recommend pulling it apart and replacing gaskets, but is this really needed after only 3 years and change of sitting inside a climate controlled environment?

I figure a good run on a rich fuel setting for 20 minutes would clean it out and lube it up nicely. I plan to start flying the airplane again in the spring.

As long as the engine didn't gum up from sitting for so long you should be fine. I would imagine it will fire right up and run. I've had OS engines sit longer than than and they started up with no problems.

Ken

If the throttle is not stuck and the piston turns over freely I would just fuel it up and start it. Maybe run it rich like you said for a tank or two. But if it was running good I probably wouldn't even do that. It will run a lot better once you get a gallon or two of fuel through it. These are very nice engines.

Given your particular cicumstances as the others I see no problem in just fueling and go.

One issue that sometimes occurs and thats a long shot has nothing to do with the engine. If you are using a conventional fuel tank over a protracted dry storage period the rubber bung stopper can become hardened and present some leakage problems either just pressure and or liquid.

This is not a worry if you have a Hayes 'O' ring type tank.

John

My .46FX sat in the garage for 10 years before I used it again in January 2009. It was gummed up inside. I removed the glow plug and filled the cylinder and carb with fuel and let it sit overnight. The next morning, I drained it, put in a new glow plug and it fired up on the first try.

After letting an engine set that long. I would at least remove the back plate and check the rear bearing if you can detect any redish coloring on the crankshaft, bearing or in the case, I would not run it. Then again with the back plate removed and it is nice and shinny
by all means go for it. You can also detect bad bearings by rotating the prop back and forth. if it feels smooth while rotating OK if it feels rough while rotating more than likely you will need to put in a new set of bearings
jerrysu29 Call Sign Wild Man

Try to turn the prop a little. If it's obviously resisting, then the residual fuel has gummed up. Remove the glowplug. Pour a few drops of fuel in. Put a couple into the carb. Give it awhile to soak in. Try the prop again. If it's still gummy, pull the backplate and pour some fuel in. Give it awhile and try the prop again. That usually works for gummed up engines. And as mentioned, with the backplate off you can see what the rear bearing looks like.

I turned the prop and it feels very nice.

I'll likely poor some fuel in before I crank it anyway. How long should I let the fuel soak in there?

Its very unlikely you have any problem! Don,t start making it a problem. I assume its in the airplane all you need to do is drip a little fuel in the glow plug hole and the carb then spin the engine a bit Like Da Rock suggested. As long as it spins free and feels smooth you do not need to remove the engine from the airplane and the back plate just to look. You might ask how do I know what is smooth? Well its a trainer right so we will let it train us. It feels smooth to you after you spun it a bit with some fuel then fine go fly if there are no other problems great you now know what feels smooth when feeling berings in an engine manually.

John