Engine break-in during colder weather

We had another nice day of good weather here in the heartland today. I thought it would be a good opportunity to take a brand new ABC 2-stroke engine out and run a few tanks of fuel through it. I got the engine started, but I noticed that air bubbles were getting into the fuel system, presumably at the remote needle valve assembly.

I took the time to bypass the remote needle valve assembly and reconnect the needle valve and fuel line directly to the carburetor. By the time I got done, the engine had gotten so cold that it wouldn't turn over anymore.

I could barely hand turn the prop past the point of compression. I tried adding fuel to the carb to loosen the engine, but I couldn't get the thing to spin enough to ignite.

Does anybody have some suggestions for keeping a new engine loose enough to turn freely when it's not 80 degrees outside? I'd really rather not wait until summer to break in this motor.

Reply to
Ed Paasch
Loading thread data ...

Hi Ed, Most likely you will never get an ABC engine to slowly turn through the compression stroke due to the nature of the beast. There will always be a tight spot at the top in cold weather. I once ruined a connecting rod by trying to start an ABC engine with my starter in cold weather. In cold weather, what I do to get them started for breakin is to heat the head with a blow dryer or heat gun. This allows the cylinder to expand and the engine starts fine without the tight spot at the top of the stroke. If you are at the flying field, try warming the engine up with your car exaust.

Good luck Gene

Reply to
Gene

I'm a little bit embarrassed to have to admit my problem turned out to me a dead glow starter. I had charged the glow starter on my power panel, but apparently only enough for a couple of starts. The engine's refusal to turn over was do to fluid lock. At least I'm wiser for the experience.

I took the plane out again today after running some after run oil through the new engine trying to maximize the lubrication. My buddy decided we should try his glow starter and the engine began coughing out all of the crap that had collected in it and we got it running after a couple of minutes.

I got three tanks of fuel through it on the ground, leaning it out then backing off as per instructions. The air bubbles in the fuel line went away with the remote needle valve assembly disconnected, and the engine ran great.

After three tanks on the ground, I turned the motor back to a slightly richer setting and flew it once. No dead stick and it's breaking in nicely. This Magnum 52A XLS two stroke is going to be a monster of a power plant on my Tiger Stick .40.

Reply to
Ed Paasch

PolyTech Forum website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.