[Flyinbullmax]

Hi, I have a Os .46 Fx that I just got from a friend. It looks fairly new, I cleaned it in my crockpot overnight with antifreeze to clean it. Before cleaning it was hard to turn, I thought it was because of old oil and fuel but no, bearings are in a very good shape but the piston jams in the upper part of the sleeve(TDC). So much that it stops the engine. The engine wants to run but piston is too tight in the sleeve. Anyone had a similar problem or what is hapening to it?

JP

[rambler53]

Pull the liner out and inspect it for nickel liner failure, like this one that peeled years back on a VF 61 ABC engine.

[Flyinbullmax]

Nothing apparently wrong. Exept that the piston starts to jam at 1/4 inch from top of sleeve.

[rambler53]

Did you inspect the liner? Removing the head is easy. The only "jam" I ever encountered is with a new ABC engine that hasn't been run yet, it's a natural pinch at TDC. You've tried to run this one?

[Cougar429]

Look in the exhaust port. Does this motor have a ring? If so, it sounds like it's stuck.

If not, pull the head and check for the liner peeling, as mentioned before. If it looks OK, check there is not a layer of glaze near the top of the cylinder. You may have to bake it with the head removed and piston full down to completely clean it out.

p.s. Don't forget to oil the bearings before doing any spinning of the crank after this process.

[leopard1]

Put it back in the crockpot for about 48hrs. I found overnight was too little time. I usually just put a motor in for 48hrs on low. After 48hrs, I pull it out, let it cool a little and as Cougar mentioned, oil her up. Cleans mufflers up like new as well!!

[Youngguy]

Some of the FXs were very tight on the top end because of the technology used to seal the piston and liner. Make sure the engine is lubricated and heat the top of the engine with a hair dyer and check if the engine will turn over. It still be tight but if it does, do the same thing before starting it. After the first run it will turn over easier and you will have a very sweet running engine.

[AJCoholic]

What he said...

I have had several brands of abc type engines that were so tight, they couldn't be idled before an hour of run time or more was done. But after that they were and still are some of the best engines I have ever run.

Ajc

[E Smith]

If this is a tapered sleeve engine you have a good one. Put the engine on a test stand. Mount a prop that is about one inch smaller in diameter than is recommended for general use. Get it ready to run. With a blow torch gently warm the top of the head until the engine turns over by hand. immediately start the engine. Bring the rpm up to the recommended amount, setting there should be smoke and some oil cming pout of the exhaust. The smaller prop allows this to happen at a richer setting. Do not run it slobbering rich. Two or three tankfulls and it is ready to go.

All of the above, only if it is a tapered sleeve engine.

I "first run" all of my racing engines in this manner.

Ed s