TT .61 engine problems
 

Hi, I have a TT .61 pro engine that's just been taken out of storage for the past couple of years. The engine was stuck, so I boiled it in water to release the moving parts. Upon opening the back of the engine, the bearing was rusted, but I couldn't take out the bearing because the piston sleeve was really stuck to the body. Anyway, I cleaned it out as much as I could, then put the engine on a brand new thunderbolt. The first problem to occur was that it would not hold an idle without the glow plug attached to it, and it would not accelerate cleanly. I took it out of the thunderbolt and put it back into my pattern plane, coupled with a hatori pipe. I had problems with my idle again, so I changed the glow plug again. Now, my main problem is that it will sometimes idle all right without the glow plug attached, and sometimes it won't. If it idles all right, then I have problems with the transition from low to high speed. It accelerates, then just dies on me. I tried leaning out the mixture and richening it, but it really didn't help anything. I tried resetting the low speed needle, but it still doesn't help. This is really driving me up the wall, as this engine has already damaged both planes that it was put into. Fuel is blowing out the carb as well. Another thing I didn't mention was that the low speed needle is countersunk, and about 1/4 of the surrounding sleeve was broken off by an attempt to move the throttle barrel with a vise plier whilst it was stuck. Will this affect the performance of the carburetor? I have never had any problems with this engine. Any dvice or help will be greatly appreciated. Thanks!

RE: TT .61 engine problems
 

You have several problems

Sounds like your fuel is old also?

RE: TT .61 engine problems
 

I just bought the fuel, I'm using cool power 15% nitro, and my other .46 engine runs fine with it.

RE: TT .61 engine problems
 

OK we can rule out the fuel itself being a problem.

There could be air leaks created by the rusty bearing causing the crank to wobble?

Rust particles are most likely going up in the engine and ruining the catalytic action of the glow plug.

RE: TT .61 engine problems
 

Well, I'll try to remove the inner bearing and change it, but could the carburetor also be faulty?

RE: TT .61 engine problems
 

Yes, there could be gunk in it causing your problem?

RE: TT .61 engine problems
 

I cleaned out the carburetor using a syringe and fuel tubing to inject alcohol into the needle. The needle is clean, as there was a steady stream coming out of the needle. Does the cracked sleeve for the lsn also affect performance?

RE: TT .61 engine problems
 

It may. its hard to tell from here. Can you throw any pictures up on the screen for us to look at the damage?

RE: TT .61 engine problems
 

also, the exhaust coming out of the pipe is black in color...

RE: TT .61 engine problems
 

That is not normal but may eventualy clear up if you can get it running right.

Try to collect some of this exhaust residue on a sheet of white paper. Let it drain down the paper to get thin in places. Look at the mess to see what kind of particles are in it. Try to compare it with the rust you saw on the rear bearing?

RE: TT .61 engine problems
 

ok, will do. I'll try to change the bearings first to see if it will help any. I'll post again as soon as I get it done and tried running the engine. Thanks so much!

RE: TT .61 engine problems
 

Cyborg,


Getting the sleeve out to disassemble the engine, should be possible after heating the engine in an oven, for 20 minutes, at about 180 degrees C.

Do it after first removing the head, the back-plate and all loose parts.

When it is hot, turn it so the piston is at BDC, from inside the cylinder, stick a small piece of wood in the exhaust port, turn the engine and the piston will push the sleeve up far enough, so you could pull it out completely.

Mark the back side of the connecting rod and un-hook it from the crank-pin, to remove the piston+rod assembly.

Allow the engine to cool completely and push out the crankshaft; it should come out alone, without the rear bearing.

Heat the crankcase again, so the bearings would drop, or be popped out, by wrapping the rear of the engine on a piece of wood (rear bearing) and the front bearing is pushed out (forward) with a wood dowel.

RE: TT .61 engine problems
 

You can use a zip tie to replace the piece of wood, it will come out without heating the engine at all ... I do it that way very often.

RE: TT .61 engine problems
 

Dar forgot to mention you need to remove the drive washer and split collet before you can slide the shaft out of the case. Also while the engine is apart I would replace both bearings rather than just the inner one.

RE: TT .61 engine problems
 

Paul,


I did not forget this. I believe this engine has a keyed drive washer, which needs no puller to remove. It just slips off.

If I am mistaken, then yes, the drive washer has to be removed (with a puller of some sort, I am sure someone will post a photo...), prior to pushing the crankshaft back, or it would not move a nanometer...

RE: TT .61 engine problems
 

...And Cyborg,

This engine has an ABN piston and sleeve...

Even the makers of 'Cruel Power' don't recommend it for this type of engine; specifying 'Omega' fuel instead.


Using the all synthetic fuels for these engines may keep your plane cleaner, but Omega with Castor oil will be easily wiped off with Windex and a rag, while keeping your engine in better shape, for longer.

RE: TT .61 engine problems
 

Cool Power is used by many people without any problems. Just remember to keep the mixture rich.