stevebss

I bought a tower .61. When I turn it over the engine gets really tight at TDC. So tight it makes rubbing noises and is very difficult to make a full revolution. I have to use a prop on the engine to even make the full revolution. I called Tower and they said it was normal for the engine to be really tight at TDC until it was broke in. As of now, I don't even see myself being able to start the engine. Is this right? The engine is brand new never ran.

XTOL

Yup...its normal. The Tower motors are usually VERY tight.
It can help to warm the motor up a bit with a heat gun
before trying to start it.

But it usually doesnt take too long for them to loosen
up once started. Make sure you give it plenty of break in time.

Mike Hammer

Rcpilot

My Feedback: (78)

STOP turning it over when it's cold. Don't just sit there and flip it over untill it loosens up--you'll ruin it.

Go to the Glow engines forum and do a search on engine break in. There's lots of good info there--but you need to put in the time to read it all if you want to educate yourself.

It is supposed to be tight. That means that you got your moneys worth. It's a good engine.

Go to the glow engines forum and do some reading before you start it. Your engine will last longer and make more power if you do.

50%plane

My Feedback: (5)

You'll LLOOOOOOOVVEE this motor once it has been broken in well.


Woops

kdheath

That's called "pinch" in the business. Some ABC or ABN motors have more pinch than others, but it's normal to have some. The A(luminum) B(rass) C(hrome) engines have an aluminum piston running in a brass sleeve that has been chrome or nickel plated. The sleeve is machined with a slight taper at the top. When the engine starts and warms up, the sleeve expands faster than the piston and yields the correct clearance. Don't turn it over dry and cold. When you do start it, run it in a wet 2-stroke. If you run it too rich and slow, it won't heat up properly and the the p&c can be damaged.

lukeshort

My Tower 61 was also very tight to start with but I have been amazed at its performance. Starts easy, never have had a flame out, and delivers more power than I expected. I have it in a 60 size Super Sportster. One of my buddies bought one to replace a worn out OS 4 stroke. He sent it back to Tower because it was "too tight". They sent him another just like the first. So he turned the piston down on a lathe. Now it has compression similar to the worn out OS. The 61 runs and flys his Sig Kadet Sr. just as good as any 40 size engine would. And he's happy.

autoglide

How many of you are using glow plugs with idle bar in these engines?
Does it really have a smother transittion from idle to full throtle?