I am a returning R/C airplane hobbyist after a 30 year absence. My son gave me a new (old) Tower Hobbies .40 R/C ABC engine but no owners manual. He had it for years but never got going in the hobby. I called Tower Hobbies and they do not have a manual because this engine was discontinued. In days long gone our R/C engines had only one needle valve. This thing has three. One big one and two smaller ones. I want to break the engine in but I'm having trouble getting it to run continuously. Are there any basic setting for these needles like screw in all the way and back off X turns? If somebody has the manual would you please tell me the recommended setting? Also who (manufacturer) made this engine for Tower Hobbies? Maybe I can get the manual from them. Thanks.

Make the big one three turns to start with.

There were two different models of these cars. one had the big needle straight into the carb and the other had the needle at an angle to the rear

The one on top is just a throttle stop screw. Adjust it to where you can just close the throttle all the way

The one opposite the big one goes across a hole on the front of the carb. Make it go half way across the hole in the beginning.

Hi Aug...
Three? Hmmm...there should be a High speed, a Low speed, and the idle r.p.m. adjustment stop screw which is also the carb barrel retaining screw.
The Hi and Low are the only ones you really need to concentrate on, for now...
I would set the high speed at around 3.5 to maybe 4 turns out...

Setting the low speed can be tricky if you don't have a baseline setting. The low speed is the one that's in the center of the carb arm.
While looking down the barrel of the carb, adjust the low speed until the tip of the needle till it's about 1/32" away from the spray bar (or fuel inlet tube ) at Wide Open Throttle (WOT )

Just had a thought...
Tower had engines made by O.S. and I think MDS, so there might be some differences.
The O.S. engines might have an air bleed carb?

Can you post a picture?

The tower 40 has an air bleed type carb. The engine was made b Thunder Tiger and is the same as the old Thunder Tiger GP 40 and is a copy of the OS FP 40

The low speed mixture screw is beside the throttle arm not in the center

The low speed mixture screw is a non event in the beginning. To adjust the low speed mixture it works backwards. Out is lean and in is rich

Ah...O.K. disregard my post then Aug...maybe use it for future reference?

So the old Tower .40 was an FP "clone" made by Thunder Tiger...didn't know that...thought it was a re-badged FP.

Didn't they (Tower ) also have some made by MDS as well at one time or another?

There were no Tower engines made by MDS that I'm aware of. The 40 was made by Thunder Tiger and the others were made by GMS of China.

Horizon had the MDS's from Russia.

Here is a picture of the engine. I'm a little embarrassed to show the mess I made out of the engine compartment. It looks like it's been repaired after a few crashes but I haven't flown it yet. LOL I'll do a better job on my next model.

Thanks for all the great help and information you've already provided.

Your plane looks fine. I'm sure you will enjoy it

THANKS AGAIN. YOU GUYS ARE GREAT! I'LL BE ATTENDING MY FIRST CLUB MEETING NEXT WEEK AND EXPECT TO PICK UP A LOT OF OTHER INFORMATION THERE.

I dug this thread up and it helped get me going. only thing was I couldn't believe how far in I had to screw in the low speed needle. I got that thing screwed about all the way in. It's exactly 1/2 turn from being botomed out.
I flew 2 tanks through it today and no probs , it took me an hour to adsjust needles but seems good now.

10 YEAR OLD gp 40

I have a few of the tower .40's and they are better than the OS FP or magnum GP, they seem to be tighter, more powerful, smooth running low vibes, and have a real ABC sleeve/piston. It's a shame tower discontinued these sweet little engines.

W8YE,
The Tower 40 was not made by Thunder Tigre. It was indeed made in Taiwon but it was made in of all things a sewing machine factory. I do not remember the name of the place but there were a few threads on the origin of the engine. Granted Thunder Tigre is made in Taiwan also and it would be easy to presume that they did indeed do it.
I am convinced that OS had something to do with it's disappearance as it certainly was a better copy then the origional as was the Thunder Tigre
Dennis

I wish the search engine was better and we could ferret out those old posts. The way it is now I cannot get the search engine to stay with Tower 40. Both Google and the RCU ones select both words together and separately even when inside quotes.

Those were the good ole days?? The OS 40FP, Thunder Tiger 40GP, Magnum 40GP, and Tower 40ABC all had parts interchangeability

Hi all...
Found this thread looking for the TH .40 ... which I bought brand new today... lol... the local hobby dude I got it from never even let on that its that old... I thought it was a current model. Am getting my first plane ready hope this thing works fine... I'm using it on an Eagle 2 from Ilsan. Is there anything in specific I should to ensure it doesn't fail on me?

Run some castor oil in your fuel

The Tower 40 was never offered at a dealer discount. Tower branded merchandise is only sold at retail.

The engine was made by Thunder Tiger and is Identical to the old thunder Tiger GP40 which is no longer made

I bought a Tower 40 on sale from tower for $49.95. I have flown it a lot, over about seven years, on a CL stunt airplane. Outboard wing finally folded and I am building another airplane for the engine. I have three or four more I picked up at swap meets, ebay, etc. I think they are really satisfactory engines.

Cool... 7 years... thats a long time wish I can get my trucks to last that long LOL... obviously wont if I keep trying to make them fly...
Here in South Africa mixing your own fuel seems to be a thing only veteran RCers do, but for us simpletons we get a really good local mix called Beetle juice, I got me a 2lt of 10% nitro hopefully this is the right thing for this engine?

The TH 40 does not have ball bearings on the crankshaft.

It has a bushing

It needs extra oil for the bushing

Buy yourself some castor oil at the drug store to add about 30 ml per Lt of fuel