It's been a few years since I've flown. Please keep that in mind as I ask my question. I have a pretty old Piper Cub that I believe to be a Carl Goldberg. It's about a 5 foot wingspan, I suppose, and has been crashed so many times, it's now wood holding glue and box tape together. The guy I bought it from said he built it by shortening the wings 6 inches on either side and put a KB 61 engine on it because he wanted a "hot" plane. And there is no cowling on it, so it's just the flat-fromt firewall with the motor attached. Obviously not all that aerodynamic. BTW, the wings have their customary round ends, not cut off straight. So I suppose he built it leaving 2 or 3 spars out on each side.
Anyway, the KB61 engine is totally shot, and I just want another cheapie of some kind just to get it back in the air. But I don't want another .61. That engine was just too powerful and with those short wings, the plane was a real handful. I don't want all that speed, and my reflexes and nerves used to get frazzled flying that thing. Anybody got any recommendations? And since the plane is so torn up and nothing on it is straight any more, all I want is just some used cheapie motor to get going again. Thank you.

Welcome to the forum. Sounds like a job for any .40 to .46 size engine then. You don't have to go full throttle, you can even adjust things ahead of time to block it out. That would save some $ if you can get the K&B going again. A lower pitch prop will slow it down too. Maybe a bit more oil in the fuel will get the K&B running, or ?

No, that KB is junk. The glo-plug threads are stripped, it has no compression, and has the old-style square carb. Doesn't have enough compression to even draw fuel. Just terrible.

The more I think about it, maybe a 46 would be best. That plane has a big fuselage, short wings, and a flat front. Plus it's twisted out of shape from so many crashes. If I even got it flying with a .40, I'm afraid I wouldn't have enough power to get out of trouble, like wind, or a bad approach. That junky KB 61 made me the king of dead-stick landings. It cut off all the time. I got so tired of fighting it.
But if I did dig up a smaller engine, I haven't a clue as to what propeller I'd need. Certainly don't want a nice valuable engine. Because the next time the plane crashes, I'm liable to walk away. It really is ragged out. That plane has been crashed so bad several times that putting it back together was a prolonged joke.

Pick up an ASP .46 for $74 at hobby king, bolt it on and go fly. It’s cheap, parts are cheap... Put an 11x5 or 12x4 on it. Maybe an 11x6, but that might be too fast? The ASP is an incredible value when you consider it’s true ABC and it’s pretty inexpensive new.

You could install a four stroke glow engine. Anything from 40 to 70 would work fine and sound better than any of the two strokes.

But the engine will cost more and you had mentioned that you wanted to keep costs down.

I have been picking up older Supertigers and OS FSR, LA, FX, AX .46 to .55 motors for $20 lately since they seem to have gone out of fashion lately. I waste a lot of time at swap meets.Nearly every one works well. I would fix your glow plug thread on the K&B, but you likely don't have a lathe. I get pretty good at deadsticks too.

The OP did say they don’t want to sink a ton of money into an engine for this plane. Typically cubs get 4-strokes, but I didn’t suggest that due to the higher cost.

For a beater plane, a beater engine is in order. I personally would go cheap - especially if I have a habit of crashing.

I don't know what "nothing is straight" means, plus the tape holding it together, but it sounds like you have some work to do on the plane first, otherwise just putting a motor on it will be a waste. You might want to strip the covering so you can fix it properly and then use the frame to practice learning to cover.

Also, you need to weigh the plane. If it's heavy it might not be worth fixing.

I haven't flown in a couple of years and my old beater Sig Something' Extra will be what I fly when I get to flying again. It has a .46 engine on it. The plane was crashed either 8 or 9 times when the builder gave it to me. I've crashed it twice and had a midair with another SSE moving fast. It is covered with Econokote, Ultracote, and Monokote. It's an honest flying plane that have never let me down, so I'll bring it back to life. It doesn't matter how they look or how rough life has been for them.

I probably have something I could send you for $25 S&H. email me if you are interested. [email protected]
It would be something in the .60-.75 range. While the .46 would fly your Cub just fine. I feel like you are going to have CG issue with that small engine. A Cub has a really short nose and you will have to add lead to get it right with a .46. IMHO.

David

Some kind .60 4-stroke.

Hard to beat that deal!

RE: K&B .61
Hey Henry, did you ever think YOU were the problem? The square carb is great, easy to tune and smooth transition. If the glow plug threads are stripped, WHO DID THAT? I have been flying with multiple K&B .61 engines for 40 years. Never a dead stick, low idle, great mid-range and top end. It is an extremely reliable running engine. Instead of bad mouthing an engine because of YOUR limitations, maybe just keep your unfounded opinions to yourself! There are many who have flown with K&B engines and are very pleased with their reliability and durability.

What’s with necrobumping these old threads to chew out the OPs who are probably LONG gone?

I had the same thought. If someone is looking for HELP it might be worth the gamble to bump an old thread, but if you are giving ADVICE to a four year old inquiry, chances are the OP isn't still waiting with baited breath for a response. Just saying!

Some of these threads are literally 20 years old with people poking in to add their advice. It’s a little bit odd that it’s been happening so much lately...

Yep, must be a conspiracy
Like one of those gang- attacks, coordinated in back channel PMs and e-mailings by a vindictive hate
monger

A bit hard on the OP anyhow. I didn't see his comments as K&B bashing. Just saying his particular stray mongrel sample had been a bit more than clapped out.

Otherwise, regardless the age, good to have on topic info under one post. Works fine for most RC engines.