Hi. I'm fairly new to planes and have a Goldberg Eagle 2 and a few questions. My dad built this plane a good seven years ago and the job of getting it flying is mine. We've bought the electronics for it, so we're good as far as servos and what not. However, here is my question. The engine is an old OS 4 stroke .65 that has been sitting for YEARS. The old beast still turns and has compression so I'm pretty sure it will fire. But facing from the frong of it (propeller nose toward you) the front right mount is broken. The engine is mounted in the plane and for that broken mount, we shimmed it off with a bunch of washers to get it to sit right and tight. My dad things it will be fine to run it as is but I disagree. What do you think? Is the engine going to break off in a spiral of death or will it work? And another one of my worries is that the engine is to big for the airframe. The plane is only rated up to a .50 in 4 stroke. (.29-.45 2 strokes, .46-.50 4 strokes)

If we should get another engine, what do you think we should go with? Reliablity, longevity, and a decent amount of power. Any advice?

My first airplane was (and still is) an Eagle 2 ARF with an OS 46LA on it. I'm thinking that the 65 4 stroke is a little much. Even if you keep it throttled back to control airspeed, you may have so much thrust even at idle that the airplane will never want to land. You may also find you'll need a larger diameter prop to "absorb" the thrust from the engine. Too big a prop will cause a problem trying to taxi/land. You won't have much c;earance between the prop tip and the ground. You may end up breaking a lot of props.

When you say the mount is broken, are you talking about the mounting lugs on the motor or the wooden plate the engine bolts onto and which is glued to the wooden beams on either side of the nose?

The mount on the engine is broken. So the actual metal plate that the bolts run through into the wooden mounts. My prop is pretty large already do I don't think that would be a problem. But landing is an issue like you said. I didn't even think about that!

That's an awfully big engine for that plane, especially in a trainer mode. However, you can take satisfaction in the fact that you can fly all day at half-throttle.

Fixing the broken mount is easy. Clean the area thoroughly with a degreaser. Use JBWeld to rebuild the mount area. When it's dry, redrill the bolt hole.

The Eagle 2 is a FINE trainer and will serve you well.

Dr.1

JBweld huh? Is going to really be strong enough? I've had a few bad expirences with lol. I've heard good things about the Eagle 2 so thats a bonus. So its ok to run it with that engine? That should save a good $70 or so

My first trainer was the Eagle 63- the predecessor to the Eagle 2. Much later I built an Eagle 2 for a knock-around plane and to give visitors a trial flight. IMHO a .65 4-stroke would be way too much for it, plus four-strokes are more complicated to work with, and the broken mount is a bad thing too.

If I were you, I would buy an OS .40 (maybe .46) LA engine from Tower Hobbies. Easy, simple, reliable engines. Spend less time dinking with an engine and more time flying.[8D]

We fly the Kid's Eag;e II with an OS FS 40. It's not a power house but it's a nice flyer..
How's the balance? Mine came out dead on eith the FS40 on the nose.

I flew my 40 Telemaster with a OS .61 FS.. It was a bit of a pain to land.. It wanted to float forever.

I think we'd have to see pics of the damaged lug to pass judgement on it's safety.

I'll see what I can do as far as pics. We haven't really balanced it yet. The electronics aren't in it yet but hopefully either this or next weekend. Also need some fuel. But as is, the balance is pretty heavy to the front. By no means is that engine small...

That 65 size engine is too big for you Eagle 2, all that plane needs is a good .40 and that will be more than enough engine. With the .65 the propeller won't have enough ground clearance, even with my 40, the propeller has grass stains on it! Eagles are great trainers, the fly really well!! You'll love it!!

I will have to agree with most people here, the 65 is way too much. I had a eagle 2 that I bought from a guy who built it, installed everything and never flew it. It sat around his house for 6 years. I got plane, engine and radio equipment for $150. Seemed like a great deal to my wife at the time when she bought it for me for Christmas 3 years ago. She didn't foresee the addiction that soon started. Anyway with that 65 the eagle will not want to come down. I had a OS 40 FP (predecessor to the la) and the plane flew around fine but still wanted to float all day on landings. I got to the point where I could put it one click above idle and run the wheels of the plane along the tips of the grass on the run way.

I learned to fly on an eagle 2 as well with an o.s. fp 40. I would say that engine is a little weak for flying off of a grass field. A little bigger engine would be better for that.

I have not run any 4 stroke engines, but I wouldnt be afraid to try the .65 4 stroke in an eagle2. However, as others have mentioned, prop to ground clearance could be an issue. Also, as was mentioned, the eagle2 is a floater, so you need to get down to a very slow idle to land. Try a prop with a lower pitch to keep the speed down. Say a 4 or 5 inch pitch would probably work well. However, going down to a lower pitch usually means increasing the prop length, causing more clearance issues.

A good engine for this plane would probably be a .46 la. I used a 46 fx on mine for a while, and it had plenty of power then. Grass take offs were no problem then.

Well, I'm going to go against the grain here and say that if that's an old OS 4-stroke, it is NOT too big for that plane. In fact it should work very nicely.

I also wouldn't worry too much about the broken mount. You're not going to stress that engine nearly enough to worry about it.

Slap it in and have a ball!

--- and that's the right answer (again) -- he's good

Hmm... Crossed between going with the majority or the two guys that have a combined posting number of higher then everyone else that has posted combined lol. Hmm... Think I'll wait for more info and opionions but I'm leaning toward it being ok

I'll pipe up and agree with Minn..I also wouldnt bother trying JB weld or any other repair (did you know if you actually weld around JB weld it explodes?) to the engine 3 lugs are enough to hold the engine to wood...grass fields hah with the .65 on it you could probably take off from a picnic table (wouldnt recommend it ),,take the time to make sure its balanced....Rog

Anyone else have an opinion?

Go ahead and try it. If you don't like how it flys with the 4-stroke you can always change.

I have a measly OS 40LA in my Eagle II. It balances perfectly without having to add any weight and has plenty of power, even at my club's bumpy grass field on a hot August afternoon. The Eagle II is a light airframe. Mine is a bit of a kite... wants to float on landings and doesn't handle wind very well. It actually might be better with a heavier engine and some weight in the tail.

If you decide you don't like the 4-stroke you can buy yourself a bushed Thunder Tiger 40 size engine for $50 and save the 4-stroke for your next plane. By the way, you may be able to buy a used case on eBay for the 4-stroke. It's usually something else that goes bad on an engine, so you should be able to find good cases around.

Damien - Go ahead with the 65 - you'll have a ball.
I have an eagle 2, for many years, that I use as my workhorse/testbed. It drops bombs,parachutes, piggybacks gliders, takes photos and also goes on floats. I use it also to run in any new engine, so it's had a variety engine sizes installed, from 40 2 str to 80 4str. This last season I have been flying it regularly with an OS 61 2 str.
This is a great plane and with the big fourstroke you will have an great setup.

Well, I think we'll take the risk. We'll put in the order for for an almost ready to fly Eagle two, mount the .65 and have a go. Hopefully it won't be disasterous but I don't think keeping it in the air with that engine will be to much of a problem. Thanks everyone!

the .65 is entirely too, too much engine for the Eagle II even a good .45 /46 schnurle is plenty& many were/are flown on the FP / or LA engines.vibration is going to be a problem not to mention balance.the .65 flies the larger CG Cub with ease . with the larger motor even as 4 stroke fuel capacity will not be enough for longer flights. the FP /LA motors can be bought all day long for around $ 45 used. your problem will not be keeping it up-- it will be landing under power.

I think its too much engine. There have been lots of those planes at our field and the plane can be quite fast with a 46 in it. BIgger than that and you will be fighting the engine trying to get the plane to slow down to land. The bigger prop will want to just keep pulling the plane along even at idle. I had a plane with too much engine on it and I had to cut the engine to get it to land, (unless it was really windy). [8D]

Uh --- guys, it's an old .65 4-stroke. It doesn't make the same power as a modern 65 4-stroke & it certainly won't make as much power as a modern 40 or 46 BB 2 stroke. It will definately not overpower the plane. It will idle slowly & turn a nice big prop -- pretty much perfect for the job. ---and then there's that throttle thingy as well.

The engine is fine and plus when it's a 4 stroke it normally means its about .10-.15 lower in 2 stroke terms. As in a .65 4-stroke is comparable to a .40-45 2-stroke. Plus it's older, not to mean anythings wrong with it it just might not have the same compression as it used to. Only problem with it is, is that it will be heavier, so make sure to balance it well.

The Eagle-2 is a great plane too. Every club trainer at our field trains with them and the only thing to modify when you buy the ARF or any ARF is that ARF are put together with hot glue and so you will want to order triangle balsa and glue it to the bottom inside of the fuse to reinforce the seams. Also glue triangle balsa to the base of the vertical stab for reinforcement of it breaking off in a bad landing or hangar rash cause no one likes hangar rash!

One thing it will probably help the balance. Most planes usually require nose weight to balance but the heavier engine should off set that. [8D]

The CG Eagle 2 is still one of the best trainers out there....period. After 35+ years of flying RC planes, I still keep an Eagle 2 ARF around simply because it's a joy to fly. Plus an Eagle 2 is capable of performing some fairly advanced aerobatics simply by adjusting the balance point and the control surface throws.


Are you sure it's an OS .65 4-stroke? I've been flying RC planes since 1969 and don't remember OS ever making a .65 four stroke. The only OS four stroke sizes I can remember are the .20, .26, .30, .40, .48, .52, .60, .61, .70, .75, .80, .90, .91, 1.20, 1.60, 2.40, and 3.00. Could it be one of these instead? Or maybe a different brand? (For example, Saito makes a .65 four stroke.)


I agree with your Dad. Just make sure to keep an eye on the right rear mounting bolt to make sure it always stays tight.


An old .65 four stroke will definitely be at the upper engine weight limit for an Eagle 2 to fly well. But an old .65 four stroke definitely won't be too much power for an Eagle 2. A modern .52 four stroke will probably have equal power, and a modern .46 two stroke will be more powerful. (My Eagle 2 ARF currently has an OS .46 FX.) Besides, that old four stroke has a throttle to control the amount of power.

HOWEVER.....if this is your very first attempt at flying an RC plane, I'd highly recommend putting that old four stroke back in storage and getting a different engine for your Eagle 2. There's no sense in risking damaging that old four stroke during the training process.


Around here the most popular engines for training with an Eagle 2 are the Thunder Tiger Pro .46, the OS .46LA, the Thunder Tiger .42GP, and the OS .46 FX(AX). All of these engines run extremely well, have excellent throttling characteristics, will idle reliably at very low RPMs, and will instantly accelerate back to full power without hesitation. Any engine with those four qualities will make the training process much more enjoyable for both you, and your instructor.