I'm building a 4*60 and curious as to what four stroke engine sizes are used. I've got a Magnum 70 and a thunder tiger 90. My instructor recomended the 70, saying the 90 is to much engine. Any comments??

Don

If you are going 4stroke, I would choose the 90, the 70 is more of a 40-46 size plane motor. Just my personal opinion, but I would not put the 70 on it, I have a Sig SE which is a 40 size plane with an OS 70 4stroke on it and its great, but I dont think I could put it on a 60 size plane and be happy at all.

That was my thoughts also, just wanted to make sure I wasn't out in left field with them.

I've got the 70 on a Ruperts Dad now, and the designer called for a 52-54 four stroke on it. It's hot, but it flys well. I first put a Magnum 52 four stroke on it and I needed 7 1/2 oz of nose weight to balance out, so I figured 7 1/2 oz of more motor made more since than 7 1/2 oz of lead. It just a bit to much for me right now, so I'm going to try the finish up the 4* in the next few days.

Don

i have a 4 stoke 90 in mine and its a great fit and flie nice with a 90,you wont like a 70 trust me on that

I absolutely agree with theo. I too have a 4*60 with a OS 91 FS, and it flys just fine. The 70 would be a real disapointment in a plane like this. Have fun with it, you will really be happy with this plane!
[8D]
D

Depends on how you want to fly it. I have a Saito .72 in mine, and I love how it flies. Now, if I were to buy an engine just for this plane, then I might go with a .90 4-stroke, but as it was I had the Saito on hand. I was pleasantly surprised. It obviously does not have unlimited vertical, but it pulls up nicely from level flight, and does all the aerobatics I want from it. It is in no way a disappointment with that engine.
-Ron

I agree with the others. I have an OS .91FS on mine and it flies great. Another guy at our field use to fly one with an OS 70 that flew the plane, but was not enough power for anything but basic loop/roll. Go with the .90.

Have Saito FA-91S engines on all three of my Four Star 60s, the latest of which is in the member gallery (2 pics). There is a little stick on the right of most transmitters that controls the throttle. When you get used to it, a .90-.91 4-stroke is great, some even prefer the 1.00 Saito, a good .60 2-stroke is fine or a .75 ST engine.

Better a bit overpowered than a bit underpowered..

I have a 91 4-banger in mine, and love it. I've also had a [finneky] 90 2 stroke on a pervious one. Good too!

Just remember bigger wheels to give you more prop clearance

Looks as if the 90-91 four stroke wins hands down.

Dr_wogz mentioned props, what props are you swinging on the 90's?

Don

I've had 2, one with an OS .91FX and the other with a Magnum .91XLS, both with Ultra Thrust tuned mufflers. Nice power, great vertical. You need to go with the .91 4-stroke. I also have the Mag .70 FS and it's good on a .46 sized plane. The 4*60 is too large unless you want to putz around.

The gear on all the 4*s is crap. I moved mine the the wing, wide spread. It gave excellent tracking, hands off, on take off.

Go with the 90 four stroke,I have a ST 75 in mine and it's great,you will not be a happy camper with anything less. Infact im going to build a second one with a saito 1.00 in it.
As far as the landing gear goes,yes its a little weak but i haven't had any problems with it.
and dont worry about prop clearance you got plenty