Buliding a 60 size ultra stick and have yet to choose an engine. Narrowed down to several choices, Tower .75, Magnum .91xls, OS .61fx. what are you guys running? Leaning toward OS .61, does it have enough power to hover this plane? Or should I just go to the .91?
Thanks.

I am using a OS 91 surpass and I like the power of four strokes. I don't like tower engines and will never try another. I have a Magnum XL108A on an Extra 300 and it runs great 9500 rpm on a 15X6 with 15 % fuel. A magnum 61 would be worth a try.

A 60 sized plane with a 60 sized engine? The Tower-75 has much more power than the 61FX and mine runs perfectly.... Not a dead-stick yet!

I would say:
Tower-75
Magnum-91
Then 61FX

I tried a YS .91FZ on mine, too heavy, put my Saito 100 on it for a wjile then needed the 100 on a Kellett AutoGyro so it now has n MDS .68 on it. the balance is perfect with the Saito 100 and the MDS .68. I couldn't put the battery back far enough to balance the YS which weighs 7 OZ more than the Saito 100.

The Saito FA-100 4-stroke is the ideal mate for this plane. It will give it all the power you want and then some and is a very reliable powerplant. If I was to go with a 2-stroke then I would be looking for a high-end 60 or 90. Anything larger than the 2-stroke 91 is very much overkill for this plane.

I have the ultra stik with the magnum 91. It has all the power you could want. Unlimited vertical, very fast and will pull out of a hover without a single problem. Just make sure you put the servos in the tail and you will have no balance problems. Also, put the battery in the back of the radio compartment. That should get you at manufacturer suggested CG to start. Then as you fly it more, you can make an hatch and put the battery in the tail.

Also, get a larger tank for that motor. I suggest a 16 oz.

I second Razor's position on your choices....however, I would probably
go with a Magnum .91 four stroke....that would be sweet.

....the Magnum .91XLS is overkill.....
....the OS just doesn't produce the power to justify the cost....

Dave.

I don't think you'll hover with a .61. I would go for a .91. I have the Mag .91XLS, OS .91FX and Mag .91 4-stroke. Any of those would do. With the OS, you'll need to fix the needle valve. The Mag .91 4-stroke would be a good combo. If you get it, it's a ringed engine so break it in slobbering rich and add some extra castor to your fuel for the first 3 tanks or so. I kept mine to 4000 rpm or so for the first 2 tanks, then slowly increased and leaned out. The ring seated and the compression came up great.

With the XLS or OS, you can get the Ultra Thrust muffler for 800-900 more rpm.

Okay, So I decided to go with the Magnum 91XLS. For $129 you can't go wrong there. Everything is mounted and ready to go, 2 servos in the tail just forward of the vertical stab, pull/ pull on the rudder. This shoud be sweet. I do have a bit of a balance problem though. Manual states 4 and 1/8, mine needs to have the battery (standard 4.8v) all the way in the tail near the servo's and some extra lead (3 ounces) to get that balance point. Anyone else had this problem with a ultrastik and 91 XLS? From what I've read here and elsewhere this engine isn't that heavy to cause this situation. Am I missing something? Or do I just add the weight. I was thinking of going with a 6 volt battery with 1000 mah to handle all those servos, I presume that would cut down some of the lead I need to add. Any suggestions?
Thanks,
Todd

I'd go with a 1300 ma battery, 4.8 volts....with the 22mm fat batteries.
That will add about two ozs.... with 7 servos, you need all the battery.
Cermark sells them for $13.00....can't beat 'em.

Dave.

By replacing the stock muffler with the large volume pits muffler you remove almost 3 ounces from the engine to help balance it. It helped on my stick.

Definatly the .91. I started out with a Saito .91 on mine and it performed great. The Saito went bad and I put my old Magnum .91 on and it is still performing great. Use throttle management and it will be fine.

I am flying a stick with a Thunder Tiger Pro 61 on it. It flies well but I did have the weight problem as well. I replaced the Stock muffler (6oz) with th MACS tuned pipe(3oz) to take care of most of my problems.