My Super Skybolt are going to arrive to me in the end of this week, and I’m going to use a Magnum 1.20 four stroke.
It has been a lot of questions about engine sizes and it is a lot of good comments about that in the forum.

Now to my question: What servo size should I use?
I have read the review in Model Airplane news and the servos used in that article was Futaba 3305 and I have also
read RCU rewiev and there is Futaba S9001 used, and that is a lot weaker servo!
It seems to be a lot of experience of this model in the forum, and I hope someone could help me to sort my question out.

I am using JR DS821's all around. They are rated at 72 oz/in and are working great. At $29.99 each, they are also affordable.

The 9001 servo is an excellent servo. I have a pair on the elev. of a 14 lb. gasser. 150 flight no problems. Those should be good for ail. & elev. I would however go with something a bit stronger on the rudder.

As a point of interest I had a Goldberg Ultimate with 2 - S148 standard servos on the ail. After 10 years and 1100 flights they were still in there working fine.

Ok I use the 9001servos to elev. & ail. But should I use
the stronger S3305 to the rudder then?

If there are 2 servos for the elev. the 9001 are fine if there is only one servo I would consider a S3305 for the elev. also. Better to ere on the side of caution.

There is one servo to the elev. So I’m going to follow
your advice to use the stronger S3305 servo,

Thanks for your advice Don!

I wrote the review for RCU Magazine and used S9001's all around (Except for an S3004 on throttle) and it was plenty of servo for this plane. I have switched from an OS 91 to a YS 91AC and I plan to stay with the S9001s

Thanks Mike!
I have not order any servos yet, and it seems to work out well with the S9001 servos
And they are not that expensive as the S3305 so it saves me some bucks too
I’m really appreciating the advice you give me, thanks a lot!

Best regards.

That's what I'm planning to go with, too. I'll stick something else on the throttle, but those DS821s just seem to have the sweet spot at the moment. What with so many Spektrum DX7s being sold, there are lots and lots of new DS821s on the market, too. I saw 4 NIB go for $40 the other day--how can a guy beat that?!

Tower Pro 5010's Hi Torque servos in mine @ 9.00/ea do just fine and have held up very well for me on various planes.