Hey guys,
I'm in the process of buying a scale extra or cap, in particular the CM Pro Extra 90, or the Great Planes M.Chapman Cap580 46. I am stuck at the decision between 4-stroke and 2-stroke power so i thought i'd ask for oppinions from you guys that fly them at a very high level. Basically im not after a speed demon, i want it to jsut have heaps of performance and vert ability, but not over powered.

I have two options to take:
If i went the GP Cap 580, would i be wiser to run say an OS FS70 in the GP Cap 580 rather than a .50sx/.61FX 2 stroke? What are the advantages and disadvantages of both engine types?

If i went the Extra 90 which has a recomendation of either 90 2-stroke or between 91-120 4-stroke, would an OS91FX be a better choice than say an OS FS90 surpass, remembering that the 90 size 4 stroke is the lower end of recomendation, will it still perform what i am after?

I would say you would be better off with the cap580 and the OS70, (I would run the YS63 more power and it's only a $30 difference) That setup will perform much better than the extra 90 with the fs90, the 91fx may be ok but I really like the 4 strokes on an aerobatic plane. The cap with that combo should have very good if not unlimited verticle. I can't really comment on the 90 with the 91fx, but I don't think you'd be happy with the 90fs, it's too low on the recommended power and verticle will suffer.

4-stroke definetly

CMPro planes are not light weight planes, they are just average for whatever class they are in, if you want very nice performance for the Extra then go for a 120 4C, the Saito 100 might be ok too. A 108 2C would be great stuff! My Edge 540 (90) flies okay with an ST G90 only and she weighs about 8.5 lbs.

As for the Matt Damon I think if you were to read the thread here you can see what has worked.

kankge extra 300s with a os91fx. great combo; unlimted vertical. you will love it!

Far out... that info is awesome guys!!

As i thought the cap 580 in the other thread has performed awesome with the 70 4-stroke which is what i planned to put in that. Everyone has just said that the larger size plane would be better to fly?

I had decided yesterday that i am going a 4 stroke definately, i want that extra torque, not really after max speed just awesome performance and the 4 stroke can give me that. I will probably look at getting a Magnum i think, i would love and OS or Saito but they are too exspensive in Aus, lookin at around $550+ for a 70 saito, and about $450-500 for the OS 70/$550-600 for the ultimate 70.

Do the magnums perform well? From most reports on here they seem to be very good value for money.

The Magnums are are a good 4 stroke engine, and are very dependable. They are a little underpowered compared to the likes of Saito or YS, but are almost identicle to O.S in most aspects. I have Magnums, and Saitos, and have no complaints with either. The Matt Cap 580 with a Magnum 70 4 stroke would be a pretty nice combination in my opinion. I have a 72 Saito on my GP Cap 232 of almost the same size as the 580, and I would have no complaints using a Magnum 70 in its place. I would lose just a touch of power, but it would still perform very well.