Hi I just bought the GP Ultimate Bipe 40 kit ! and planed on useing a Magnum 61 4 stroke. but a friend told me i wont like the power of the 61 for that plane ! he said its too small and i should use the 61 on the Piper Cub kit I have !! i have a magnum 52 4 stroke i bought for the cub . Its the Sig 71 wing Piper Cub J3 kit calling for engines between .19-.35 size.
is there anyone out there that can tell me if im all wet with my selections here ? or if they have had experiances with these engines and the same setups .
I welcome any and all input ! these are my first 4 strokes and i hope i like then !

Ron:

To start with, the Magnum 61 should be plenty for the biplane, and the 52 4C should make the Cub fly nicely.

Tell them all to go jump.

Bill.

Either one of those engines will fly the ultimate. The magnum will be great. I have one of these and I fly it with an OS 46 FX and it has plenty of power to do everything but hover. It would probably hover but I am not a skilled enough flyer to try it. My bipe will do everything that I am capable of with the 46 on it so the 4 stroke should be fine.

Rick

Rick:

I said the use I did because I think the 4c will make the Cub more pleasant, and the 2 stroke sound wont detract from the biplane.

Bill.

this is making me feel better ! I was starting to feel I wasted my money for these engines ! even thow I got a super deal on them.. thanks for your input and i hope that anyone reading this thread and can add thier $.02 worth will do so !
Thumbs up to RCU

A friend of mine has an ultimate 40 also. He use to have a .46 thunder pro and upgraded it to a .91 Magnum 4 strk. here are some pictures of us breaking in the engine.

I am using an OS 70 FourStroke engine
on my GP Ultimate...
Excellent flyer with engine, almost unlimited
verticals and still is a good floater relatively
to a bipe!
I love flying this plane, have casted a fiberglass
cowl as well as wheel pants.!
Have changed to two seperate servos (in the wings)
for the ailerons and fibergalssed the fire wall
as well as the adjacent fuselage walls.
Have placed the battery in the middle of the fuselage
and am just on the recommended CG....
Regards
Hisham.

I have two Magnum 61 four strokes and both run strong. If you need a little more power after its broke in try some 20% nitro (Cool Power Pro Pattern or equal) what a difference! I know Magnum call's for 15% max with caster, but I've been using the 20-20 for two years with no problem. The Magnum should be fine in your Ultimate.

Hisham,
What kind of luck have you had flying with wheel pants at your flying field. Are flying off of grass or dirt, etc. or are you flying off of a paved surface?

Thanks

From a paved runway...
Tried to attach a pix. but with no luck today!
Cheers
H

pix!

What about a K&B .65 Sportster on an Ultimate? Prop suggestions..

please don't broke in engines on the ground, where they can suck up dirt or sand in the carb, use a table or a cardboard, or something.

Hey cruisemissle:

How did the GP ULTIMATE 40 fly with the magnum 91 4 stroke?
My Dad is building me one this winter and I have an OS91FSII looking for a home.
Since I don't think I can squeeze the pitss muffler and a 61fx under the hood I really am interested in how the 91 4 stroke worked out.

Thanks
Eric

Tommy, that motor would yank that plane around real well. I love 65 Sportsters. The only concern I would have is ground clearance. You can really swing some serious lumber with a Sportster. I had a 14-6 on mine in a Bingo. Had clearance problems. Flew fantastic though. I would say prop it to around 9200 rpm max and have at it.

Mark Shuman

You can fit the .61FX fine. You have to cut a hole in the cowl for the Cyclinder head, but you will with the 4-stroke too. I have a .61FX in my Ultimate and enjoy unlimited vertical. It's great.

Here's my Ultimate. As you can see I have very little imagination when it comes to covering schemes[&o][&o][&o]

Powered by an OS 46FX which hauls it round OK. Had one before with a Saito 65 which also flew OK until I had a deadstick in a very bad position.

Terry

What about a Rossi 40 with pipe for this plane?? I have one lying around and just waiting to get airborne again
I havent started building, and as this is my first kit i need all the tips i can get


Frode
Norway

I am in the covering stage of my Ultimate now. I am going to use a Saito 72 in it. There were lots of posts that recommended that combination a few months ago. I have been working on this project for quite a while due to illness, etc. so I am anxious to get it finished and in the air.

Good luck with whatever engine you choose.