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Extra 300S with a .91 4stroke?

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Extra 300S with a .91 4stroke?

Old 04-03-2004, 08:26 PM
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Default Extra 300S with a .91 4stroke?

I bought a Great Planes Extra 300S .60 size

Requires: 2-stroke .61-.91 cu in (10-15 cc) or 4-stroke .91-1.20 cu in (15-20 cc) engine

I am going to buy a O.S. .91 4-stroke I think

My question is, do I need a onboard fuel pump for this .91 4stroke

I know if I was using a 1.2 or higher 4-stroke I would need it.

Also please tell me all or any findings that you have found with is plane and engine combo.

Pros and cons..

Thanks Jeff
Old 04-06-2004, 01:44 AM
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Default RE: Extra 300S with a .91 4stroke?

I wouldn't expect "out-of-sight" performance out of that combo. I have a .91 4-stroke in my .40size GP Extra, and it's decent performance, however, I've seen and had better. The plane is built very decently too(I have to say...I built it..hehe). It does have totally unlimited vertical, but with some of the power-to-weight ratios as high as they are..I've got planes with higher ratios that climb out alot quicker then that one.
The .40size Extra is NOT alot smaller then it's slightly bigger brother the .60size. I've seen the 2 planes side to side..and not a big difference. Matter of fact, the first .60size I saw.. was on another pits table at my flying field..and I had to get the 2 planes(mine and the other) nearly side to side to tell a big diff, and then it wasn't as big as one would think.
Go with a 1.20 at least.. It will handle it well. It's not a 3D ship by any standards, unless extreme measures are taken, so for IMAC style of flying, a 1.20 will pull it through anything gracefully I'm sure. Just as the .91 does for my .40size, which it really does do a nice job for that style of flying.. I just know I would put at least a 1.20 in the .60Extra. Good luck.

PS....I don't think you'll need a fuel pump of any sort. The 4-strokes do have a good draw on the fuel.
Old 04-15-2004, 10:39 PM
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Default RE: Extra 300S with a .91 4stroke?

Hi Wounded, I have the same plane with an OS 91 four stroke with pump. I built it in 2000. It is a great flying airplane and have never had a problem except for a lost muffler once. It is the first plane I use at the beginning of a flying season and any time I am rusty as it is a very forgiving airplane. With the 91 the plane can be slowed to a crawl for real pretty landings. I wouldn't trade mine for anything. (well almost anything). It does pitch a little to the belly in knife edge but that is easily mixed out with your radio.

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