Engine Opinion For 58" Extra 300
 

Hi Everyone, Just looking for an informed opinion on what to power my new VectorFlight Extra 300s 58" plane. The Mfg. recommends a .60-.75 2-stroke or a .70-.90 4-stroke. One of my experienced friends says an OS FS-91SII 4-stroke will be plenty of motor and less problematic than a 2-stroke. From reading these forums, it seems like a lot of people favor a 2-stroke. I have Magic 3-D with an OS .46FX that runs fine. I've never owned a 4-stroke. I would like the plane to have very good vertical. Thanks for the help. Have a great day.

Engine Opinion For 58" Extra 300
 

When I'm eager to get a plane in the air, I choose a two-stroke, because they're easier to set up, get broken in and tuned, and require less maintenance. If I have a few planes already flying and have time available to putz around with a new model, then I like a four-stroke (especially the pumped YS and OS). If you're going to be in this hobby more than ankle deep, you have to acquaint yourself with four-strokes sooner or later. There is a definite learning curve with four-strokes beyond what you know from two-strokes. If you're ready to step up now, go for it. If you just want a plane to fly, a Tower .75 will pull your 58 inches around like gangbusters.

Engine Opinion For 58" Extra 300
 

I have tried a ST75 and an OS91FS and I will say the plane flies good with both engines. The ST can be proped to fly faster. The OS can swing a larger propeller.

Engine Opinion For 58" Extra 300
 

If a OS can swing a larger prop, then it stands to reason that with the proper prop will also fly faster than the ST. OS are very user friendly & hold their value. No question, OS over ST.

Engine Opinion For 58" Extra 300
 

You should not run a 4 stroke as fast as a two stroke of the same size. You can try it but I can run my 2 stroke 12,000rpm. I would not run my 4 stroke that fast!

Engine Opinion For 58" Extra 300
 

A 4-stroker will usually weigh a bit more than a 2-stroke.

That being said, I'd use a 2-stroke.

Your flying an aerobatic plane. Weight is a killer- especially in a smaller plane such as the one your flying.

Heavy aerobatic planes fly like a brick and they land even faster.

Get a hot 2-stroke for your aerobatic plane and leave the 4-stroke for the guys flying Kadet Seniors, where weight is not an issue.

You just can't beat the power/weight ratio of a 2-stroke.

The only 4-stroke I ever saw that had almost the same power as a 2 stroke was the Saito 180. I used to run big ST engines. The ST3000 is a 1.8 engine and it weighed about 4 ounces more than a Saito 1.8 Both engines used a ton of glow fuel, but the ST would swing a bigger prop. Most guys will use an 18-6 or an 18-8 prop on a Saito 180. My ST3000 would swing an 18-10 at more RPM than the Saito with the 18-6. I would sometimes use a 19-8 prop on it. I even used a 20-6 prop on my ST3000 for awhile. That prop was spinning about 7000-7300RPM. You won't find any Saito 180 running a 20-6 prop at those RPMs.

Go with the 2-stroke.

Engine Opinion For 58" Extra 300
 

Hi Guys,
Thanks for the help. I ended up ordering an OS .91FX. I think it should do the trick. Have a great day.

Engine Opinion For 58" Extra 300
 

I will agree that the 2 stroke will be the better of the two.

Engine Opinion For 58" Extra 300
 

That's what I'm putting in my Vector 300 Extra 58"

Tell us how you get on please!

-David C.

Engine Opinion For 58" Extra 300
 

I have a 58" Extra with a ST75 on it.
You will have a LOT of fun with a 91FX!

RE: Engine Opinion For 58" Extra 300
 

I have a Saito FA-80. Do you think the VF Extra 300 58" will be underpowered with this engine?

Kurt

RE: Engine Opinion For 58" Extra 300
 

i have the Great Planes Extra 300, with a 50SX and is VERY well powered. if they want such a big engine on the same size plane, must be heavier, meaning easier tip stalls.

my extra is also 58 inch wing

Scott