TOFAST4U2C

My Feedback: (2)

I am seeking a very reliable .91 size 2 stroke that can handle a pitts style muffler. I dont know if there is such a thing as I have never ventured past a .60 so far. I want to put it in a VectorFlight Extra 300S. I like the set it and forget it kind of engine as all my OS have been in the past with the basic care have served me well. I know others have had issues but I have been lucky so far. I dont want to chance a OS 91FX as I have heard way to many horror stories on that one. A smooth low to high end transition is important to me as well. Magnum makes a XLS .91A which has some merit. But I havent found a pitts for it yet. Any input from experience would be helpful.
Thanks

Hobbsy

My Feedback: (102)

Try an MVVS .91 with the standard dustbin muffler. Same exact size as the MVVS .61 and smooth as silk running.

majortom-RCU

My Feedback: (40)

I have the Magnum .91 XLS in the VF Extra 66". I believe the exhaust outlet has the same mounting dimensions as the OS. Give BCM a call or e-mail and I'm sure they can fit you. I'm using the Jett Engineering in-cowl muffler, which hangs down lower than the Pitts style, requiring most of bottom of cowl to be cut out. This muffler is a little heavier than the BCM Pitts, but gives a significant power boost. I flew this engine hard all last year, found it to be very reliable. Get it with a couple extra head gaskets and use high nitro, your Magnum will love it.

MVVS .91 also a good choice.

AirGar

My Feedback: (7)

I had a ST 90 w/ a Slimline "Pitts" in the nose of a WM Midget Mustang, That's a nice combo also.

ST's just take a while to break in. Save yourself some headaches, stay away from the OS 91FX!

You may also want to check out the GMS line of motors at Meccoa.com.


Gary

SMALLFLY-

My Feedback: (19)

I have a lightly used magnum 91xls that is very reliable for sale in the marketplace. It was on a ohio yak but I wanted more power.
It has never dead sticked in the 30-40 flights I have on it. The OS 91fx can be reliable you just have to replace the needle valve. I have one of those as well and they turn the same prop at the same rpm. I have used both 10 and 15% nitro in both my 91's and did not see the need for head shims

rc34074

My Feedback: (5)

the st g90 is a great engine- bisson makes a good pitts muffler for it. others have pitts mufflers for it also.

they need break-in as they are ringed engines. 10% fuel, with an idle bar plug.

ed