Which 91 2 stroke engine Should I get that is sub $150 ? There seems to be several candidates Magnum XLS , TS , OS, ST and Irvine. I wish TT Pro would make one ! Engine needed for a 66 inch Vectorflight Edge 540 . Tks

Personally I'm partial to OS. But I don't think you'll be doing that plane justice with a 2C...I would go 4C without a doubt.

There's been mixed results with the OS .91. As a result, I'd go with either the Irvine or Supertiger.

I think people had better look closer at the Irvine line. I couldn't find an Irvine .90/.91 at the Sig website or the Just Engines one. Those are the two biggest Irvine dealers I know of.

P.S. the reason I went looking is that I'm also in the market for a .90 2-cycle.

The main ones I'be turned up are O.S., Supertiger, MVVS, and Magnum. Seems like a hole in the marketplace to me. I would love to have found that Enya or Webra made 90 2-cycle engines. I'm a little skittish about MVVS having zero experience with them and no friends that do either.

Wiz

Mike,
Webra use to make a Speed 91 two stroke that was a real stump puller. Every now and then I'll see one NIB here or on ebay. Pete

Thanks Rocketman.

From what I know of that old Webra .91 it had a funny carb design that wasn't always easy to deal with. A new one with a TN carb would be high on my list.

Wiz

Actually, Webra has replaced that .91 with a new compact light weight one on which they recommend a 14x10. Webra has recently been lowering their rpm ratings and increasing prop pitch recommendations. They are really stump pullers now. Call Paul at Paul's model supply to find out more. I just ran my older converted Webra .91 today, it turned a 14x11 Graupner at 7,550 on Davis Diesel fuel.

I don't know how to get ahold of this Paul fella. The Webra website lists a new 90 size heli motor here. http://www.adis.at/webra/neu2002/neu2002_e.html

It dosen't look adaptable to airplane use to me.

Wiz

Another interesting .90 size engine out there is the Magnum .91XLS. I generally, don't think of MAgnum as a quality engine, but you see an awful lot of people here on RCU that seem to like them. At it's Hobby People price of $149.99 it's cheap enough to have a look......Hummmm I may just do that.

Wiz

Here is any interesting G-90 review: http://www.supertigre.com/engines/supg0235-man.html

I got one based on that review. (In leiu of an OS after reading plenty of grumbling here.)

MVVS make one as well.

hobbsy,
The Horizon Hobby site only lists the .91 heli. Please share info on where to get an aero version. Thanks, Pete

Asp 91 generation 3 s. It is small, light and makes heeps of power. Just Engines has them for about $115 right now.

Curt

I own both a MVVS 77 and a 91. Haven't used the 91 yet, but it is an ounce lighter than the 77 and has a Prettner style carb. It is a work of art. The 77 will spin a Zinger 14x6 10,500 rpms. Using the mini pipe and 5% fuel. Easily hovers my 7 1/2 pound plane at about 50% throttle opening with unlimited vertical. The 91 has been upgraded with a bigger prop shaft, it no longer uses a replaceable stud. It is supposed to turn a 15x 7 prop at the same rpm as the 77 with the same set up. Really looking forward to getting the 91 in the air.

Mike, if you click on "news in English" at the Webra site you can see the Aero .91
"www.paulsmodelsupply.com" or 1-701-237-5814
http://www.webra-austria.at/fra_mot.htm

Flying_Frog, I do have a OS 91 4C with pump but I thought a 2C would give more vertical .

My first vote would be the ASP .91 new gen (O.S. Copy)$115 above . Then the Super Tiger G90 --Just based on price. I would pick the S.T. first if price was no issue.

I had an ASP 91 in my VF Extra. Could never get it to run right. Seemed like it had an old 2 barrel Rochester carb on it that would hang up on high idle all the time. Deadstickes whenever it felt like it too. I was bummed because I was trying to prove a point to th "OS or nothing" members at my club field. Just because I'd look silly if I went out and replaced the ASP with an OS, I hunted around for options. The MVVS struck my fancy, but it wasn't available in Canada. When I called MVVS in Europe, it turned out they were looking for a Canadian importer/distrubutor. To make a long stiory short, now I don't have an MVVS 91, I haev a big box of them!

The MVVS .91 is designed to be a torque monster, reccomeded props run right up to 15x10. My ASP struggled to spin a 14x6 at 10K. The MVVS should easily pull a 15x8 at 10K static according to the factory. The snow has been flying here so I haven't flown my Extra with the new engine, but the build quality is much better than the ASP. I would say they are nicer that even the OS. The MVVS .91 is not ringed. Bisson Custom Mufflers stocks Pitts mufflers for them.

If you are not in a rush to get your plane in the air, I will be posting results if we get a day or two of warmer weather here.

get the g90 and a bisson pitts muffler. it takes breakin as its a ringed engine. mine all run great. they're my standard engine in my warbirds. they do need plenty of cooling air, and they need to run abit rich. use an idle bar plug. 10% fuel. it'll run til you are bored flying the plane .

good luck

ed

The new generation ASP 91 in the small case is a work of art. The carb is as good a quality as the Os in my opinion. If you have not seen, held or tore down one of these motors you cannot compare them to past models AT ALL!!!
I have a marine version and will tell you the port matching with the case is the best I have seen yet. The carb works like a dream. Mine is on a marine pipe and it will turn some rpms now. Best deal you can find. Look on Just Engines site and read the test replys on the engine.

Regards Curt

Does the ST G 90 exhibit the same mid range carb problems like the G2300 esp when using a Pitts style muffler? Tks

If you have to go with a 2 Stroke, I'd say the best 91 for the Edge is the MVVS .91. Several reasons:

1) It's made for torque, not high rpm, so it will comfortably swing 15x6 w/o transition problem or overheating.
2) It comes with a Pitts style muffler, which you will need for the Edge cowl.
3) It is lighter than others.

mine tend to be slightly rich in midrange when i first start them but after few strafing runs (say a couple minutes in the air) the engine comes up to temperature and they are fine. this is affected at the low end of midrange somewhat by the idle setting.

on the other hand i don't fly extended periods at half throttle because i like full speed in my warbirds. i would expect that it would not be too hard to set the carb for whatever speed you would tend to fly. the biggest thing is to get the engine broken in before you try to set the carb too closely, as with this engine the idle settles down after they are broken in for an hour or two. until then you need to set the idle up some to keep them running.

good luck

ed

The midrange of a SuperTigre is easily tuned by rotating the spray bar.

I once had a G3250 that couldn't be tuned for proper midrange..... even by the people at Perry. They offered to set it up in return for borrowing the engine to develope a Perry carb for it. The message that came back is that there was some sort of timming problem and it couldn't be tuned for anything other than wide open or idle.

This info is actually second hand as that is what I was told by Mike Hurley....he gave the engine to me and I couldn't make it work in the midrange....even with glow plug heat. Then I gave it to another fella and he gave it to someone who gave it away to sombody who was happy with running it at full throttle....or so I was told.

I also had a ST G51 that ran well once I found the right plug and filed off the burr on the glow plug seat.....and sealed the muffler with permatex and put a peice of fuel tubing on the needle valve.

I also had a G61 that ran like a top right out of the box...well with a little fine tuning.

My point is that Supertiger probably has good designs that occationally suffer from poor quality control. With that in mind, I'd rather not gamble with that brand any longer.

BTW, if you get a Supertiger, be sure to check for metal filings where the carb attaches. Both my 51 and 61 had a large shaving in there....looks like it came from when it was drilled for the hole where the brass carb retainer bolt goes. I got this heads up from sombody else who experienced the same thing.

Wiz

My experience with the ST engines is quite the opposite of yours, I have three .51s a new .61, an ancient G21-.46, a .40 and .45 and just about five minutes ago bought a .90 in Marketplace. None ever had any metal in them and are examples of machining excellence.