Opinions on GMS and Magnum engines?

Howdy all,

Anyone have experience with GMS engines and care to comment on them? I'm specifically looking at the .25, .32, .40 and .47 models. Seem to have very nice power output for the price and a decent weight as well.

Also looking at the Magnum .28 and .46. Any opinions and real-world experiences with them?

TIA,

Doc

Reply to
"Doc"
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GMS are real bargains. You will be hard pressed to find engines in their price range that are better overall. They are at the top end of the power range (MUCH more powerful than OS or Thunder Tiger) and they are reasonably well built. They run very well on 5% nitro fuel but tolerate 15% quite well.

Reply to
Paul McIntosh

On Sat, 10 Dec 2005 10:22:57 -0700, "Paul McIntosh" wrote in :

I have a GMS .32 and a .46.

I've been quite happy with them.

Maybe a little trouble getting them to shut down by closing the throttle--but that may be because I haven't done due diligence in setting them up properly.

Marty

Reply to
Martin X. Moleski, SJ

Had a Magnum .40XL. Worst piece of crap I ever had the misfortune to bolt to a plane. Great success with their 4 stroke engines tho. I have several GMS engines and they ran great after very little break in. I am currently running a GMS .32 on a Pizza Box Flyer and its a real screamer. Ran a .76 GMS on a couple of planes and it also ran great. I would go for the GMS .32 over a .25. Same size mounting wise, lighter and more power.

Reply to
Fubar of The HillPeople

Howdy all,

Just got in the Magnum 46 from tower. Went right to work, after two tanks idling reliably. Bought Magnum 40 in late 80's, lots of power. I flush them out before use, make sure there's nothing that could cause problems. Price was right @ 59.99!

HTH

Rik

Reply to
rik street

A friend runs several GMS and some other members have a few. The 47s are real sports engines with very good high end power. The series II engines are a huge casting improvement on the series 1, I had to chance to compare a selection of 47 engines from both series.

Biggest complaint seems to be an idle you can't kill. Apparently (so the story goes) the carbs leak enough air that it's hard to get them to cut off when you want. Personally, that's not such a bad thing compared to having the opposite occur.

Friend with the 47 loves them because they are cheaper than OS and make almost as much power as a 46AX.

A club member with a 32 says they outpower most 40s but admits the engine is a bit of a screamer and may not be suited for trainers.

The 4 strokes have a wonderful reputation here. I guess it could be summed up as "OS on a budget". They are quite powerful and highly reliable coupled with a good price. The two strokes also have a good reputation but I'm only aware of one Magnum 2 stroke in our club compared to the 20 odd Magnum 4 strokes..

Reply to
The Raven

I have a GMS .47 engine as well as O.S. .40 FX and .46 FXi engines. I recently had a chance to purchase a Magnum XLS .52 from a LHS for $55, but I haven't run it yet.

My O.S. .40 FX and .46 FXi are smooth, reliable, and powerful. My GMS .47 engine is more powerful and transitions better than my O.S. .46 FXi. My only complaint about the GMS .47 is it's noticably louder than the O.S. .46 FXi.

I won't hesitate to purchase another GMS engine in the future. My first one has been absolutely fantastic. I have my radio programmed with a kill switch for the GMS-equipped plane, and it quickly shuts the engine off without incident. I haven't experienced any problems with "air leaks" on the carb.

Hopefully I'll get a chance to run the Magnum in the not-too-distant future. If you're thinking about buying a GMS engine, I'd advise you to give it a shot.

Reply to
Ed Paasch

Just come back from a day of flying a pair of 25 GMS in a self designed multi. Worked just great.

Reply to
johnyh

Thanks everyone for the great responses! Looks like the consensus on GMS is "go for it"! Gunna grab a few here shortly.

Doc

Reply to
"Doc"

I have a GMS 47 that runs like a dream on anything that is not moving. I screwed with it for a couple of years on a plane and NEVER managed to get it to stay running for a whole flight. Quite often it would die on the takeoff run. I pulled it off, tossed it in a corner, and put an OS 46 FX on it which has died in flight ONCE in two years.

good luck on your choices.

bob

Reply to
Bob Cowell

Bob,

Is yours one of the remote needle models? The Tower version has the same characteristic. I have flown several of the standard version GMS engines and they all performed very well.

Reply to
Paul McIntosh

No, It has the needle on the carb. it performs flawlessly as long as the plane can't move, set it free, and the troubles begin. I think the &*^% think has some form of motion sickness

Reply to
Bob Cowell

On Mon, 12 Dec 2005 07:25:06 -0600, Bob Cowell wrote in :

This is the funniest post we've had in weeks!

I'm gonna cut that out and save it. :o)

I inherited an OS .91 in an UltraSport 60 that showed signs of motion sickness ($150 for the plane and engine). I crashed the plane before I figured out what was wrong. Haven't tried the engine in another plane yet. :o(

Marty

Reply to
Martin X. Moleski, SJ

Hmmmm Seems like every manufacturer puts out a lemon once in a while. I have a Super Tigre .51 that runs like a demon on the ground but about 5 min into any flight I get ready to deadstick. Mid range is often a little weird too. It acts like it's loading up but if I lean it out (yes I tried combinations of low and high idle screws) it often won't keep running at all. Personally I think it's a bad carb but ST won't own up to it. They just tell me to keep running fuel through it until it's broken in. I think a gallon is enough. Thought about putting a Perry carb on it but it breaks my heart to put a $35 carb on a $79 motor. Still cheaper than a new plane I guess.

--Mark

Reply to
Mark Eastman

You do know that that carb also has a midrange adjustment? You twist the spraybar I think. Been a long time so as a ST owner.

Reply to
Sport Pilot

Also, I think that is a ringed engine. Many ringed engines are just starting to break in with one gallon of fuel. I have had engines that didn't settle in for well over a gallon almost two, and took several more before they made peak power. On the other hand I have had ringed engines that have broken in (to the point that it would run reliably) almost as fast as an ABC type.

Reply to
Sport Pilot

If the engine can run fine for five minutes, it is not the engine that is the problem. It is either your settings, vibration/fuel foaming or your plumbing has a problem. Engines do not come with timers.

However, you can rest assured that if you fly it repeatedly in the present condition, you will have an engine problem shortly because you have burned up the engine.

Ed Cregger

Reply to
Ed Cregger

You only have one gallon through a ringed engine and you expect it to be broke in? Mine took almost three gallons and then it was a pure demon!

Reply to
Paul McIntosh

This is precisely why I tend to steer most newbie folks toward non ringed engines, Paul.

Any day now, I expect one of the big R/C marketers to begin offering pre crashed models for sale. For folks that just don't have the time to actually fly them.

No reflection on the original poster intended. Just a comment about our culture.

Ed Cregger

Reply to
Ed Cregger

any one know what the idle vavle is suposed to be set at from th

factor

-- jmys

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