GMS Engines - Page 2 - RC Groups
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Mar 02, 2007, 01:13 PM
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matthew954's Avatar
Artisan, sorry I am just now getting to your question. The wonderful world of work and video games lol. Has been a few days since I have logged on here at rcgroups. I have been thinking of building a 1.20 sized Ultrastick using the Ultraspadstick directions at spad to the bone. I wanted a good fairly cheap engine to power it with. But having heard many good things about the G2300, I think thats the direction I want to head in. In regards to your question of what an Agriduck is here they are. These pics came from the website of the manufacturer.

www.mudduckaviation.com

It has a wingspan of about 108" if memory serves. And flies about 15-20 mph at full throttle. Depending on the engine you use. I have the high wing version on my build stack now and plan on buying the plans for the agriduck this summer. I have both planes for Clearview RC Simulator and both fly great. Lazy sunday flyers, mixing fun and relaxation. Their motto is "Build fast, fly slow". Anywho this is the Agriduck.
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Mar 07, 2007, 12:16 PM
Registered User

GMS frustrations


I have a GMS 61 which went in my Hobbistar 60 trainer. All last year nothing but frustrations - it ran great on top half of the throttle, but too many times it would transition down to idle. I had some deadsticks - good training I guess. This year in preparation for the spring I could not get the engine run at idle or to idle down. The low end idle needle always seem very easy to turn - and we (flying buds) figure that is and has been the troubling issue as the needle probably moves with the vibrations.
Anyway no recommendations are coming from me and yesterday I went and picked up a new Evolution 61.
cheers,
Beerboy
Mar 07, 2007, 09:48 PM
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matthew954's Avatar
I almost bought an Evolution 1.00NX the other day. Yeah I know sheer overkill on a Mud Duck, but it would sound cool. Not to mention the extra power could come in handy. My LHS has them in stock and with my x-mas gift card I can get it for 110 bucks, instead of 160. I did notice a GMS .25 sized engine. I wasn't impressed by the way it looked. The only other two in the display case that would fit my plane was the Evo 1.00NX and a Supre Tigre 2300. And the 2300 would DEFINENTLY be overkill. I want the 1.00NX, although my mother would shoot me if I brought it home lol. The drawbacks for still living at home lol.
Mar 10, 2007, 10:17 AM
Registered User
The first GMS engine I bought was the 120. And I love it. Put it in a 120 great planes supersportser, and wow did it go .... then I bout a 74 and installed it in an old patternship I got, that was designed to run with a 61 rear exhaust and a tuned pipe. I let one of the original designers of the plane fly it, and he said that it has as much power, if not more than the old os 61's had that the plane was designed around.

Both engines have run great, right outa the box, and tons of power, and no problems. And both idle like a dream. And will throttle back enough to kill em too.

Just bout a 61 and can't wait to try it too.

the 120 will run on both 5 % and 10% nitro, where as the supertigers don't like nitro.

And the only problem I have had, is with the 74 and that was the muffler comeing appart in flight. Lock tight fixed that problem.
Mar 29, 2007, 07:31 PM
surfmount
I have two GMS .47's and a GMS 1.2 that I bought from MECOA with their
trade deals. I got the 47's for $50.00 ea. with two old motors per engine
and the 1.2 for $80.00 with two old engines (I have a lot of old engines).
They are all fantastic engines. The 1.2 gets 9100 RPM on a 16\6 APC.
That is at Denver Altitude. The only neg is with the steel sleave it is
on the heavy side.
Surfmount
May 23, 2007, 01:44 PM
RMS
RMS
Registered User
RMS's Avatar
I just got interested in the GMS 1.20 and found this thread. I also found that mecoa.com (K&B), is offereing trade-ins. If I send them my old Enya .60, they'll send me a new GMS 1.20 for about 88 dollars. I have to go for that one!

Hope I have good luck with it.
May 25, 2007, 05:51 AM
Registered User
I bought a GMS .47 from Tower and flew it for a year without any trouble. It had tons of power, idled good, and transitioned great. The next spring, I took it out to go fly it and didn't check the cylinder head bolts. They were loose and I couldn't get the engine to run right (obviously). Retightening the bolts didn't seal the head, so I ordered a new cylinder head gasket and that stopped the fuel leak.

I tuned it back in and got it running really good again, but then the crank broke while I was running it in on the ground. The popular theory for this is that the crank overheated when I was running the engine with a leaky cylinder head.

Hobby Services, the folks who handle O.S. and Super Tigre warranty issues for Hobbico, also handle the GMS engines for repair/warranty. I shipped them my broken GMS .47 along with my receipt from Tower Hobbies on a Friday. The very next Friday I got a knock on my door. It was UPS with my brand-new-in-the-box GMS .47 that they replaced it with.

Great engines, great warranty service. Just make sure you check your cylinder head and backplate bolts once in a while!

I would happily buy another GMS engine if I felt it were a good fit for a particular project.
May 26, 2007, 08:48 AM
Registered User

GMS 1.20 problems


I have a new GMS 1.20 that I am trying to break in. It starts quick runs for about 1 minute and dies cold. I have to low speed needle at factory setting and the high speed open about 1.5 turns. It has the same results at any speed. low idle, fast idle, 1/4 or half throttle. Haven't gone any higher than that.

The engine sounds great, smooth running then poof. Nothing. Like you pulled the plug out.

It will start back up and run for about 20 seconds right away. Give it 5 minutes and it will run again for a minute.

The very first run it ran for 8 oz of fuel at 1/4 throttle or less and it did the started cutting off.

Any ideas?
May 26, 2007, 09:43 AM
Registered User
Quote:
Originally Posted by dr_d_2k
I have a new GMS 1.20 that I am trying to break in. It starts quick runs for about 1 minute and dies cold. I have to low speed needle at factory setting and the high speed open about 1.5 turns. It has the same results at any speed. low idle, fast idle, 1/4 or half throttle. Haven't gone any higher than that.

The engine sounds great, smooth running then poof. Nothing. Like you pulled the plug out.

It will start back up and run for about 20 seconds right away. Give it 5 minutes and it will run again for a minute.

The very first run it ran for 8 oz of fuel at 1/4 throttle or less and it did the started cutting off.

Any ideas?

I have a 1.20 that had the same problems, it would run for a minute or two then just quit. I think it's just that it's not broken in yet. They seem to need more time for breakin than other engines, perhaps being a ringed engine makes the difference. Give it some more time, you'll love it. We also found that running low nitro fuel, 5%, seemed to help the problem.

Perry
May 26, 2007, 10:10 AM
Zor
Zor
Suspended Account
Quote:
Originally Posted by juice90
where as the supertigers don't like nitro.
Why?

A statement without explanation.
I would appreciate to know why.

Zor
May 26, 2007, 03:58 PM
Registered User
Quote:
Originally Posted by Zor
Why?

A statement without explanation.
I would appreciate to know why.

Zor

Some engines designed in Europe are made to run on no or low nitro fuel. It is evidently very expensive and hard to come by. Supertigre and Rossi for example.

Perry
May 26, 2007, 04:25 PM
Zor
Zor
Suspended Account
Quote:
Originally Posted by 4hubbards
Some engines designed in Europe are made to run on no or low nitro fuel. It is evidently very expensive and hard to come by. Supertigre and Rossi for example.

Perry
Thanks for the reply Perry,
Like my engines, I breathe better

Inhale //// ---- \\\\\ exhale

Zor
Dec 23, 2008, 02:16 PM
Registered User
How would the gms .76 compare to the saito 100 power wise?? Thinking of putting one in a mojo .60
Dec 28, 2008, 01:32 PM
Registered User
Can't speak for anything larger but the 40 and 47 have impressed me. Throttle transition is as good as anything I own and the 40 is especially stingy on fuel. After many gallons of fuel they still have very good pinch and being of the hard chrome brass cylinder variety I suspect they will stay that way for a good long life. Just my two cents.

Zor, I am with you on the Why. My tigres run great on 10% nitro. On my 40 and 45, if I am going to run 0% nitro I take out the head shim. Actually, on the 40 I have a different head that I have machined to increase the C/R to roughly 13:1 for running no nitro fuels. Haven't done one for the 45 yet but I'm sure it will respond good as well.
Last edited by Jezmo; Dec 28, 2008 at 01:37 PM.
Jan 05, 2009, 06:42 AM
Airhead
teemuki's Avatar
We found a good use for 1.20 GMS engines. Although we haven't had any problems with them in rc use, we figured those golden heads could suit well in other applications as well.
Behold, the twin engined ice sled.
Twin Model Engine Powered Ice Sled (4 min 5 sec)

props are APC 18x6 Wide.


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