I Have a Tower 46 and a GMS 76.Both run fine on the ground but quit in the air for no apparent reason.I have checked the clunks and changed glow plugs but no help.I have 3 OS engines and no problems at all with them.(Is there a moral here?)Does anybody have any sugestions other than the trash can?

I'll give you $60 for them both. Don't waste your time with them, they have hard chrome sleeves, and take a long time to break-in, especially the GMS .76. Not worth the time. Sell them to me.

How much fuel is through them?

You can just send them to me for free. We won't bother with the paper work.

Enjoy,

Jim

If you don't want to sell the engines or give them away, you will need to supply some information and maybe answer some questions.

1)Have you run the engines enough to break them in?

2) Have you adjusted the high speed needle valve correctly? If you not sure how to do this there is an abundance of information on how to do it. Search this site or ask someone with experience to help.

3) Same as 2 for the idle mixture.

4) What is going on when the engine stops? Are you at full throttle and it quits? Are you advancing the throttle from idle to full?

5) Fuel being used? Props?

Put some information here and you will get help.

Good luck.

You get what you pay for ? ever heard that One? At the Field every body has one word for a GMS it's EBAY !!!!

Yes, there is a moral to the story. You must burn Chinese fuel in Chinese designed and built engines.

The fuels that run well in OS engines have a percent or two of soy sauce (Japanese grade) in them. Obviously, there is a missing ingredient that Chinese engines absolutely need that is lacking in your Japanese fuel.

The simple solution would be to sell them to some other unsuspecting person, just as they were sold to you. What's fair is fair.

No longer support RCU

Artisan, You kill me!! Soy sauce??? Everyone knows it's not soy sauce....It's rice wine! Soy sauce won't burn good and leaves a lot of goo.
Suptter

Buying a GMS engine is like going to Vagas putting your money down and Hope you win !!!! and usually the odds are against You!!

No wonder I couldn't get that POS Fox 40 to run right. I was missing some of that Kentucky moonshine.

I have owned 2 gms 76's and they were both great runners but required a lot of needle fiddling for the first 2 or 3 tanks. the 76 likes to be run on the rich side and a tuned for max rpm the engine will run lean when the tank drops below 1/2 full. richen it up and by the way I still have a brand new muffler for a gms 76 I would sell reasonable if anyone needs one

I bought an A.S.P once... (do they mean wear out a.s.a.p ?)

I experienced conrod clicking before i got it runned in.

No jokin at all. After 12 hours of running, it was so badly worn out that main bearings started to whine because of alu-flakes from the jack-ass conrod being rolled in.

When piston started to chew on the back-plate, I decided I did not want to risk my loved model with that engine anymore...

The dealer hided, telling me to contact the distributor, tight lad, huh...

Well, guess I was too but I did not think I wanted to spend another 50 bucks at that time...

Guess what the distribtor says ?

Distributor: What fuel did you use ?

Me: 70% Methanol, 20% Castor-oil, 10% nitromethane, according to instructions. I purchased it from the most known manufacturer in my area ( I did not mix it myself).

Distributor: You might have ruined your engine by using castor, its well known for doing that.

Me: that was the most stupid thing I've ever heard!

Distributor: I have competed in Pylon-Racing for XX years and I know what I am talking about !

Me: oh !, goodbye.. (Twat!)

I made atopsy on the cadavre... conrod had 0,3-0,5 mm play at both ends. Piston had worn out conrod bolt bearings as well, severly.

Conrod looked like molted tin quenched in cold water...Not from wear, but from craftmanship...

And It had bite-marks from holding it during drilling/reaming, that
was so deep so it was bent from it.

Connecting rod was very soft and bronze bushings was glaring with their absence...Cast from surplus cooking pots ? Well, nothing wrong in that as long as a good formula is maintained.

One extremely strange thing was that the engine looked quite nice otherwise...

One other thing that was bad was that the carb sucked air from nowhere, making it hard to adjust. (engine still ran for 5 secs with throttle fully closed, no visible air-passage at throttle-drum).

Had a LOT of different engines before but not like this. It was like the toys from same source they sell at the mall...

I used lots of different engines for many hours before, without any appearant signs of wear, not only O.S. but also the other well known brands.

Sticking to the old brands for now on.

Cheers,
Ikaros

Suddenly quitting in air without overheating or seizing, does point at problems with fuel feeding or glow plug.

Can happen with any engine...

Some engines requires different plugs than others of same size.

Other engines sucks fuel better than others (less throttle area and sligthly less h.p. perhaps?) and works with less than ideal tank installations.

Cheers,
Ikaros

Get rid of those cheap engines! TH, GMS, ASP, MDS... all cheap engines! Sell them to me cheap, I'm making a wind chime for my kids room. With all that cheap aluminum, it ought to sound sweet.

Never had a single problem with a cheap engine. Sounds like your engines may be a little more sensitive to tank fuel level and you should probably experiment with slightly richer settings on your highend needle and low end.

In fact, set your high end 300 rpm shy of max lean rpm with a tank level of 1/4 tank.

what are you guy's on about any cheap motor will run the same as a good OS etc. All you have to do is run them in right if you can not do that you are all a bunch of old woman. I have had many ASP motor's and OS motors and they have run very good.

Man! That's one of the most thorough disassembly jobs I've ever seen!

Looks like he got mad at it and put it in the rock crusher ?

Jim

I have seen nothing but good runs from GMS engines at our field.

I had a GMS .47 and it was strong! But,,,, it would sometimes die in flight when I reduced throttle from hi to low. You could even hear it wind down. It was like the glow (ignition) was removed! Just like when you ground the plug on you mower etc. No plug change or fuel line/tank change as well as hi/low adj helped. I was very impressed with the power, but the reliability was lousy.

ZB

You need to come to my field then!

Doug

There are lots of problems with GMS at our field.

There are no problem engines, just problem engine tuners.....

[sarcasm]Thanks for that bit-o-wisdom. Any more earth shattering revelations for those of us that have it all wrong, and have mistakenly believed for years that there actually IS a difference in quality and craftsmanship among engines?[/sarcasm]

I'll say if you can get a Cheap engine to run properly (no dead sticks/lean runs), good for you! There are those of us that would rather go to the field, tweak the needle and fly for the day.there are plenty of those at my field that enjoy playing with the needles instead of flying. Please understand, I'm not putting any one down for that! I for one enjoy running an engine that was well designed, well manufactured!

Doug