who makes their engines? im gonna guess its O.S. being that GP is the primary distributor.
if not, are they any good, im looking at building a Hobbistar 60, and the Tower hobbies BB61 looks good at $90.

the parts all are closest to the gms engines

gms makes them

i have a gms .47 and it runs really well. (i have also seen a few at my field and they run well also)
i just bought a gms .32 ill see how it works.

their good powerful engines. and for the price i would buy them over a OS AX of the same size any day

I bought a Tower 61 awhile back to put in a half built plane a friend gave me. I didn't really want the plane and got the Tower because it was the cheapest engine I could find at the time. Started on the first flip and proved to be one of the best engines out of the 2 or 3 dozen I've owned. Powerful, reliable, and easy to start-at least the equal of my OS 61 fx if not a hair better.

This is interesting. I took a look at the Tower .61, GMS .61 and Hobby People's Magnum XLS .61, they're all just $89.99. I've never had a Tower but own .47 sized GMS and Magnum, and they seem like fine engines. I don't think you could go wrong with any of them. Solid power for the money. The gold anodized cylinder head on the GMS is pretty cool though.

The Tower, GMS, and Super Tiger Engines are all made by GMS

It was a rumor some years ago that Hobbico (Tower) owned a good share of the GMS company in China.

To examine the three brands of engines there are similarities. But I would caution about trying to mix parts between brands other than carbs on the GMS/Tower

The hottest seller and favorite for some 8 yrs has been the Tower 75. It is an excellent performer in the 60 class

Recently Tower has been selling the Super Tiger 75 and 90 at good prices. They are pretty much in the same size case as the Tower 61 and there has been a surge in their popularity.

The Magnums are not related and are made by Sanye near Hong Kong

I was training a guy last year with that same plane and engine, worked really well, plenty of power, the engine had most of the issues with the cheaper brands, but pulled the plane well-go for it.

Remember though-engines are like MANY things-"you get what you pay for".

Yup the Tower engines are real stump pullers.

Strangely, the GMS .47 produces LESS power than the Tower Hobbies .46, even though they appear almost identical.
Conversely the GMS .76 produces more power than the Tower Hobbies .75, even though they too appear almost identical.

One nice thing is that you can often ( but not always ) interchange parts between the GMS and similiar Tower engines.
This makes it a bit easier to find mufflers, screws, etc. that may be otherwise hard to find or sold out.

The original GMS 76 had a Dykes ring and felt like it had no compression to feel of it. But would run great.

About 5 years ago it was changed to a regular ring

The GMS 61 is also ringed

The Towers are all ABC.

The GMS 120 is very mildly tuned and is not the hot dog that the smaller engines are

awesome, good to know its a good buy thanks guys really appreciate it.

You may want to think about the TH .75. Basically the same weight and more grunt. My 75 is great!

Good call-more uses for the 75 down the road.