After reading posts about using the Tower Hobby muffler I tried in on a OS 46AX.

My flying time went from over 15 minutes to under 9 minutes. []

The Tower muffler has a small amount of additional power over the stock muffler and turns a 11x6 prop at 12,800 instead of 12,400, but it's not worth it to me. I would rather fly the additional 6 minutes!

My advice is stay with the stock exhaust. It's tuned for the engine and preforms better.

what are you running wide open with a 4 oz tank? I have a beer bottle on my magnum 46, and I can fly for about 20 minutes.

The muffler is not the problem, you probably just have it tuned too rich. I have the tower pipe on my os55ax and it gained 600 rpm and I've gotten 15 minutes flights out of a 8 ounce tank. The pipe is lighter, makes more power, and isn't that much louder than stock. It's a win win win combo. I will buy your tower pipe off you if you're sure you don't want it.

Mike

15 minutes with a OS55 and an 8 oz Tank????? Are you running this 1/4 throttle?

That's not off for a properly tuned (non racing ) engine.

The OS AX .55 should consume under .6 oz/min at WOT.

The muffler used has nothing to do with it, as it only has a minor impact on fuel consumption.

The engine does require re-tuning though, so it is conceivable that adjustments, etc. cause it to eat more fuel ( most of which goes UNBURNED out the muffler ) causing the decreased run time.

I just went through this with a new GMS .76.

With the engine out of tune ( new ) running rich, I got a wopping 5 minutes out of a 11oz tank at WOT.

After breaking in and re-tuning I now get 16-17 minutes on a 12oz tank at WOT. The engine is now consuming what it should.


GMS makes the engines for Tower, and the mufflers and carbs are identical.

Nope, this is on a 4.5 pound 3D plane. I suppose full throttle circle flying would drain the tank quicker though.

Mike

I get 20 min easy on a Magnum 46 with a beer bottle muffler, 8 oz tank. I think I'd probly use fuel a lot quicker at WOT but I don't fly like that.