I notice on the B-17 I bought off a fellow last year, that he does not have mufflers on the pipes off the 26's. Which also means there is no line from the exhaust to the tank. The engiens run fine this way on the ground. Never flew it yet.

So now I am setting up another plane with this same engine. I have a combat P-51 from GP and have a new OS26 for it. I am wondering this, should I put the ehaust line on this plane? Can I go without it? I would rather go without if possible for cowl cutting reasons. Would be nice to have just the little pipe stuck through. Also, when putting the filler line in (using a Tee) the fuel line, will it flood my engine if the throttle is opened while fueling? Someone asked me this and I was unsuure, but thought it was a good question. So I asked you guy's.... Any advise appreciated.

Kevin

I had one of these for a few years.

I took the muffler for I couldn't hear the engine over the cars going down the highway a quarter mile away.

The engine drew fuel fine without the muffler

The engine is not loud in the air without a muffler and it draws fuel fine in flight without the muffler

Leave the muffler in the box.

When filling up the tank, have the throttle fully closed or fuel will run into the carb instead of the tank (path of least resistance). I have 2 of those, sweetest engines out there

Thanks guy's. Not sure how but I have 6 of these now. 4 in one bird and 2 on bench....one of them new in box.

Finishing this one up now.

Kevin

Its easy to have many FS26, they're so cute! I'll probably be getting me another one soon

Oh yeah...one more question. I had ran 15/18 wildcat in my other 4 in the B-17 on the ground but never flew it as stated. I have no idea if this is a good fuel for this engine or not. What do you guy's run in yours, nitro percentage wise.

Kevin

Same fuel Just perfect

I run them on 0% or 5% nitro. I wouldn't use more than 20% nitro on them, especially on larger props. These engines have a compression ratio of aproximately 8:1. I've ran mine on 5% fuel at a compression ratio of 12.6:1 with no ill effects. See here

Sounded great! That was on 5% with the 12.6:1? Thats great news. I have 4 gallons of 5% and 8 gallons of 15%. Almost done with the P-51. I am liking this engine already.

Kevin

My OS 26 was easy to tune.

Go to the field - start it - and fly

It was NIB when I got it. Ran a 10-5 APC mostly

So which needle is the low speed needle? It is running real rich on the bottom end and doesn't seem to matter what I do with the hsn. It seems like fuel is pouring out of the weep hole near one of the screws. Maybe a air bleed screw? Not sure how these little ones work.

Kevin

This engine has an airbleed type carb.
There is one screw on the carb next to a small hole. set the screw so it covers only half the hole as a starting point. Unscrew for leaner mixture, screw in for richer mixture.

Follow the manual's procedure, it's very simple. Here.

Hi!
I use two of these engines in a Marutaka DC-3.
No silencer pressure used. Throttle is instant and engines are very reliable.
I use 5% nitro and 15% all synthetic oil (like most other fellows do over here).

Props are custom made, 3 blade ,carbon fiber 10x5 props. Rpm with these is around 9500-10000rpm.
Tanks (110cc) are tin. Set-up with Uni-flow.