I have 2 os 46 ax engines. both run beautifully. run in as per specs and field recommendations of club guru's
one is dry as a clam in the exhaust department (that is, not too much oil spit)
the other is a greasy mess, with exhaust discharging oil all over the place, and the muffler leaks both at the manifold and from the lock nut.
after a flight, my plane is as greasy as a pig in s........
seems like one has gaskets and the other doesn't (BUT NEIITHER HAVE ANY MANIFOLD OR MUFFLER GASKETS?)

have tried leaning out low end and high end to no avail (since they both run great with very similar settings)
so what gives??
Any comments or suggestions would be very appreciated
Sure I'm missing something obvious, (or just done something pittifully stupid??)
Many Thanks
DB

It's possible that the airflow over the two different models affects how the exhaust residue gets scattered. If you have a lot of residue, it's not from leaky muffler seams. They could not make a big mess. If the muffler is just getting coated, then it could be a leaky seam, however, it's not a point of concern. The mufflers are assembled without gaskets, and the fit can vary a bit from one to the other. Some leakage is normal.

thanks Bill,
one model is a trainer with exposed engine (Avistar).
the other is a Pulse XT with partially enclosed engine (but mosty the HEAD AND MUFFLER ARE EXPOSED TO AIRFLOW)
so I'm still not clear on why the Pulse gets so totally covered in oil rsidue and more importantly
how can I remedy the situation.
Thanks in advance for your advice.
David

If you're talking about the airplane getting fuel residue all over it, then that's another thing. THAT would also be considered completely normal. That's because there's a lot of oil being thrown out of the exhaust port of the muffler. The airflow around the airplane then takes over. You can try adding a tube to route the exhaust farther away from the airframe, but this may also add enough back pressure that the engine will slowly overheat. You can't tell if that will happen until you actually try it.

For years, it's been considered normal to have to wipe off the residue from the airplane. I've had models where you had a large, dark coating of fuel residue all down one side of the model. You'd have to use a few paper towels to wipe it off before you could use the cleaner to get the rest off, it was that thick!

As long as we run glow engines, we'll have fuel residue getting all over the model. Completely normal.