Hi!
OK! Here we go!
The OS .46 AX is dead reliable if you follow these "rules".

Fuel tank placement :Tank paced so that the center of the tank is in line with the carb intake orifice when plane sits horizontal.
Tank size: 8-10 oz. Not bigger
Tank type: all R/C tanks. But best is a two clunk variant (Uni-flow system).
Tank position: As close to the engine as possible.
Best tank: Tettra "Bubbleless" .
Prop: APC or RAM 11x6 or 12x4 for most sport airplanes...balanced!
Glow plug: OS 8 or Enya 3. There are many others that will work but these are "the old standbys".
Fuel: 5-10% nitro and 15-20% oil, the rest methanol.
Engine mount: plastic or aluminum with engine bearers flat and parallel so that the engine crankcase isn't distorted when engine is bolted down. If you buy a plastic mount and just bolt the engine down you are making a big mistake! It must be filed !!
Spinner: Use a aluminum spinner nut or if you insist...a Tru Turn aluminum spinner. Never ever cheap plastic spinners without a backplate!!!
There you are.
Good luck!

"Tank paced so that the ........ in line with the carb intake orifice when plane sits horizontal." <- A Myth akin to the "fuel stays in the back of the tank" myth...


Its not really needed, else all of our engines would die in uplines and downlines... tank height predominately applies to fuel siphoning, preventing fuel from leaking out when the plane sits on the ground...

On most normal ARF's if you use the provide fuel tank position, even if you move or invert the engine, the tank height is a non-factor.

Millertyme2000, here is an update on my situation that may help you. We have worked on my new OS46AX on three different sessions. We started with checking for air leaks at the tank, replacing glow plugs, changing to different size props, numerous high and low idle adjustments and this is what we found the culprit was tonight. First, my new Sullivan tank cap screw was a little loose, the screw was stripped on the inside backing piece. Installed a bigger screw and it snugged right up. Second, the high speed needle valve was machined wrong from the factory and the where the o-ring seats it's too wide and the o-ring can easily be moved back and forth. Typically, I've seen snug fits on the o-rings and when they move or rotate easily it's time to replace them. I swapped out my hsn from an older OS46FX and we went over all the adjustments (low and high) and it ran fine. So, I need to order a new hsn valve or find a second o-ring that will fit behind the first. I was ready to take this engine off and ship it back to OS, but after two successful flights to near empty I think we finally found all of the air leaks. You might want to check yours, hope it helps. DG

Hi, Thanks everyone for all the help. Today I took it back out to the field and took it up and ran it and it just kept on running and never did die. I brought it down and it was almost dry. I flew 3 more tanks through it and never once did it even cut out. I think it was vibrating due to loose engine mount screws and it needed a new prop and the clunk was bounceing out of the feul and causeing me problems.

Hi!
The tank placement I talked about is no myth! Try flying a plane inverted with the tank placed low and you see directly what happens.
Most ARF planes (ie. Calmato ,Calmato sports)have the tank too low. Why! Design! Simple as that! Not functionality.
All experienced fliers know how important it is to have the tank placed correctly...telling people otherwise is just rubbish!