Campgems

That orentation is hard to tune. Espically if the engine is running a bit rich. Oil puddles in the rocker cover and until the engine gets really warmed up, there is excessive oil being pulled in the valve guides. I have an O.S. 52 that was installed like yours that required the glow diver untilfor at least two minutes of running before Iattempted to fly it. This was on the first flight of the day. After that, it was just fine.

Tuning the carb though sounds like your major problem. Here is what Iwould try first.Ifyoudon't have a bench mount for you engine, throw together oneand get the engine running wellin a head up orentation. thenback in theplane and refine the adjustment as needed.

Tuningthe carb is a balancing act. Either needle too far from optimum will cause the engine to run OKat high butbadly or not at all belowhalf throttle, or run at idle but not well athigher RPM.

This is the sequence I use and has treatedme well.

Set both needleto the inital setting in the manual.The high speed is 2 to 2 1/2 turns out from closed at 1/4 throttle opening. Set the mix control per the instructions in the attached photo.

Now, with the engine running and warmed up a bit, and the glow driver off,open the throttle to full, and slowly lean the high speed for maximum RPMthen go to the rich side by 300 to 400 rpm.

Adjust the throttle to the lowest setting that will allow the engine to keep running and then without the changing the throttle, slowly lean the idle mix for maximum RPM.

Go back to full throttle and again adjust the high speed needle.

Back to idle, this time the idle speed should be considerably less that the first time, but again set the throttle to the slowest speed that will keep the engine running, and again very slowly, IE1 16 turn at a time, and remove the screw driver after each adjustment, adjust for maximum RPM.

Now work on the transistion. Run up the engine then go to full idle and let it run for 10 seconds or so the jam the throttle full open as fast as you can move the stick. If the engine dies, open the mixture screw 1/16 a turn and try again. If it bubbles and slowly gains RPM, then go lean on the idle by 1/16 turn and try again. The engine should jump from full idle to full throttle in less than two seconds. One second should be your goal.

Now, with the engine back in the plane, go through these adjustments one more time.

Last, on the valve adjustment, At TDC with both rockers loose, a 0.002" feeler should go freely between the rocker and valve stem, and a 0.004" feeler should be tight. This is on a cold engine.


The manual can be found at this linkhttp://www.rcuniverse.com/forum/m_10192403/anchors_10192403/mpage_1/key_/anchor/tm.htm#10192403

The pages are upside down,

For some reason I can't post the photo of the mix control inital setting, but it is on the third page of the manual on the above link.

Hope this helps

Don