TexasAirBoss

My Feedback: (22)

I have an OS Max 61 on a Chipmunk.

I can't get a consistent idle in all attitudes. The idle was too rich. The motor died if I held the plane nose down at an idle. So, i leaned the bottom until it worked. But the next day, it did it again. I leaned the bottom a little more. In the last two days I have leaned the idle more than a 1/2 turn. And sometimes it still tries to die at idle in an inverted glide of more than 10 or 15 seconds.

Tank too high or low ? Carb flaw ? Anybody else having trouble tuning their OS 61's idle ?

Oh, I have a Bisson muffler, but it seems to provide good pressure.

aerowoof

if you have a low tank position when uprght this becomes a high tank position when inverted and can cause the engine to richen up at idle.for your purpose the centerline of the tank should be in line with the needle valve.that way the head pressure of the fuel level remains the same upright or inverted.also your clunk should be about 3/8" away from the back of the tank.

TexasAirBoss

My Feedback: (22)

Thanks.

I healed itself. I think it must have been varnished up a bit. I flew it 3 days in a row, and now it seems fine.