rsieminski

Ok, nearly new engine, broken-in with Dar's 2-stroke break-in method, with maybe 10-15 tanks through it of 2.5%/20%(50/50) fuel. The tank and lines are brand new, with a scintered clunk. When I point the nose up, it leans out tremendously. More than any other engine, so I adjust the carb a tad rich in that position. This makes the level condition very rich. Fly and come back, and the plug is dead.

In writing this out, I'm thinking maybe it's a tank pressure problem?? Why so lean when I point the nose up? I went through 4 glow plugs yesterday, ouch!

w8ye

My Feedback: (16)

Is there a restriction in your muffler pressure line to the tank?

rsieminski

Not to my knowledge, but I will check when I get home. Would that cause the described problem? The tank is right behind the firewall, so it's no further away than usual.

w8ye

My Feedback: (16)

Blow through it in both directions. Make sure it is clear

C185Pilot

My Feedback: (25)

I had an engine that did something similar...drove me nuts. After trying everything for some reason decided to but an piece of fuel line on the muffler nipple and blow through it...couldn't do it because it was blocked. Ran a piece of wire through the nipple and cleared it. The engine ran fine after that.

Mike

rsieminski

I blew through the muffler vent, tank lines, pressurized the tank, inspected all the new fuel lines, loosened and re-tightened the head screws. We'll try it tomorrow and see ig inadvertently fixed it somehow. Everything was clear by the way.

Could it be detonating? It's got like no nitro. I'll throw anothe .004 head shim under there. That would not explain the nose up extreme increase in rpm though. Just thinking out loud... It's got to be lean somehow. Before break-in, I dissembled, cleaned, and rtv-ed everything. But then again it's got to be something with that tank. It's about 2 1/2 in away. That's never been a problem before.