What kind of run should I be trying for with a Brodak 40? it's on a Vector 40, uniflow tank, full factory muffler which I have to use, 11-4 MAS and stock venturi on 5% fuel. It's got enough power I've been running it in a dead 4 stroke through the beginner pattern but sometimes it goes too slow. If I lean it out to try and get it to 2 stroke under load it just runs away and never cools off again. Thanks for any help.
MM
Did you break it in? Mine run "funny" for the first 10 flights or so.
11-4 is perfectly fine size-wise but you need to make sure it's balanced. Plain bushing motors misbehave when prop is oob and MAS are always guaranteed to be OOB.
Can you check your fuel line or NVA for any particles.
As a starting point, B40 should to be setup like a classic stunt engine: it needs to keep switching between 2 and 4 cycle. About 1 second in 2, 1 second in 4. When the model is released for take off, the motor will go into 2 cycle for about a lap or two until the model gets up to flying speed.