ORIGINAL: strulag

Hi guys. Saito 150 owner. First 4 stroke (2nd engine overall). Not very experienced with engines but read as much as possible trying to learn. I even bought a DVD "About Engines" from Model Airplane (I believe).

The problem is that now I'm getting contradictory info and I don't know which one to believe. On the DVD the guy swears by the pinch test (up/down in rpm = rich, down/up = way lean, constant rmp = lean, up/stays there = perfect) and also on the smoke trail. On the saito.info site the guy says the pinch test as well as the smoke trail doesn't mean much and the best way to do it is with the tach. Peak it then bring it back 200-300 rmps. The problem with this is that the rmps never stay the same they jump around too much.

I kinda tried both and here's what I got. With a 17x6 APC it peaks at about 9400 and I took it back to about 9100. The pinch test however shows a lean condition (pinching the line doesn't do anything). Here I can tell the power is pretty good and I still get a slight smoke trail (I believe not at all times). When I go with the pinch test to the "perfect" condition (rmps go up and stay there) the rmps drop (I forgat exactly to what but I believe it's around) 8800-8900 the smoke trail is a lot more pronounced and at all times but the power is noticeably less. I would love to leave it at the 9100 rmp setting but I'm afraid that's too lean and I'm not leaving enough room for it to lean when the tank level is getting low??? I don't know...SO...where should I set it at???