sk8z27,

I know that about the 2.5R engine on my Revo. Our track has a 120ft straight. The engine has no problem reaching 2nd at about 1/3-1/2 that length. It keeps up with most of the other trucks, and for those that are faster I get them in the turns. I do appreciate your words on that though. I was actually asking about my OS engine.

I've been tinkering with it (my OS) for 2 days now and am having major problems. There's no power (doesn't reach second in my TMaxx) unless I lean it out so much that it gets over 300. Then it's literally smoking. There doesn't seem to be a happy point. It's either 220 and puttering, or 300 and smoking, but flying. And that's all within about a 1/8 turn. You're probably thinking "only turn it 1/16", but trust me I've been there. Can't find that happy place. This is the way it's been since I got it 3 years ago.

I don't think it's an air leak, as the engine's hardly been run and I just replaced the exhaust coupler and reseated the carb.

I think I'm gonna have to give up and replace it, unless you can tell me what else to check.