I just got my Revo running with the Sirio 27. The engine runs good, but I am not sure how it should perform. I have another Revo that had the 2.5R Traxxas engine on it. Even though the 2.5 would not pull the front wheels off the ground, it would lift the suspension.

My Sirio will not even do that. It takes quite a while for it to get up to speed, but when it does, it runs great. The one thing I noticed, it blows a lot of blew smoke out the exhaust, through the RPM range. It know it is oiling well and I leaned it out a little. The bottom end did improve, but it is still very sluggish off the line. I don't want to go to lean on it. I don't think I am that far off from optimum performance. I have not messed with the low speed needle, much. I turn it in about an 1/8 turn. That helped a little, but not as much as I thought it would have.

Any one have any thoughts?