that's exactly what I am doing. I only idled through the first tank,but gave it small amounts of rev's. also I used marks massive mods run in oil. actually mark I did that,used the run in oil that is on 2 tanks on this motor. But on the second tank it was on the ground running,putting around. max 1/4 throttle. still makes that noise but as I was walking home from my studio it dawned on me that yesterday when I put that engine in I did not use the ole paper method. I did it by feel. so what I am thinking is I have my gear mesh set to tight. when I go back over I am going to check it. and if it turns out to be a tight engine then I will keep heating it up with my heat gun and keep doing what massive mods suggests. and that's what I love about this forum, we have newbies(me) and experts(mark) to exchange ideas. Had it not been for the gent that suggested I check my clutch I would have never given it a second thought.