Kinda glad for this post too because I'm in the middle of breaking in my new Saito 125. I'm doing it in my garage with with the exhaust pointed out the window,lol. Still I noticed that with the first few 8oz tanks I ran through it at idle or just barely over,the motor never heated up much more then room temp. Now that I've got about 6 or more small tanks out of it at an extremely rich mix I'm starting to rev her up more to sometimes 6 thousand rpms for a few seconds at a time to try to get some heat out of it. It still doesnt heat up much at all. Its still no problem to hold your hand on it after the run. The pipe gets fairly hot,but thats it. Is what I'm doing ok? And now that I've got about eight,8oz tanks through it at colder temps,when can I start to think about taking it wide open for a bit?