new engine...

[jon morse]

Hey there, new to this forum and dirtbikes in general...I just got my son an older rt100 for his first bike...the engine is in bad need of a rebuild so I ended up just getting an entire freshly rebuilt engine...my question is when I am placing the engine in for the first time is there any warnings or special considerations I should look out for when doing so? Thanks and sorry for the beginer question.

[ossagp]

hard engine to hurt. if it is already assembled and you dont want to tear it down again, I would simply get the owners manual for about any air cooled yamaha single and follow it. low throttle and cool it often is kind of the byline of that for the first several hours. I like short motocross courses to break them in on. if it still has the mix bottle on it, change it to fresh yamalube for premix and make sure the line on the pump actuator lines up with the one on the case when it is at closed throttle. then ride it.