Book says to check it while hot but I've checked it both ways and doesn't seem to vary any. Is there some reason for them telling us to do it that way?

 

Oil expands when it is hot and also it has been pumped back in the oil tank so you get an accurate measurement. As the bike sets some of it will leak down in the sump and if you check it cold and add oil, when you start the bike and it pumps the oil in the sump back in the tank you will be over full.

 

A superb answer Hexnut so I will just agree

 

Sounds good to me too thanks