So I decided to drop the engine, don't ask why, I don't really have a proper answer just a few niggling feelings. I've slowly been adjusting the mixture screw to get the following plug colours Horz Vert Just wondered if anyone had any comments about the pistons and heads. Last few rides have been sort, I have not been checking the oil as I should have and thought when I came to remove engine it looked a bit low. Bore dia and piston clearance ok, top and middle ring end gap on upper limit as was the oil ring. Cheers Gaz
That look normal for one of these engines comparing to all the 900ss engines I’ve stripped down, some are clean around the squish area and the thick carbon build up on the pistons just like yours
