hi all I bought my old mans 1982 cb750 off him last year as a project bike with the plans of doing a complete rebuild on it. I have ran into some problems when it comes to the engine. I have removed the rocker cyclinder head cam chain tensioner and the one bolt that holds the bore to the cranckcase but just cant get it to come free. I have tried everything from tapping it with the rubber mallet, soaking it in wd40 jacking it up with bolts, rotating the crank to try and lift it with the pistons but it just won't budge. the pistons are free and move up and down the bore so its not seized in that sense. has anyone got any ideas on how to get it off before I just split the crank and pull the pistons out backwards. many thanks michael