Try our new info resource - "Aladdin's Cave" (Main menu)Just added a separate link to Ash's Dropbox thread (shortcut)
On another note, removing the barrels. How about this, get a thick piece of wood. Cut it so that it fits where the crank would be but is pressing against the liners of the barrels. The wood would need to be thick enough that the lower casing won't quite fit, then bolt the casings together, the pressure from the bolts should pop the barrels off, you only need it to break the seal and they'll come off anyway. OR use the same piece of wood as a drift to protect the liner and hit it with a big hammer. Maybe cut a circle of wood just bigger than the liner so as to spread the blow around it.
I would also bin those crank cases and seek a replacement. If the bearing surfaces are damaged, then all bearing housing will be beyond spec, this will include bearing and oil seal housings.
Hi, I have a 1971 CB750 Honda four cylinder classic bike.I bought the bike already restored, but with damaged main bearings. I have changed the crank for another, known to be in very good condition, measured the journals with a micrometer and fitted the correct shells. When I tourque up the crankcases, the crank locks up, just as the final torque setting is reached. I believe that the problem is that previous media blasting of the cases has removed a few thou of alloy from the crankcase centre joint, meaning that when the cases are tightened up the crank journals are slightly out of round, nipping up the required oil clearance. I have the Honda spec measurements for the bearing shell housings we are talking about a range between 39.000 and 39.008 mm I.D. for the shells I have. If I brought the cases to you, (I am in Stalybridge) could you measure the crank journals' internal diameter for this, and if possible line bore the journals back to spec?What sort of cost are we looking at?The alternative is to use another set of cases, but I would like to save the originals if I can.Thanks, Dave
Yes Chris, I'd like to get the mating surfaces lightly skimmed, but then again every thou makes the problem worse.