Hi all,

I have a 1991 XT600E that had its engine professionally rebuilt about 6 months ago, at about 85 000 miles (140 000Km). The work included replacing all the crankshaft bearings, new con rod, re-bore etc. This cured the oil consumption and loss of power but not the excessive amount of vibration that had developed during the last few thousand miles before the rebuild. Unfortunately, that mechanic has now emigrated.

Initially I thought that this would improve when the engine had done some miles but 4000 miles later, no improvement. Then I thought tight spots in the final drive chain were the cause, but replacing this didn’t help either

A friend and local mechanic has had a look and discovered that there is some play at the end of the crankshaft, visible when the circular cover is removed from the left side engine case and a screwdriver levered against the nut on the end of the crank. He is reluctant to investigate further as he believes that at 90 odd thousand miles the crank cases will have suffered a lot of strain where the main bearings locate.

Is he right?

I don’t know yet if the (new) bearing is at fault or if where it locates in the crankcase is damaged. If the case is damaged, is it practical to repair?

Is it worth spending even more money on?

Thanks in advance for your thoughts

Mark