Following my progress report of nine months ago, by which time I’d restored the rolling chassis of my 1937 350cc Cotton-JAP, I lifted the engine on to the bench and the first thing I noticed was a shake in the drive-side main bearing.
As I explained in part one, there are two rows of rollers running directly on to the main shaft. My mate Arthur had re-worked this in the 1960s when we first got the bike, and fitted oversized rollers.
Upon inspection, the rollers were slightly down on 7mm, so I thought maybe I could get away with splitting new 7mm rollers. I obtained new rollers, but, of course, these were 7mm long and needed to be a quarter of an inch long.
Read more in July’s edition of OBM
