March 2021
After the BSA Rally in February Allan's lovely Rocket 3 came to stay briefly as I needed to remove it's copper rocker box gaskets and replace them with aluminium items. There had been a batch of copper gaskets whose holes were not correctly placed, so some interference took place as the bolts passed through, resulting in deformation of the gaskets and annoying oil leaks.
You can see here, with aluminium overlaid on copper gaskets, the top holes are aligned, and the lower holes are well out of position. The lower right hole was the worst offender, as the edge of the hole was badly deformed against the threads of the head bolt, preventing an effective oil seal. The aluminium gasket holes are spot-on.
Work began immediately so the various trims on the tank and around the oil cooler are absent here. I would assume that the job was already complete seeing that the tank is back on for test running.
Some time was spent gauging the correct amount of extra packing required to give adequate compression of the pushrod tube seals, as the aluminium gaskets were thicker.
I test ride after such work in order to thoroughly warm the engine up, so that the head bolts can be retightened once it has cooled, and usually I find that nothing moves any further when solid gaskets are in use for the head and the rocker boxes. That means I do not need to revisit the valve clearances. I also leave the head braces off until all work is completed.
While I was pleased to note that no oil leaks were apparent from the rocker box area, there was oil leaking from underneath the bike, and of late the oil consumption had been on the increase.
It turned out to be from the oil filter cap, which fortunately had just not been sufficiently tightened, rather than had begun to strip it's threads.
As it happened I had a brace of BSA's to look at as follow-ons from the rally. Neither because of breakdowns, more that contact had been made with the owners so the work was given some priority.
Back to back test rides are no bad thing.!
As the Rocket 3 seemed to be behaving itself, all the trim was refitted and it was ready to leave.
Subsequently Allan came to collect it, and pleasingly it fired up in it's normal happy fashion.
So off they went. Next stop Blenheim. Now that really is a thorough test ride.
He reported later that all had gone well, and most of the traffic was going the other way.
Perfect.