Hello. I hope some of the wise heads out there can help with an irritating problem with my 1954 A7SS.
It was rebuilt about ten years ago for a museum. After being on display for a few years, it was later bought by the guy who'd done the engine rebuild. I've spoken to him and he said he rode it a bit, before selling it on. The last owner told me he'd probably done no more than 100 miles on it. In between it spent some time sitting in a dealer's showroom.
I've been driving it through the summer. First impressions suggested that it's probably not yet run in, so I've not been thrashing it. It starts very well, and runs sweetly (cruising comfortably at 50 mph on a gentle throttle). Then, after it's done about four miles, it starts to be hesitant. It won't pull cleanly - it's a matter of finding the spot on the throttle where it's OK and staying there. Too much or too little throttle and it hesitates and it won't rev past 50 mph in top. Initially I put it down to the muck that was blocking the banjo filter on the carb - there was tons. But after several sessions of rinsing the tank, and the fitting of fuel filters, I'm sure that's sorted.
I've checked the points, and the auto advance seems to operate freely. I've also dismantled the carb and blown out all the jets - it's an as new Monobloc. I wondered if perhaps it was nipping up?
Any thoughts would be gratefully accepted.