03-01-2023, 07:25 PM
Thanks Ian, Chris and Jim for your replies.
I will be following up on checking the main centre bearing and the crank.
Jim, I had fitted new springs to the distributor weights and checked that they move freely. When I twist the spindle I get about 3 degrees rotation before the weights start to move out. This appears to be taking up the ovality of the pivot pin holes. I then get a further 5 degrees of twist bringing the weights to full out position. Hence I suspect that at idle the ovality is already taken up and I will only have 5 degrees of advance available for higher revs.
I have set the timing by road test to give good uphill performance at 30 mph. Advancing and regarding the timing from this setting doesn't change the noise coming in above 40 mph, but does affect the uphill performance. That's a pity because I will have to look at more difficult remedies than ignition timing.
I will be following up on checking the main centre bearing and the crank.
Jim, I had fitted new springs to the distributor weights and checked that they move freely. When I twist the spindle I get about 3 degrees rotation before the weights start to move out. This appears to be taking up the ovality of the pivot pin holes. I then get a further 5 degrees of twist bringing the weights to full out position. Hence I suspect that at idle the ovality is already taken up and I will only have 5 degrees of advance available for higher revs.
I have set the timing by road test to give good uphill performance at 30 mph. Advancing and regarding the timing from this setting doesn't change the noise coming in above 40 mph, but does affect the uphill performance. That's a pity because I will have to look at more difficult remedies than ignition timing.