Jeez time flies.
Figured out the transfer of rpm-related vibration to the rear axle was through poor exhaust alignment. The pop-up over the axle was hitting the trunnion nut all the time. Pounded it out of the way and all better.
Every 20 years I make it a point to look at my carbs. Car came to me in 1997 with a non-orig 1600 with rod knock, apparently original 40 DCOE 24 carbs and manifold. I installed an APE 1750 about a year later, rejetted the carbs to 1750 specs, all good. Over the past month it's been a bit stumbly, so I did the recommended thing, checked all the ignition first. Changed plugs, wires, cap, rotor, etc, no better. At big throttle openings is OK, stumbles just off idle.
The plugs for 3 and 4 were just utterly black. 2 was pretty dark, only 1 was OK. Poked around, pulled the tops off the carbs and three of the four starter circuit c-clips were broken and the little "volcano" caps were wearing into the carb tops. Hmm. So pulled the carbs off today. Three of the four starter plungers were stuck up, only one was seating in the bore. So those three were allowing extra gas to get drawn in all the time I think. I have some extra 40 DCOE 28 Jr carbs, same pieces, so will cannibalize to make these right. I've seen the broken c-clips before, but only on a shelf carb, not on a running one. Must make it a point to check the carbs each decade.
Also note the cool green Cavis plug wires. While I was at it, checked a few valve clearances and timing, haven't done so in maybe 6-7 years. All good. What great engines.
Last edited by Andrew; 08-07-2018 at 03:26 PM.