CRACKING UP
I was happy to see Frank’s finished Matchless X in the magazine. I bet it’s great to ride and show to his friends. As the pictures show, I had a sad event after a ride last August. It was a good day, no problems with my AJS, and I put it away for three days. On the third day I found some oil on the floor under the points cover. I thought the shifter seal was leaking. I already had a leaking kickstart seal so I put it on my to-do list. I went to kick the bike over, and it wouldn’t turn over. Uh-oh, this is not good.
I removed the points cover, and out came a lot of oil, and… a crack is visible.
I sent the bike to Kevin Wilson, the restorer on Vancouver Island, and he did the repairs. The oil pump cover was sent out for welding. I supplied a new kickstart seal which he installed and while doing so he found a loose left-hand threaded nut on the clutch linkage in the transmission that was stopping the gears from turning. The engine was not seized. What would cause this cover to crack as it did? Is it a common problem with alternator versions of 16 and 18 models?
The pictures show a problem I first had with the points plate which was too far to one end to get enough advance. The points are on a tapered shaft and it was an easy fix when the oil pump cover was removed.
I am still dealing with a leaking kickstart seal. Kevin put in the new steel bushing with the new style seal but the improved seal, with a metal band around the outside, leaks twice as much as the original O-ring type. I’m going to try the double-lipped type. If that doesn’t fix it, I’ll replace the kickstart axle which must be worn.
That’s a remarkable pic of your cracked casting. I’ve never seen anything like that before. There’s no stress there so there should be no reason for the alloy to fail like that. The repair looks neat, though. Is everything inside the timing chest OK? The boss nearest to the crack is where the crank’s located (I think), but on those engines the bearing’s under almost no lateral loads, so I’ve no idea how that can happen! The kickstart shaft oil seals always fail eventually in my long experience. I just replace them – it’s easy enough and it’s only a short job. Or I just put up with the drip. My Commando doesn’t weep there at all, however, but whether that has a different design of seal I don’t know. 1965 AMC singles are great bikes – carry on enjoying yours! Frank W