Hitchcocks Forum

I'm restoring a 1995 500. I disassembled the distributor to clean it out and re-grease. I can't get the cb/timing pinion gear (from the timing cover side) fixed back on the taper of the cb shaft. All the direction I've been able to find says just "give it a smart rap with a hammer". I don't want to hit the gear with a hammer, nor the points plate or cam/governor assembly. There is also about 1/4 inch play/movement of the shaft inside the distributor body, which would make striking ineffective. I can't use the pinion nut to force them together, since the shaft turns. Any suggestions?
Thanks.

The gear pinion which is visually different from the idle pinions should just push onto the taper at the end of the distributor shaft and is held tight by its own nut. The nut can be tightened fully with engine in gear and back brake on to hold the gear train steady. The end play can be reduced by moving the pressed in bushes further apart.


If funds permit the later distributor housing with roller bearing is far superior and reduces sideways play to an almost imperceptible level, any sideways play affects when the points open and the ignition timing.

No, I wouldn't hit a gear with a hammer either but if you find a socket that fits over the shaft and bears against the gear, a sharp tap should seat it on the taper. As Ric says, in gear brake on will stop the shaft rotating. That does seem a lot of lateral play, is there much axial play?

Thanks for your suggestions. Let me add some more info. The engine is off the frame to allow me to clean up and restore other components, so putting it in gear or applying the brake is not an option right now.

Anyway, pinning the gears would not allow me to tighten the nut, since the nut screws onto the shaft and the shaft spins in the distributor body. I would have to somehow hold the shaft stationary until the nut tightned up the taper. Hard to do while it is inside the distributor body.

The bike has only 1923 miles on it (was told it was used only for promotional events) but was severely neglected. The shaft moves slightly in and out of the distributor body. There is no sideways movement of the shaft when fully seated in the distributor, so I'm thinking the bushings are OK for a while. I'm sure the movement will go away when I tighten the nut (there was no movement before I disassembled), but I need the gear to be tight on its taper so the distributor shaft doesn't turn while I'm tightening.

I was able to get the timing advance mechanism on its taper with a hammer rap, but that was out of the distributor body and on my bench.

If I were to try the socket method, I would have to somehow brace the points side to take up the excess movement while I rapped the gear side. I'm thinking of using a large C-clamp and trying to squeeze the taper on its seat. I guess I could also wait until I had the engine and tranny back on the frame to do this.

Kurt

Kurt, you need an assistant with something heavy braced against the other end of the shaft. The G cramp could work I guess.

Kurt - I had no problems replacing this pinion on my 1996 500 when I rebuilt it first time (Oh yes, you can look forward to more times). But it wouldn't go on at all if the gear was the wrong way round. Are you sure your's is correct? Alternatively get a big C-clamp and force it - can't do much wrong, can it!

BTW I also found the original distributor had a bit of play and assumed it created a timing problem. So I replaced it with a newer distributor with the proper bearings as ric suggests. Didn't make much difference though and there's still a bit of play. I later found the timing issue was because of non-smooth slots in the A/R weights - judicious filing and polishing resolved that issue.

BTW You shouldn't need to hit the A/R mechanism to get it onto the taper. Just a finger push shoudl be enough to hold it in place before bolting it.

Be very careful about hitting or forcing anything on those 90's Bullets. I once had to remove a stuck threaded shaft (9/16" BSW) on my Bullet. So I refitted the nut to protect the threads and tapped it twice with a 1lb hammer. The shaft loosened easily. But when I removed the nut, about one third of the threads came off with it!
Cheers, ChrisD

Hello Kurt,
Wen I have to work on tappered assemblies, I allways take some time, at least to look carefully at the "male" and "female" cones, and if necessary, make a bit of lapping, or with fine grinding paste for the biggest, or with polishing paste for the smallers (BSA A10 magneto experience...). Once you are sure that the two parts settle perfectly (matt grey on the whole surfaces), you can give a small blow centrally on the pinion, I use a sprocket for that. To avoid the pinion to move, I block a small towell between the 2 idler gears, to prevent them to move, so your pinion won't do too. Once all that tightened, have a look at the ignition settings. Hope it will help you. Claude

Thanks for all the suggestions. I did get it fixed on. I removed the points and timing advance plates, enlisted the help of an assistant who held a wrench handle across the gear and used a c-clamp with a socket on the points side to snug the shaft into the gear. I'm waiting to torque the bolt until I have the engine back in the frame and am ready to address the timing.

Kurt