Kickstart seal replacement

73 750- Have x-ring to fix leaking kickstart. Have read threads about pushing o-ring in from outside; but looks like I have to pull bushing out to put x ring or seal in from inside.
Have never opened Norton gearboxes before, would appreciate advice.

Dental pick.

The bushing comes out from the inside of the cover and then you can replace the seal.
Use a little heat and tap the cover on a wood bench and it will fall straight down.

You may be aware that there are services available that can machine the opening and upgrade the seal to the Mk3 design. The key, in any case, is to insure that the k/s shaft has a smooth nick/gouge free surface. Given the way the k/s return spring is installed the k/s shaft is commonly buggered with lengthwise insults which can quickly undo the integrity of any new seal.

The picture you posted indicates to me that the k/s arm has gone through periods of being loose, so do check the splines on both the arm and shaft for damage. Regaining a good, tight fit, when clamped, can be facilitated by Dremeling down 2 or 3 of the splines on each side of the opening on the k/s arm that allows it to clamp or relax.

If this was mid winter I'd have suggested you send the cover out for the Mk3 seal upgrade. Given that the riding season has started I'd suggest a new "O"/"X" ring, watch for leaks and check g/b oil level; next winter consider the seal upgrade.

Best.

I put an X ring in mine recently and just picked out the old one with a jeweler's screwdriver. The new one went in just with fingers.

I have tried various alternative recommended seals but the one Andover /Old Britts sells now works great. Dry. No need for machining.

I've tried the X Ring and it was so so. I got a 90 hard viton O ring that was one size larger in diameter and worked it into place with an oily wooden dowel rod. It tighter than the stock O ring. Its been the best solution so far and its lasting longer than the X ring did. Sometimes the simplest and cheapest solutions are the best.

Got the mk3 modification done a fair spairs in california. Everyrhing else leaked .So far so good.

Thanks for all replies. Think seal is way to go, maybe after I get the other bike going again. X-ring for now. Been riding since Ground Hog Day 6-8 times middle of WI.

We have a fixture plate at the shop that we mount the outside gearbox cover. We then machine two counterbores for lip seals. one for the kick starter shaft, and one for gear selector shaft. Problem is it has to go to a shop for the work, or you have to have a mill in your garage. Best fix we have found, but needs machining

There is a conventional oil seal that will push in as a straight swop for the o ring.. I fitted oneyears ago and it works a treat. Think it was detailed on
an INOA fact sheet copiedyears ago by the NOC in Roadholder

oldmikew said:

There is a conventional oil seal that will push in as a straight swop for the o ring.. I fitted oneyears ago and it works a treat. Think it was detailed on
an INOA fact sheet copiedyears ago by the NOC in Roadholder

Click to expand...

Thanks, have to look it up if x-ring starts leaking.