Help with Zenith 68 Carb -Throttle Shaft Seal

Hello All.

Looking for some help on putting a Zenith 68 back together. It came off of a Wisconsin AGND that is on a lawnmower of mine, but its pretty similar to some tractor carbs, so I was hoping someone has been here before me.

Specifically, Im having trouble with the throttle shaft seal retainers. I got the old ones out, and the seals were shot. My new kit has new rubber lip seals (and some neoprene donuts for packing, but I think they are for the choke shaft....) and a domed washer that looks like its supposed to be the shaft seal retainer.

The instructions say to stake the retainer in place. Im not sure how to do that, since the domed washer that is the retainer doesnt seem to want to even fit in the recess in the throttle body. I would understand if it fit inside a bigger opening and you had to smack it flat to get it to stay, but I just am lost as to the best way to get this done.

Any tips on how to get the retainer to stay in? My lawn is starting to get high......

Anyone? I just dont want to screw things up too badly, but I need my mower workin' tomorrow or soon I wont be able to see the cars...

So, sounds like the seal retainers that came in
the kit are too big?

Looks like your choices are:

Reuse the old ones.

Find something to substitute, like flat washers.

Or turn down the new ones. You can put a short piece
of all thread in a drill, double nut the retainers
onto the all thread, spin them with the drill
while holding a file to them.

Whatever you use, you want them to just fit in the
recess around the throttle shaft. "Staking" them
in means you get them in place, fully seated in
the recess, then using a pointed punch, punch
about 4 places around the edge of the raised area
to keep the retainer in. Just be sure everything
is right before staking them in. Once they're in,
they will be very difficult to remove!

(quoted from post at 22:31:41 05/25/14) So, sounds like the seal retainers that came in
the kit are too big?

Looks like your choices are:

Reuse the old ones.

Find something to substitute, like flat washers.

Or turn down the new ones. You can put a short piece
of all thread in a drill, double nut the retainers
onto the all thread, spin them with the drill
while holding a file to them.

Whatever you use, you want them to just fit in the
recess around the throttle shaft. "Staking" them
in means you get them in place, fully seated in
the recess, then using a pointed punch, punch
about 4 places around the edge of the raised area
to keep the retainer in. Just be sure everything
is right before staking them in. Once they're in,
they will be very difficult to remove!

Click to expand...

Thanks Steve!

I am never quite sure with certain parts in rebuild kits. I didnt know if it was just me, or the bits that came with it. The old retainers were pretty well shot, but Ill see what I can do to compare to size.

Really appreciate your detailed description of things, its very helpful!

(quoted from post at 07:07:11 05/26/14)

(quoted from post at 22:31:41 05/25/14) So, sounds like the seal retainers that came in
the kit are too big?

Looks like your choices are:

Reuse the old ones.

Find something to substitute, like flat washers.

Or turn down the new ones. You can put a short piece
of all thread in a drill, double nut the retainers
onto the all thread, spin them with the drill
while holding a file to them.

Whatever you use, you want them to just fit in the
recess around the throttle shaft. "Staking" them
in means you get them in place, fully seated in
the recess, then using a pointed punch, punch
about 4 places around the edge of the raised area
to keep the retainer in. Just be sure everything
is right before staking them in. Once they're in,
they will be very difficult to remove!

Click to expand...

Thanks Steve!

I am never quite sure with certain parts in rebuild kits. I didnt know if it was just me, or the bits that came with it. The old retainers were pretty well shot, but Ill see what I can do to compare to size.

Really appreciate your detailed description of things, its very helpful!

Click to expand...

Rebuild kits leave a lot to be desired sometimes. Quite often, there are parts included in the kit that a person will not use because those are for a slightly different model, and just as often, the parts that ARE for your model are not quite correct and will not fit. I have had to re-use original parts many times, and when the original is NOT re-useable, you improvise.

Agree entirely Rusty.

I usually dont have to get into re-bushing or throttle shaft seals, so this is a new adventure for me on all of the various carbs that I have gone through. So I wasnt sure if the issue was me or the parts, or a little of both... (Pretty sure its a little of both....)