Replacing a bent Z-plate

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Mar 7, 2005
My right-hand Z-plate is bent and needs replacing. The Z-plate is bent in towards the swingarm and the previous owner appears to have bent the exhaust bracket back to compensate. As a result the right-hand muffer is sitting at the wrong angle and the header works its way loose over time. There is a lot of weight in the exhaust supported in only 2 places.

I have never replaced a Z-plate and the manual has no details. Any tips before I diss-assemble?
Wow! It must have been a pretty good impact to bend that plate! You might want to check the frame closely as that kind of impact could easily bend the tubes.

Removal of the Z-plate is easy. Remove the muffler mount plates, unplug the zener diode. Remove the ground strap attached to the lower footpeg mount. Removing the footpeg mount is optional. The trickiest part might be removing the nut from the isolastic stud. This is a nyloc and sometimes the stud will turn and unscrew itself from the LEFT nut. If this happens you can either lock two thin nuts on the left to hold the stud while removing the right, or support the engine cradle and tap the stud out with an aluminum drift until you can get a pair of vise grips on the unthreaded section of the stud. Once the right nut is removed, there are two bolts with nuts and the plate will come off. Be careful not to lose the spacers.

Many years ago I purchased a rough commando for parts. Removed a z plate from it that had been cut out of solid steel, same thickness, no holes in it to lighten it. Maybe you'd like that one, it won't bend easily.

Flog Your Flastic
64 Featherlastic 850
Thanks Ron...

I am waiting for a new Z-plate to arrive.

Norflog - thanks for the offer on the steel plate but I'll pass on that one.
Yes, I figure you would decline. Who would want to use a 12 pound part when an 8 oz one is quite adequate.

Some day we ought to start a museum of all the bizarre stuff that we pull off of some of the old Nortons we've bought.

Cleaning Alloy

Got my Z plate but it must have been lying in a dusty warehouse for 30 years.

I need to clean it and polish it before installing. Any suggestions on the best way to lightly polish alloy like this?
TT (tourist trophy?),

I’m currently polishing the aluminum alloy crank arms on my Bianchi bicycle and found the following technique works great for a high polish; you may be able to modify it for a “light” polish.

Sand all visible surfaces with 320-grit wet/dry sandpaper using plenty of water. I sand in the bottom of the kitchen sink and continuously run water over the part.

Follow-up with 500-grit sand paper, using plenty of water.

Dry the part and rub down with 0000 steel wool.

Using a soft clean cloth, apply any good aluminum polish; don’t skimp on this step.

Rub off the polish with a clean cloth.

Enjoy the shine on your Z plates!

For a light polish just skip to the 0000 steel wool with the polish. Use small pieces with a small amout of polish. Buff with an old towel or tee shirt. This will take away the tarnish, works on old chrome as well. norbsa

Thanks guys...

TT - just my initials..

I will post before and after photos when assembled.
The Next installment

Well it seems that the Z plate was not bent but installed with the incorrect number of spacers.

I think the PO had an issue with the kick start lever fouling the muffler. By removing some of the washers from the 2 main bolts it angled the Z-plate towards the swingarm - trying to tuck the muffler into the frame away from the kick-start lever.

Now it is installed as per the manual and it fouls the muffler - just.

As I have a spare kick-start lever I might see if I can get it bend slightly to clear the muffler. If that fails I will invest in a Mk3 kick lever...
Although I need to start saving for that - last quote was AUD$170.

Have any forum members with MkIIa 850s installed a Mk3 kickstart lever?

It's not a MkIIA, but my built from pieces '73 Interstate has a pair of Tom Epperson stainless peashooters. These taper continuously from the inlet rather than having a bit of straight tubing at the inlet. This caused the early style kicker to foul. The MkIII kicker gave just the right clearance. Old Britts has a comparison of the two with pictures on their site. The MkIII kicker gives about 3/4 inch more clearance.
Thanks Ron.

I want to sort out the clearance issue before I go to new pipes. The left-hand peashooter has several dents - from the lickstarter and peoples boots.

Are the stainless steel peashooters worth it? Do you have stainless headers as well?

I have found that the reason the early kickstart lever hits is due to the fact that the "mounting bracket" on some after market mufflers is "wider". This sits the muffler out further & causes the earlier kickstart to hit.

Has anyone else noticed that ?

On my 850, I have ground the mount point & discarded the standard "rubber mounts' for some thinner ones. I have used the thinner ones with shorter bolts etc.

This has brought the muffler almost hard against one of the two bolts that mount the muffler bracket to the z-plate. It now has enough clearance.
All the Nortons I've ever owned have been the S type or the MK III. So, I 've never had to deal with the kicker scraping the silencer.

However, I've seen some really thick rubber spacers that would cause interference between the kicker and the silencer on some Nortons. I accidently purchased some of these "fat" spacers but did not install them for fear they might cause a problem. These spacers my indeed be the problem.

Thanks for the advice.

I am carefully measuring all the new & old parts - new rubber spacers and new mounting brackets. The new rubber spacers are 2mm wider than the old... while the new SS mounting brackets are 1mm narrower than the old steel ones.

I will assemble the right hand side exhaust later this week using old rubber spacers and new SS mounting brackets. Lets see if a 4mm reduction in width helps with the kickstarter.

I never thought that the replacement parts would have such variance in size.

I will be able to do it in my sleep soon ...
My pipe used to often get in the way of the kickstart, took all the chrome off the pipe too.
Noticed that when the exhaust nut was tightened, it kind of pulls the pipe with it and in exactly the correct direction to make the pipe, back by the kickstart, get too far out and cause problems. Every time I had the problem, a good kick on the pipe at the point of contact would turn the pipe a bit back in, towards the bike frame and get it out of the way of the kickstart.
I use those thick rubbers too, but I doubt a couple mm here and there will make a big difference in whether the lever scrapes the pipe or not. Retighten the exhaust nut, keeping in mind the situation, and it should be fine...unless mine is just so old and worn thin from the kickstart lever, or dented by my heel...that could be too!!! Best of wishes from Germany!
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