All the pieces are ready, I'll have the welder form perfect saddles on the two uprights and tack everything together, then mock it up on the bike and test range of motion. I'll also be marking the notch for the chain, and have them cut it and weld in the angle iron brace. While I can "stick weld" acceptably, I want the finish on this piece to be as near perfect as possible. Next stop will be the machinist to have him cut the two pivot lugs to fit a set of standard swingarm bushings for the rising rate linkage pivot rod (a bit of overkill).

Disassembly started yesterday; start with removing the exhaust to set it on the lift-


Tank, seat & sidecovers off-


Rear fender, meters, handlebars & controls off-

Forks off-


Carbs off-


Flip side-

Rear wheel off-


Left footpeg & z-plate, rear sprocket assembly & chain off-


Primary cover off, so far no suprises whatsoever-

Primary system removed WITHOUT PULLERS!


Right side footpeg & rear brakes removed-


Not sure how many miles this doll's shoe has on it, but it fell out from behind the Z-plate...

Got a call from the welding shop just before lunch...


Time for a working mock-up to test range of motion.

I'm going to shift gears a bit and move progress over to the "test mule" parts bike that will get this prototype monoshock setup and a '74 850 engine.

Meanwhile, the client's stuff will get thoroughly cleaned and the top end job will commence sometime in the next week or so, once I get the monoshock completely welded up and have a rolling test bike.

Conveniently, I have these two, as well as the other client's N15 hybrid that will all enjoy discounted pricing on powdercoat, paint, chrome, polishing, parts shipping, etc. It's always nice to take advantage of volume discounts, this time all three are Nortons!

One thing for sure, the head was WELL TORQUED! All of the fasteners gave a healthy “pop” when they broke loose, then screwed out cleanly by finger, very nice.

Typical carbon buildup, maybe a bit on the heavy side. Pushrods in decent shape; one has a “polished” area, maybe I’ll re-work the pushrod tunnel a tad to give a touch more clearance there -



Copper head gasket is in decent shape; pistons have a good bit of buildup –



First point on the “disappointment” list – connecting rods are nicked from top to bottom, all the way around; I think something was adrift in the crankcase, rattling around for a good little while –

Second disappointment was the cam – the lobes were all pitted –

Cylinders were in decent shape; they’ll go first oversize with no worries –



Pistons are .std, but worn out & beat up –





Whatever was floating around in there did some damage. Cases will have to be split no matter what; cam has to go at a minimum.

Next disappointment - the dreaded "D" spec connecting rods. No big deal, they were beat all to heck anyway.



Last disappointment (for today) - cam followers were trashed by the pitted cams –

Thanks for the pics GP,
Another "quality" cam,
And rods,
Interested to see what's floating around in the dark, oily innards?

Stay tuned to this thread...

Great pics, a great post and yet another excellent thread GP! I know it's not so convenient stopping to take photos when you're right into things. Do you have a computer in your shop?

Oh man, things sure took a turn for the worse. Just goes to show, we don't always know what we think we know about our engines. I had to go back to page 1 and here's a quote - "3. It will not be a total engine overhaul, just a beefed up top end job (bottom end is in great shape)"

It's a good thing you dug into it when you did. I wonder what shape the bearings are in.

Thanks a lot GP your extra efforts are much appreciated!

Righty-O, the bottom end was not in the plan. it is now! Since the top end was coming off, a cursory visual inspection of the bottom end was anticipated anyway, not like I was going to stuff it with rags and disregard it altogether.

My garage/shop/office is all one building, but it's like a maze. My camera is rather shopworn and greasy, but does the job under stress.

...just doing what I love to do...