1973 Mk1 Rebuild, back from the grave!

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I have been very busy with work, so I don't have huge updates, but I have spent some time working on the Norton. I have the frame completely prepared according to the Old Britt's guide. I am planning on dropping off the frame, swingarm, and misc. parts off tomorrow on my lunch break.

While waiting on the cylinders and frame to be powder coated, I thought I would dive into the gearbox to replace the infamous layshaft bearing, just in case.

I could not believe how hard it was to take off those straight style screws on the cover! I broke off two of my impact bits (high quality US made impact driver), and three of the screws had to be extracted.


The first screw came out with an ez-out style extractor, so that was encouraging!

The other two were not budging, and I was afraid I would crack the cover by pounding in the extractor too tight. I ended up drilling out the heads.

I ran out of time before I could finish the job today, but I didn't think it looked too bad inside. It had a little sludge buildup, but nothing too terrible. I plan on completely dissembling it, cleaning everything, replacing the seals and gaskets, and then reassembling.



Upon reassembly, I am definitely going to use some good stainless torx or allen capscrews.

Not really project related entirely, but I went to a motorcycle show in my small town (Grand Forks, ND) and was happy to see a CNW bike there! I was able to chat up the owner for about 45 minutes, couldn't have been nicer and more gracious to my questions. I wish I had asked for his phone number so we could go for a ride sometime.

Funny enough, i had actually saved a picture of his exact motorcycle off the CNW webpage, and was using it for inspiration on my phone, before I had met him!

 

grandpaul

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If you take the proper impact tip, set it in the fastener, and smack it smartly with a hammer BEFORE you engage it with the impact tool, the fastener will typically release better/sooner.
 
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If you take the proper impact tip, set it in the fastener, and smack it smartly with a hammer BEFORE you engage it with the impact tool, the fastener will typically release better/sooner.
Good advice. I probably should have stopped and asked before I went through that much aggravation. I went straight for the impact.
 
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Gearbox is all finished up!

Got started on rebuilding the bottom end

Things were looking surprisingly good inside considering how long it sat

Journals looked good.

Glad I am swapping out the bearings. I tested plastigage for fun on the old bearings and they were still perfect in size, but look to have a little corrosion.
 
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Doubt you need the crank balanced since you are going back with mostly stock bits. Mine have never need it.
 
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Should I mention crankshaft balancing.
hoping it is not needed. I am keeping stock rods and just replacing the pistons and rings / bearings. I don't plan on flogging it too hard, I have my vmax and ducati for those shenanigans!
 
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finished verifying gaping of the rings. Is it my imagination, or are the rings the same for the top two? They measured up identical, same with the chamfer.

bottom end mostly put back together. I need to polish the outer cover and replace the seals on that. Still need to install the points, but I think I will remove and replace with some kind of EDI before the project is done.
 
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IMHO the Pazon Surefire ignition system gives the most bang for the buck. I have five bikes with it fitted. You can use your stock 6V coils with it assuming they are okay.
 
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Might be my eyes but is that oil pump seal convex outward ?
Yes, did I put it in backwards? I just put it in the pump so I wouldn't lose the piece, guess I should have double checked the book first. I still need to replace the seals in the outer cover, but I was going to polish it first.
 

L.A.B.

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"Convex outward" is correct, however, it appears to be an 850 Mk3 timing cover oil pump seal.

850 Mk3 timing cover pump seal:
https://andover-norton.co.uk/en/shop-details/16729/oil-pump-seal-mk3

Pre-Mk3 pump seal:
https://andover-norton.co.uk/en/shop-details/17086/oil-pump-seal-d12-133-nmt272-

Wow you guys are a wealth of knowledge! Thank you! It came in a seal kit for commando 850. The kit was a generic kit that has everything needed for Mk1-Mk3 I think, so I will double check if I have the correct one. The old seal was smashed to smithereens so it was hard to tell the orientation or original shape.
 
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I haven't had much progress made due to work and school obligations, but I did get the frame and swingarm back from the powder coater!

It didn't turn out perfect, but I am satisfied with it. There are some imperfections that I could not see in the frame but were probably obvious after the shop had sandblasted everything. I wish he had given me a chance to smooth it out, but he just powder coated over the areas where there was imperfections instead. Luckily they are covered by the seat and the tank for the most part.

 
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Coating looks good. Every time I look at one of these frames the first thing that comes to mind is 'piece work' because of the, what I consider, shoddy fit ups at the tubing connections. I know cost was foremost...but for Christ sake there could have been such a thing as pride in work.
Again your man did a nice job.
 
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I feel really bad that I let this thread die down. I have been so busy lately I when I had the spare time I spent it on the bike instead of updating the forum! I'll try to do a better job keeping up going forward, especially since I will start needing more help I am sure when getting closer to the finish line.

As for updates, I'll try to bring the bike build threat up to date here.

I sent off the head to Jim Comstock last April, so I am hoping to get it back soon. At the moment this is one of the big items left to deal with.

The fork tubes were in awful shape. Thankfully, the inside still contained oil and had no pitting in the lowers. I was able to purchase new seals / gaskets / tubes and rebuild them.


My old wheels were extremely rusted. I was able to find this for sale on the Access forum from a member, so that was a big win. I still need to replace the tire, as I am sure it is hard as wood even though it looks good visually.
 
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I was able to find a local engraver to etch the new VIN plate for me. I know its not original but it works for my purposes.

My front brake was in awful shape as well. Somehow, there was no corrosion inside, and new pistons and seals were enough to bring the caliper back up to snuff.

I don't have a good picture handy, but I ended up using one of Don Pender's 13mm master cylinder units. Seems like a really nice kit and it allows Norton original switchgear to be used.

I had to divert some garage time over to the Ducati before the desmo valves made me regret it. Somehow I think the Norton will be easier to adjust valves on.
 
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