1971 Norton Commando Rebuild Thread

Jerry Doe

Admin
Joined
May 21, 2003
Messages
1,534
Country flag
I have decided to start a thread for my 1971 rebuild. Its been many years since I worked on a 750, so I might have some questions. I have been reading the forum and there is so much to know. I promise I will search first. It's great. I am not sure how I am going to build this bike yet. I do know that there are some things I must do right at the beginning though like getting the cases to Matt for the breather mod. I have been reading about the side stands and learned that the 71 stands are bad news because they are pinned and can fall to bits. I looked at mine it it is not pinned and not like a 72 onward type. Please have a look at these pics of my stand and let me know if I should grind it out and put a later one in. The one I have looks ok to me. Perhaps I will "through bolt" it.




When I restore I always forget to take good before pics. This time I took a few, see below.







There are a few parts missing as you can see, but in general its not that bad for $800. I have not tried to turn the motor yet (still soaking). This is going to be a fun project. I expect it will take a while, which is cool as I ride my MK3 all the time.

Per the other registration thread that I started, I was able to get the bike completely registered with a Bill of Sale and an Inspection. So time to take it apart- cheers
 

Attachments

Joined
Aug 18, 2013
Messages
132
Country flag
The heavy tab in front of the new kick stand and on the inside of the frame is the original 71 kick stand mount. the stud to go through the kick stand is broken off. the common problem.

Not sure about your current kick stand, it looks like it is welded to the frame tube and it could cause a stress crack over time.

The new kick stand mount from Old Britts mounts to the side frame and the cross tube for better strength. the mount is cheap, not so much for the new kick stand and spring.

Dennis
 
Joined
May 11, 2010
Messages
2,397
Country flag
Have you given any thought to having the frame and swinging arm checked out on a frame table?
Now is the time before you get it cleaned and coated.
 
Joined
Sep 21, 2009
Messages
1,609
Let me know when you need a hand. Josh (transcon here) just gave me a brand new clutch cable to give you for this project, he also has a unused seat, one of those cool single cafe type from England he will sell at a great price if you don't go stock. Glenn T.S.
 

Jerry Doe

Admin
Joined
May 21, 2003
Messages
1,534
Country flag
Started taking it to bits. Very happy with the condition. Looks like someone took care of it once. One interesting thing was the last clutch spacer. Someone had drilled and pinned it. I have never heard of this before, see the pic below:


Here are some other pics during dismantle:
 

Attachments

DogT

VIP MEMBER
Joined
Jan 20, 2009
Messages
7,209
Country flag
Yeah, that's the way my clutch plate looks.

Dave
69S
 

Jerry Doe

Admin
Joined
May 21, 2003
Messages
1,534
Country flag
Thanks for letting me know. I had no idea about that. I took the head off this morning and one of the pistons is in the wrong way around...
 
Joined
Jul 11, 2010
Messages
3,574
Country flag
Jerry Doe said:
Thanks for letting me know. I had no idea about that. I took the head off this morning and one of the pistons is in the wrong way around...

Thats proberly why the bike sat for awhile, one side of the motor wanted to go forward and the otherside wanted to go backwards :roll: anyways its a good cheap project bike, all the best with it and have fun.

Ashley
 
Joined
Dec 21, 2008
Messages
158
Country flag




Jerry,

When you get around to disassembling the front and rear brake, remember that the brake drums may contain dust with asbestos present. I'd open them up outside the shop, take a deep breath, and blow them out with compressed air -- on a windy day, of course.

Clutch plates probably have asbestos in them, too. At least the original ones.

That might be an interesting thread to start: "Potential Environmental Hazards Present in Norton Motorcycles."



Also, I really enjoyed the video you posted on youtube of you out and about on your MK III. Far too short, but well done, in particular the portions with the camera mounted down low on the left side of the bike, as the sound was much better with the camera mounted in that position. Please consider making more videos, that are greater in length.



 
Joined
May 11, 2010
Messages
2,397
Country flag
Id carefully dunk the hubs in warm soapy water and use a parts cleaning brush after they are
submerged to get the asbestos dust out.
You are going to immediately dry them and toss the bearings anyway.
 

Jerry Doe

Admin
Joined
May 21, 2003
Messages
1,534
Country flag
A quick update.

After stripping down the bike I have found a few minor issues:

1) Upon examining the frame it had a different side stand welded on. I am sure that stand would be ok (see pics above). In my mind though the only choice would be to remove that section of the frame and have a new section welded in with the later style lug. The original frame had 2 small holes drilled in the loop too. Well that's what I was going to do and then I found a 72 frame on eBay and bought it. I am going to use that frame now as it has the later lug. The loop looks a bit bent on the '72 frame so still trying to work out what to do about that if anything.

2) The front end is completely shagged out. I am selling the TLS hub and R/H leg. I have purchased a R/H disc fork leg from Mike and for sure will be using a disc front end. Not sure which way to go with that. I don't have the same budget for this rebuild as my MK3 rebuild, so we will see. I got to say the front brake from cNw on my MK3 is brilliant. I might do that again. I know it won't be stock.

3) The crank cases were covered in crap. I cleaned them up and found 2 cracks around the bolt holes (see pics below). I am sending the cases to Matt at cNw for the breather modification, then tumble and he is going to repair these cracks for me. I am also sending the gearbox shell for the tumble treatment, as well as inner case. I am sending my oil tank as well for the modification that they do. This will be the 3rd one I have had done. Its a no-brainer to me. If things cost more during these rebuilds, it just takes longer.

First Issue


Second crack


Mrs is happy I did not use the dishwasher this time
 

Attachments

Joined
Jun 1, 2003
Messages
2,013
Country flag
here is MY dishwasher in the far right. the mrs has been told it is off limits. :mrgreen:



Jerry Doe said:
Mrs is happy I did not use the dishwasher this time
 

Jerry Doe

Admin
Joined
May 21, 2003
Messages
1,534
Country flag
Nice. Looks like you are set up for some heavy equipment too.

I forgot to mention one thing during the dismantling. Removing the timing side crank woodruff key was a nightmare. After lots of tapping and heating i used the dremel to grind a hole in one end and with heat got it out. Probably spent 4 hours on that. I thought i was damaging the shaft, but after i got it out all looks good, thew..
 
Joined
Jun 1, 2003
Messages
2,013
Country flag
actually I do a some automatic transmission work on the side. it was a 35 year profession with my own shop and now semi retired. I do some norton repair and all the way up to some heavy equipment repair for a friend. the side benefit is I get use of excavators and bulldozers on my property at no cost and I started digging the basement for our new house this week.

Jerry Doe said:
Nice. Looks like you are set up for some heavy equipment too.
 

grandpaul

VIP MEMBER
Joined
Jan 15, 2008
Messages
11,117
Country flag
Jerry, it's great that you are starting this thread. You of all people have the best advantages of the forum!

As soon as I started looking at your "before" photos, my mind began to see the shiny paint & chrome. It's amazing.
 

Jerry Doe

Admin
Joined
May 21, 2003
Messages
1,534
Country flag
It's gradually coming together. It's happening in phases. I am in no rush as I have my MK3, but this is getting exciting and expensive. My Frame is away being fixed (more about that later). Another frame was butchered to fix the one I am using. I should have it back next week.

I am going to use webcam from Jim (TNX Jim) and he is radiusing the lifters. I have a combat head, but will go with a standard and that's going to get sorted later after I win the lotto.

I had some damage at 3 bolt holes in the casings and I sent them to Matt to tig weld. While he had the cases he did the breather mod and added bearings for me and gave them the "cNw" treatment. Same kind of treatment on gearbox. I am very happy with the results- Just took some pics:






 

Jerry Doe

Admin
Joined
May 21, 2003
Messages
1,534
Country flag
A quick update on my 71 rebuild. It's been a long time as so much needed doing. I decided it is not going to be anything like original.

I had to butcher 2 frames to fix one good. The original frame had conduit welded in the back of the loop, so cut that out and welded a loop in from another frame. I thought that the gearbox was not too bad when I first looked, but it was pretty much trashed except for the shell. Most internals are new now including all new bushes etc.

The crank is away being balanced and as soon as that is back the motor is ready to go together. I have the re-bore etc. Jim has the head and is fixing that up. I

I've been focusing on the front end. Got some Forks by Frank tubes and doing the conversion for better damping. I have a disc fork leg and a decent wheel. I am sticking with 19 inch rims on this bike. Not sure about the front brake yet.

I have all of my chroming back as well as powder coating. So I am finally ready to make it look like a bike. Exciting time :D

A couple of starting pics:
Gearbox ready to go in:


I think I will build it here:
 
Top