1975 Norton - It's Done!
I guess I need to complete the thread - it's done. I managed to fire it up, adjust the timing and carbs and put about 100 miles on it. No smoke, good power, no weird noises - it seems good.
A few minor issues - I had a leak from the primary and the clutch wouldn't disengage fully (making finding neutral impossible). When I pulled it down, I found the infamous circlip behind the clutch basket deformed and out of position. Yes, I did only torque to 40ftlbs, but it still failed. When I replaced that, and the seal - the leak went away.
I also found the neutral light switch was screwed in too far which also screwed up finding neutral. This adjustment seems kinda touchy. I think either my switch is going bad or the bump on the shift plate is worn. I managed to find a workable medium.
All in all, I'm very happy with the bike and hope to get many miles out of it.
UPDATE: Replaced the neutral switch and also opened up the tranny. I gently smoothed out the neutral light "bump" on shift selector plate and spent a lot of time with the switch adjustment. I also shimmed the Hyde shift pedal (it was kinda sloppy on its pivot shaft). Now it finds neutral better, but still not as nicely as my other '75. I suppose there's more "fettling" to do...
Since I mounted the vintage Hyde rear sets AND decided to delete the electric start components - I kinda got myself into a corner. The stock kick start lever fouls the Hyde foot peg such that you have to mount it rotated underneath the peg. This would severely limit the total throw you'd get to kick it over. I didn't feel that would be very successful.
I just happened upon the RGM designed and manufactured folding kickstart (#050179 - based on a T160 design). In addition to being slightly longer (for more leverage), it also folded just perfectly to nestle in when folded and just clears the peg when out. It was made very nicely so, I think this solves the problem.
1975 Norton - Wiring Harness
I needed to create a new wiring harness for the bike. I had several upgrades/alterations in mind:
I also wanted to use the original Norton wiring color scheme as much as possible. I obtained the request wire, bullet connectors and sleeves from Britishwiring.com
Jere is my attempt the diagram.
I first ran the wires on the bike in the approximate locations of everything. I left a lot of extra on each end and didn't terminate anything yet. It took several go rounds to make sure I had all the wires run in the routes I wanted. I also added some extra ground wires in for the headlight, head, frame and rear tail.
Once I had the rough layout, I zip tied the thing together and removed it from the bike. I wrapped it in black harness tape and terminated with heat shrink. Then I remounted the loom on the frame and started cutting things to length and terminating. I slowly worked through the brake lights, head lights, indicator lights, turn signals (which took a while since I had to fabricate the mounts), and the ignition.
I forgot to take pics of when I wrapped it and installed it.
Anybody into Commandos will tell you that the bike was apparently built around the horn. The stock location is deep in the center of the bike, difficult to get to - not the greatest place for a horn to make sound. My original horn ended up being bad, so I needed to replace it. Further the original Lucas horn was probably everything Lucas thought it should be, which as it turns out, is pretty much the same as how they designed and built everything. So I wanted to upgrade to a pair of Fiamm Freeway Blasters located in a more strategic position .I also needed a place to mount my new fuse block, the Fuzeblocks FZ-1.
I decided to mount all this stuff aft the air cleaner, but in front of the battery. My first goal was to model the space in Fusion 360, so I could design a way to get everything located. Once I had that, I designed a sheet metal mount. It took about 5 iterations to get it to work.
Once I had a design, I used Fusion's sheet metal tools to create an unfolded 1:1 plan of the part. I glued this to a piece of sheet metal, then cut and bent it along the lines. Once I had it bent up, I welded it together and painted it.
Everything pretty much fit as I hoped it would.
Here's the thing partially wired. In order to mount it, I welded a could of pieces of angle to the battery tray and then attached some captive nuts to be used with some horizontal bolts to secure the horn mount (you can see a couple of slots in the picture above - bottom of the front rail). So the horn mount slips down on top of the rails and 4 bolts are inserted horizontally to secure it.
And here it is mounted up. I'm pretty happy with the way everything ended up. The horn relay is a bit cramped, but normally not a service item. Now on the the next part of the project - the wiring harness!
1975 Norton - Dash
I wanted to eliminate the 4 indicator lights in the '75 dash as I'm moving them to the headlight bucket per the earlier style. The original dash I had was also not in the greatest of shape. So, armed with Fusion 360 and a 3D printer I started working out a replacement.
I originally thought I would use the dash as good location for the neutral light. However, I ended up deciding to ditch the headlight switch in the headlight bucket and use that location for upgraded assimilator (voltage monitor). So, In the end, I deleted the hole. Once I had the 3D model where I wanted it, I committed to aluminum.
I think it came out pretty well. If I make another one, I'll work on getting rid of the tooling marks - I was a bit aggressive with some of my cuts given the relative lack of rigidity in the setup. However, I need to get this done, so I'm using it for now.
MIght be cool to paint it...
1975 Norton - Engine Rebuild
This is a long story. I originally sent my engine parts off for machining, but due to unfortunate circumstances, the work never got done and I got my engine back after many months. I let it sit for another 3/4 of a year and tried again. This time, with more success, but it still took 6 months to get everything back. It was worth the wait - Jim Comstock in Colorado does amazing work and everything came back like jewelry.
Starting with the crank and rods, then setting up the end play, add some sealant and bolt 'er up. To set up the end play, I used an old set of main bearings that I ground the OD and ID such that they just slip on. That way I could try various shims without having to heat up the cases each time. For final assembly I, of course, heated the cases to install the new bearings.
Next was the timing chain. Along with that was torquing the crank and cam nuts with a cut away cover in place.
Next up was the pistons and cylinders. I used the "Comstock Method" to compress the rings and assemble the pistons and cylinders. (See www.accessnorton.com/NortonCommando/installing-barrels-with-two-hands-and-no-ring-compressor.24859/) Worked great!
I had an oil pump around that looked pretty good and I rebuilt it. I noticed, however, it was for an older style outlet with the smaller diameter output flange. I had to file a bit more of it flat to get the flange to sit square.
I then installed a Comstock cam chain tensioner, checked the cam lobe timing and put together the rockers. (See norton-rocker-spindle-fix.html for more rocker fun!)
Mostly together (the head is not fastened - I'll do that after I get the block in the frame.
It's starting to look like something!
1975 Norton - Rocker Spindle Fix
I was in the process of reassembling my long disassembled '75 Norton 850 and found that one of the rocker spindles was a sliding fit in the ol' RH4 head. Another one was almost as loose. They're supposed to be more of an interference fit to the point you need to heat the head to get them installed. Among the host of issues that loose spindles can cause is allowing the spindle to rotate (it's supposed to be held in position by an absolutely poorly designed stop plate) and will allow a lot more oil to enter the rocker cavity. This, in turn, swamps the valve guides allowing oil to get sucked in and burned which results in massive amounts of smoke and plug fouling.
One of the better fixes is sold by RGM in England (https://www.rgmnorton.co.uk/buy/one-piece-rocker-spindle-locating-plate_4062.htm). It solves two problems actually, it'll keep the spindle from rotating, and it allows you to really lock it in place with the grub screw which should help keep it much more stable over the long run.
Since I am impatient, had some stainless bar and a CNC mill, I decided to whip up my own version of these. I think they came out pretty good.
And here's the final result. I think they're going to work very well.
1975 Norton - Paint
Finally in 2015, I decided on a paint scheme. I decided to use Vintage Vendor (Brent Budgor at http://vintage-vendor.com/) in Vermont as recommended by several folks on AccessNorton.com. I slightly modified one of his Commando themes and I was not disappointed. Here's the result mocked up:
1975 Norton - Z Plate Mod
Sitll in 2014, I guess I got the idea from Hobot (a frequent contributor on accessnorton.com) to drill holes in my Z plates. I ended up creating a pattern I liked and tested it out on my mill with a pen to make sure I had it correctly registered. Then I ran the program. I like it.
But things never go exactly according to plan. I sorta realized a bit late that there was a mounting needed for the rear brake pipe support that I just happened to have milled away. Oooops. I had to create a solution.
I realized I had left a very small part of the original hole that I decided to use. I then ginned up a sort of spacer to hold the bolt in this depression further aided by sandwiching it between a couple of washers. I first mocked it up with my 3D printer, then once I liked it, I machined one out of aluminum. I think the final product came out pretty OK. It holds the bolt securely and I think it looks interesting.
1975 Norton - Clock lighting
While I was on a roll in 2014, I got the idea to modify the speedo and tach to use LED strip lights. I found some red lights that were in strip format and rated for 12v.
I had to develop a way to remove and install the bezel. I ended up making a fixture to mount the tach or speedo to my lathe. Then I created a tool that I could mount on the cross slide to either unroll or roll the bezel on. I spun the chuck by hand slowly to accomplish the task. I don't have any pics of this process, but might update this with a few pics fo the tools.
I was interested in incorporating a diffuser of some sort so the light would be a bit more even. I ended up machining a couple of rings out of plexiglas to act as a diffuser.
Once I had that figured out, I mounted the strip - it's got adhesive on the back - added a electrical connection and closed 'em up.
The final outcome. I plan to add a dimmer knob somewhere for these.