Adventures in Commando land...time for an update

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rvich

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It is time to get something posted here. The list of questions might get too long otherwise.

Back in August I posted that I had aquired a Norton after a long hiatus. Since I am in Alaska, the bike was sitting at a rely's house in Portland awaiting my arrival to figure out what to do with it.

The opportunity to mess with the bike came during the last few weeks when I traveled south for a family reunion and wedding. This is not a perfect situation for sorting out a bike that was last tagged in 1990. I have no idea how long it had really been since the bike had been run.

The bike is registered as a 1973 750. It is an interstate model. Now I say "registered" because one of the first things to note is that the plate on the frame says it was manufacuted 4/73 and has a number 302XXX stamped on it, but the motor and gearbox both have a 206XXX number.

Of course one of the first chores was to change out fluids. Now as I said it had been a long time since spending any time around a Norton but I had expected to find either a filter cartridge between the swing arms, or a large hex-head plug on the bottom of the crankcase for a filter. To my surprise I found neither one. I was also under the impression that a frame of 1973 vintage would have a tab that the spin on filter would have been secured to with a clamp. Didn't find one of those either.

I won't go through the entire event of getting the bike running. I was tempted about a million times to get on here and ask questions (help!) but each time knew there was something that I had missed, or more importantly failed to think of. So, I went through the process of ignition, carbs, timing, and back over each when it wasn't quite right or in some cases refused to run at all. There was a period when things got worse isntead of better. All the help from the gathered crowd was not always a bonus and more than once my normally keen sense of humor was absent. Like about the hundreth time somebody asked why I didn't buy a bike with electric start.

Eventually, I tucked my tail, boxed up the bike and shipped it home where I could at least work on it in peace and quiet. Well yesterday I finally got to go for a decent ride! During this whole process I solved a number of small issues, some of which where creating quite a bit of trouble. Like a crack in the phenolic washer on one point set that seemed to cause an intermitent short to ground and was really found only through luck.

The ride was great! Other than the fact I ended up doing so without any lights. When I finally got the tuning to where the bike would sit and idle, I finally got a chance to try out the kill switch. I punched a few buttons until one of them shut down the bike. The first thing I noticed was that the red indicator lamp on the headlight shell didn’t come on as normal. I started the bike back up and the lamp momentarily lit. Then after warm up it came on intermittently while idling and would go out when RPMs increased. I seemed to remember this being normal on my old bike, so I shrugged and turned the key to the lighted position. The motor instantly died.

I think it is obvious there must be a short somewhere and no I haven’t gone through the process, yet. Prior to this event the headlight worked without fail despite the fact that I couldn’t keep the bike running. But I noted that the fuse on my negative lead from the battery is blown. So here is my next question. Will the bike start off its capacitor and then run off its alternator without that fuse? If so, then the capacitor must be getting charged from the alternator despite the blown fuse because I can repeat the start without difficulty.

The good news is, the bike is starting easy, so at least I don’t have to listen to a bunch of nay-sayers giving me a bad time about no electric start!
 
The bike is registered as a 1973 750. It is an interstate model. Now I say "registered" because one of the first things to note is that the plate on the frame says it was manufacuted 4/73 and has a number 302XXX stamped on it, but the motor and gearbox both have a 206XXX number.

I can't find the online reference for serial numbers, but 206 is certainly pre-73. It seems that the drive unit (engine, gearbox, cradle, swingarm) was replaced with an earlier unit that didn't have the oil filter or sump screen.
 
I seemed to remember this being normal on my old bike, so I shrugged and turned the key to the lighted position. The motor instantly died.
I think it is obvious there must be a short somewhere and no I haven’t gone through the process, yet.

Most likely the keyswitch is corroded and not making contact in the "light + run" position. You can carefully disassemble the switch, being carful not to lose the springs and metal balls and clean the contacts and reassemble or buy a new one. DomiRacer has their reproduction on sale for $18.71 with lock and keys. I have found this to be as good as the original Lucas ones which are $80 without the lock. Alternatively I have seen other keyswitch assemblies used but they may require some thought and re-wiring as many are three-position rather than four. You may need to use the headlight toggle as an off/on switch, etc.
 
Thanx for the thought on the ignition switch. I hope to get some time to mess with it this weekend, but I have about a million things going right now. I will try to get some pics posted as well. In reference to the engine number, I guess it never really occured to me that this might be a Combat engine.
 
sugest you post all the numbers ie frame # engine # and gearbox # they all should match but hopefully frame and a nother will tell whats been changed.
regards Al
 
Well, for what its worth. Here is a pic of the bike.
 

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A Norton frame stamped 302xxx is definitely a ''73 850 (My 850 is 303xxx and is also stamped 4-73)

A Norton Engine and gearbox stamped 206xxx is definitely a '72 750.

Looks like you've got a 'bitsa'
 
Interesting and nice looking bike. Noticed the clock holders, and tail light, a 72 :?: I would relocate the horn somewhere else. Nice backgound to take a pic of that Interstate.
 
I have been wondering about that horn...I could relocate it to the handle bars and put tassles off the grips, or maybe it would be better relocated to the spares! It has such a large diameter that finding a good spot for it might be a challenge. Let me know if you fancy it, perhaps we can negotiate a trade!
 
I thought, until now, that the stock location couldn't be worse. Incredily difficult to get to.


But, not to be too much of an American here I hope, that looks like ShITE. NO offense meant. It just does.
 
Personally I think it's just on the wrong bike, or perhaps in the wrong location. We all formed our ideas about what these should look like a long time ago. On a Harley, say, or hidden a bit it would be fine.
 
The horn says (in English) "made in France" and is a Sanor. Maybe I could sell it to the BMW crowd!
 
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