Video of first run MKIII

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This is a video of the 1975 Norton Commando MKIII I bought a few weeks ago for $3500 US.

The sound on the video isn't the greatest, but at least it's running :D

I changed the MIkuni VM that was on the bike and put a Mikuni Flat Slide carb on. I think the flutter in the idle is because the pilot jet I chose is not the right one. Not sure which way to go on size up or down. I bought six pilot jets because the threads I read on Flat Slide carbs had a bunch of different sizes. I think the one I put in there is .027 if I remember right. I have smaller and larger ones so if anyone has an idea which way I should go, let me know.

I had to redo some of the wiring and it still needs work, but the bike started on the 3rd kick and hadn't run for a number of years so what you hear and see here is the first run in a long time...pretty amazing :D

Motor is strong and didn't even smoke when I started it. Quite happy with things right now because I have a good motor :D

[video]http://youtu.be/-PED95G0zhs[/video]
 
Snorton74 said:
I could listen to that all day. Sounds good and strong.

Love that sound...when it sprang to life it was like music...nothing like a British Twin :D
 
You got a basement bargain treasure find. Like a lullaby to us all.
That idle speed is good for actual runing about to keep ahead of the headlight when stopped for traffic. Its also good for the oil flow to cam/lifters. Its just on the cooler fuel burn side of too fast to cool down after a run or to get too hot sitting still before a run. What ya don't know about a Commando can hurt you or it. If ya not aware of primary tension and religious engine oil monitoring and front brake leaks or old miss aired tires on surprise hinged handling onset, oh oh. A thumb screw slide idle speed adjusters is really handy. Fiddle till the exhaust puffs feel about the same on each side then let the sound draw ya in.
 
Hobot,

I know many of those Notorn "quirks" having owned one new back in 1976. Also had two BSA's and a Triumph.

Miss matched or miss aired tires is a no-no on any bike BTW.

The Mikuni Flat Slide carb has a big slide adjusting screw on the left side that you can turn with your fingers. Love this carb. Throttle response is instant and it seems like I have the right needle and jet in there. Plugs are black so thinking the pilot jet is too big. It has air jet with adjusting screw also which is kind of cool but adds another adjustment that needs to be worked through. Jetting is the critical one though.

What I'm trying to get under control is a little "hunting" on idle. It will idle smooth for a bit then speed up and slow down. The tach is not working so can't tell RPM's which would be helpful in getting it set. May need to sort that out first.

I think I did pretty good for first shot with changing carb before I even ran the bike. I needed a new carb and went with the flat slide because people said it has better fuel delivery and response. There isn't much tech info on the MIkuni flat slide on a Norton. I'm pretty happy with the result tho...just want to fine tune it.
 
Oh shoot yours sounds really nice as is and double so to judge-jiggle that foreign Miki carb. If it wasn't so bad to slow idle I'd leave mine going below 500 all day long in the background. Those little missed beats are an advertising point of the 3 spark Powerarc ignition but i've heard em idle steady w/o missing beats on points and Boyah so you are on your own to diddle in better if even possible. Accumulations of a number of things have put my Combat down for the count till i get will power to take care of em all so appreciate your uplifting example i'm missing out on, again.
 
hobot said:
Oh shoot yours sounds really nice as is and double so to judge-jiggle that foreign Miki carb. If it wasn't so bad to slow idle I'd leave mine going below 500 all day long in the background. Those little missed beats are an advertising point of the 3 spark Powerarc ignition but i've heard em idle steady w/o missing beats on points and Boyah so you are on your own to diddle in better if even possible. Accumulations of a number of things have put my Combat down for the count till i get will power to take care of em all so appreciate your uplifting example i'm missing out on, again.

It has the old Boyer ignition. I'm surprised that you don't think I can get it better...maybe I'm trying to idle it down too much...sounds ok at faster idle. I don't like to run slow idle on and engine, because of lube issues, so thought I was fast enough but maybe not. I need to get that tach going so I can tell where I am.
 
speirmoor said:
Sounds good Den. Is the starter motor functional or missing?

The starter motor is missing. I've priced out the new style (4 Pole I think) and will replace it when I start the rebuild on the bike. My plan is to do a complete restore with a few Colorado Norton Works mods. I love the billet dash and guage panel Matt has.

I wanted to get the bike running so I could assess the engine. PO said it was professionally rebuilt about 1000 miles ago, but you don't know what's true until you get it running. I am pretty confident that is correct now that it runs. I will still go through the gear box, cluctch and such, but don't see any reason at this point to tear the engine completely down.

I could try and get her roadworthy and take her out and see what else is wrong, but not sure I need to do that because all the other bits will be replaced...tires, brakes, shocks, etc.
 
Denis its pretty good enough to me and loved how long you let us listen in. Its got tiny little stumbles that's pretty normal common in most engines. That idle sounds like 900-1000 so is about right for real life use in city type traffic. I set my idle down a bit lower 7-800 for listening pleasure but I don't have to sit in traffic so don't have todeal with low battery stall outs. Getting a nice low stable idle is a bit of an art with finer and finer diddles to various things.

The absolute best idle I've heard in Commando was the one I brought back from New Orleans a few weeks before hurracane got em. It came set up to idle at 400 on tach just a easy as ya please. When I got to the points checking, turned out one was slightly advanced and the other slightly retared off Combat 28', so maybe it worked like the zig zag idle stabalizing curves in some the electronic kits. My P!! came set to 600 rpm so that's where I left it not knowing any better then about cam lifter oil surfing speed.

May just try new plugs, which ain't a bad id anyway as I've had plugs half way foul while diddling an out of tune carb. Need a V8 set to do some plug chops on too. I got silence till I figure out Trixie's KS slippage fault.
 
I guess I'm a bit of a purist when it comes to tuning. I also haven't heard a Norton up close and personal since I sold my original MKIII back in 1978.

Then, with all of these improvements such as electronic ignition and better carburation...maybe I'm expecting too much. Was thinking there would be a huge tranformation compared to what they used to be. It certainly has quicker response when the throttle is popped.

The Dunstall pipes that are on there also contribute because they bark more than the pee shooters. Maybe I'm just hearing things :D

It actually sounds pretty good, and the video audio doesn't do it justice...seems to pick up the internal noise better than the actual sound.

I still have a few things to sort through that might improve it more. I am going to try the smaller pilot jet in there. The air adjustment seems to be somewhat sensitive and may need a little more finese to find the best setting. I think it needs new plug wires because the left side doesn't fit tight. I also need to sort the tach issue.

I appreciate all the comments and help. This site has been invaluable in figuring things out so far. I got the jetting info for the Mikuni TM Flat Slide here, and this was critical to get the carb on there and set-up right. It was basically plug and play even though I changed all the jets and the main needle...but that was because of the experience here.
 
I'm pretty sure Norvil, RGM, and Clubmen all make belt drives for an MK3, not that you need one. I was just curious.
 
dennisgb said:
speirmoor said:
Sounds good Den. Is the starter motor functional or missing?

The starter motor is missing. I've priced out the new style (4 Pole I think) and will replace it when I start the rebuild on the bike.
I have an Estart also thats why I asked. If the starter gear train is intact and all you need is the motor then you're in good shape.
 
There's a cover where the starter motor goes. I haven't taken it off yet to see if the gear is there...hoping so.
 
I put new plugs and plug wires on the MKIII today and running much better on idle. The plugs that were in there looked new, but decided to change them. The left boot was loose on the plug.
 
That's a real nice sound. How is it around 3K? Are they Dunstall silencers? My Wassal peashooters sound a bit ratty at 3K.

How about a video at 3K?

Trouble is mounting those silencers on an S model.

Dave
69S
 
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