Norton Commando 1969 timing issues

Status
Not open for further replies.
Migsan said:
Thanks for the help. I tried changing the stator plate already but I will check for the wires tomorrow to be safe. Today spoke with Boyer Bransden and they also suggested the following: "
The MK3 appears to have a reduced sensitivity to the signal.
If rubber mounted, check the earthing of the Norton's engine.
A bad earth can cause high voltage damage to the ignition unit, via the signal stator plate.
I will try and all of the suggested on the forum tomorrow
Click to expand...
Does your model have a ignition warning light in the headlight shell.
 
I hope he hasn't given up. It's not magic, it's just an issue.

I doubt he's got the ignition warning light in the shell, it's a 70. If it's stock all it's got is the ammeter, hi-beam warning, light switch (which includes the parking light).
 
DogT said:
I hope he hasn't given up. It's not magic, it's just an issue.

I doubt he's got the ignition warning light in the shell, it's a 70. If it's stock all it's got is the ammeter, hi-beam warning, light switch (which includes the parking light).
Click to expand...
Hi everyone
I haven't had time to look into the bike due to work. This evening I checked the engine earth and it was good. I am waiting for the new ignition to arrive to my friends house in the UK so that he can send it all to me. When that comes through I will also be able to check the compression.
Tomorrow I will try to check the valves more thoroughly like suggested before. On that same order I will receive the oil switch from madass as well to replace the high-beam warning light. I will see what I manage to do tomorrow and report back
Thanks
 
Migsan said:
Hi everyone
I haven't had time to look into the bike due to work. This evening I checked the engine earth and it was good. I am waiting for the new ignition to arrive to my friends house in the UK so that he can send it all to me. When that comes through I will also be able to check the compression.
Tomorrow I will try to check the valves more thoroughly like suggested before. On that same order I will receive the oil switch from madass as well to replace the high-beam warning light. I will see what I manage to do tomorrow and report back
Thanks
Click to expand...
DogT said:
I hope he hasn't given up. It's not magic, it's just an issue.

I doubt he's got the ignition warning light in the shell, it's a 70. If it's stock all it's got is the ammeter, hi-beam warning, light switch (which includes the parking light).
Click to expand...
Mine is a 70 with the ignition warning light. I have the same issues. I changed the warning light assimilator and it started 3rd kick no issues now.
 
What is the ignition warning light? There's no assimilator on a stock 70 that I know of. What Migsan has I don't know but he said he had 2 6V coils which points to stock 70. Don't the bikes with assimilator have 12V coils? Not that I'm the expert. Just EX.
 
DogT said:
What is the ignition warning light? There's no assimilator on a stock 70 that I know of.
Click to expand...
That should be correct for the majority of '1970' models as I believe the change to the electrical system (assimilator, charge warning light, ballast resistor, 6V coils, Lucas switch clusters, etc.) was part of the Jan. '71 model change (Fastback III etc.) at 141783.

DogT said:
What Migsan has I don't know but he said he had 2 6V coils which points to stock 70. Don't the bikes with assimilator have 12V coils?
Click to expand...

It's the opposite, so by rights, Migsan's "1969 S type" should have had two 12V coils originally as it should be pre-141783 serial number, however, although these change of specification serial numbers don't always seem 100% accurate 141783 is too late to be an S type.
 
Last edited:
Boy, am I confused now. First post said he was working on a 69 S type. I never saw an id number. That must have been somewhere else.
 
Sorry my bad. Yes it's the assimilator light the one that light up when the alternator stops charging the battery right?
My assimilator was long gone. The bike came with the boyer MK3 and two 6 V coils. The serial number is 132738 May 1969 (matching numbers).
It was exported to the US on the 23rd of May 1969 in a consignment of 92 commados on board of a vessel called American Legion :D.
I requested the despatch records from Andover Norton when I was living in the UK. This one ended up in the state of Indiana
 
Migsan said:
My assimilator was long gone. The bike came with the boyer MK3 and two 6 V coils.
Click to expand...

Your '69 S type would be too early to have had an assimilator. It would have had an ammeter and two 12V coils (and no ballast resistor).

The high beam warning light, however, was red on pre-'71 Commandos.
Norton Commando 1969 timing issues
 
Last edited:
RoadScholar said:
As has been mentioned in this episodic saga before, what goes downhill easily won't come up with similar aplomb. A Norton should start with the kick starter.

I applaud the steps you have taken to identify and rid your Norton of the gremlin(s); I'm also impressed with the suggestions contributing members have made to share their experiences without resorting to astrology, which, at this point, may be as helpful...

You need 4 elements to make an internal combustion engine run: 1) air, 2) fuel, 3) COMPRESSION and 4) a spark.

You stated: "I have no means of testing compression..."

Before you push this Norton down any hill or have a pair of pushing teams to assist YOU MUST CHECK THE F%$#ing COMPRESSION!!! A cheap compression tester will be more than worth its' weight in gold, can be purchased on-line and will tell you, even with a "cold" engine, if the cylinders have enough to fire the air/fuel mixture. You can get a credible idea by engaging 4th gear, bring one of the cylinders to TDC, having an assistant apply the rear brake while you apply about 20 PSI to te spark plug hole (applying more won't be necessary, and may harbor some degree of danger). If you have made a good seal on the spark plug hole you should be able to hear where the leak is; be sure that the ignition is off and that the fuel taps are in the off with the float bowls have been emptied.

Do not, under ANY circumstances, use a vacuum cleaner on the plug hole, most members know the story of a well meaning chap that went to change his spark plugs, saw the usual deutritius surrounding the now empty spark plug hole, gets his vacuum cleaner begins cleaning the deutritus and quickly discovers that the modest vacuum cleaner has become a flaming turbo-jet engine, duty it wasn't designed for, but the poor device did yeoman's service morphing into a flame thrower making the original task of changing spark plugs very moot as the car, the garage and the attached house turned into an insurance claim.

You said you set the valve clearance(s), how many threads were left showing above the jam nut(s)? The Ace that rebuilt the engine may have installed the pistons according to the marking (left & right), but ignored the reality of not noticing that the intake valves are closer together than the exhausts. I posted a picture ages ago showing one of my customers experience with this after paying a local mechanic to rebuild his Commando engine, which actually ran for 300 miles....

Buy a cheap compression tester, your sanity has to be worth more than what you have gone through.

Do let us know what the compression tester tells you.

Best.
Click to expand...
I checked the valve clearance again and it was spot on. Regarding the threads above the jam nut I count two on both the intake valves and three on the exhaust side (not counting the squared grinded ones where you secure the bolt). Is that correct?
Thanks
 
L.A.B. said:
Your '69 S type would be too early to have had an assimilator. It would have had an ammeter and two 12V coils (and no ballast resistor).

The high beam warning light, however, was red on pre-'71 Commandos.
Norton Commando 1969 timing issues
Click to expand...
Thanks L.A.B. I have the ammenter with the red light. I would love to post pictures but I need to figure out the photo bucket :)
 
Ah, ha, so it is an early bike. Mine is Apr 69, 132031. So I guess I've forgotten about the coils, must be the age at least I can blame it on that or the Jamesons. I never knew the word assimilator until I came to this forum. I'm still not sure what it is, other than maybe a resistor. It sounds kind of like a 'flux generator' that may need re-calibrating, but I jest. I never saw the purpose in it other than bad or cheap engineering.

At least it got out of Indiana.
 
DogT said:
Ah, ha, so it is an early bike. Mine is Apr 69, 132031. So I guess I've forgotten about the coils, must be the age at least I can blame it on that or the Jamesons. I never knew the word assimilator until I came to this forum. I'm still not sure what it is, other than maybe a resistor. It sounds kind of like a 'flux generator' that may need re-calibrating, but I jest. I never saw the purpose in it other than bad or cheap engineering.

At least it got out of Indiana.
Click to expand...
z3ro said:
Your ‘S’ is only 192 bikes after my ‘S’ 546 in may
Click to expand...
Did you guys still have the original fiberglass tank or you changed it for the metal one? Mine seemed to be the blue originally but I ended up painting it black.
 
I've still got the fiberglass tank. Orignially blue. At one point I stupidly painted it black but I finally repainted it a flake blue. I use non-ethanol gas in my tank.
 
Migsan said:
Did you guys still have the original fiberglass tank or you changed it for the metal one? Mine seemed to be the blue originally but I ended up painting it black.
Click to expand...
It was changed to metal and painted fireflake
 
Status
Not open for further replies.
Back
Top