Essential mods for your Norton Commando

Could someone advise me on a mod to stop my 1973 850 spindle oil leak....
I top up the fluid every year and it spends a few months slowly drooling out, mostly due to the motion of riding that
pivots the joint. I know I can live with it, but there is a satisfaction doing the job correctly.
Of course a mod that does not require me to pul it apart would be nice.
I saw the Kegler parts discussed but suspect they would not help...

Thanks
Dennis

DennisMo said:

Could someone advise me on a mod to stop my 1973 850 spindle oil leak....
I top up the fluid every year and it spends a few months slowly drooling out, mostly due to the motion of riding that
pivots the joint. I know I can live with it, but there is a satisfaction doing the job correctly.
Of course a mod that does not require me to pul it apart would be nice.
I saw the Kegler parts discussed but suspect they would not help...

Thanks
Dennis

Click to expand...

If the spindle is pivoting in the housing because the retaining bolt has fallen out or sheared off it would explain the leak, but it's likely the cradle would have to come out to fix, and the Kegler mod would be a good fix.
If you remove the end cap you should see if the spindle is static when the arm moves or seized to the swinging arm by bouncing on the rear suspension.
if that checks out its likely a knackered oil seal, which is easier, but will need the primary drive removing.
Either way, they aren't 5 minute jobs.
The standard setup is oil tight if everything is in good shape and 140W oil is used.

In the list of essential mods, if your Commando is running the original OEM Amals they need to be replaced. They were worn out in the first three months of ownership and will make proper tuning impossible.

The knackered Amals on my '70 were really flogged out - to the point that it wouldn't pull above 3k unless I held it at WOT, when it coughed a lot then took off like a scalded cat.
I replaced the throttle slides, needles & jets, and replaced the nylon float needles with viton tipped ones and it now runs perfectly, with a stable tick over.

I disagree that the carbs need replacing - it just needs to be understood that the throttle needles & jets wear out and badly affect performance, but are cheap to replace.

I once spent over a weeks wages on a new concentric for my A10. Within a couple of thousand miles A could hear the slide rattling and part throttle response was deteriorating. A new slide didn't help much as the body was worn too. I put the old monobloc back on and never looked back. The mk 1 concentric is a poorly designed cheaply made POS (but some people think they look good)

Andy Higham said:

I once spent over a weeks wages on a new concentric for my A10. Within a couple of thousand miles A could hear the slide rattling and part throttle response was deteriorating. A new slide didn't help much as the body was worn too. I put the old monobloc back on and never looked back. The mk 1 concentric is a poorly designed cheaply made POS (but some people think they look good)

Click to expand...

Ya just can't go wrong with a Monobloc but you have to be careful with the assembly and the float position. That said, the most trouble I ever had with Norton carbs was a pare of Monoblocs with the shared float bowl on an Atles.

B+Bogus said:

The knackered Amals on my '70 were really flogged out - to the point that it wouldn't pull above 3k unless I held it at WOT, when it coughed a lot then took off like a scalded cat.
I replaced the throttle slides, needles & jets, and replaced the nylon float needles with viton tipped ones and it now runs perfectly, with a stable tick over.

I disagree that the carbs need replacing - it just needs to be understood that the throttle needles & jets wear out and badly affect performance, but are cheap to replace.

Click to expand...

They do. All that stuff wears out but the carb bodies get beat to death by the slides and sometimes a new side is just a big sticking problem. I am glad they worked for you. They can be a right cause of frustration.

I guess I was lucky that the slide bores were still in good shape.
The new slides are anodised which I believe is a good thing to reduce future wear.
I did throw away the old carbs off my T140, which had done a huge mileage.
The PO had fitted them without the heat insulation spacers, and they were well warped!