A late 72 journey out of hibernation (2020)

I would look at your cable routing to see if the slides are hanging up at all. Pull off the air cleaner to watch and verify as you twist the throttle.

Check to see that the Amal carb tops are correctly oriented, with the choke hole to the rear of the bike.

I have had both of these give erratic idling.
 
I will triple check those items, thanks . I'm kind of a cable routing fanatic I worked best routes VERY carefully when I installed the new throttle cables on the old carbs. Yes tops are oriently correctly. Since I can drop the idle with a slight clutch release and it then stays low, and I can feel the slack, slides touching the stops, I'm thinking not cable issue. Will pull the tank go to a test tank and do some timing light work and most likely change to the electronic ignition to eliminate a possible hanging advance issue.
Thanks again all.
Did some searching last night but found little current info on good rear shocks, these are way stiff and need replacement.
I'm about 180 geared up, will not have a pillion rider, roads are "not billiard table smooth" round these parts.
 
Full day in the shop.
Most of it replacing the points and mechanical advance with the Wassell Vape ignition.
Wiring directions were good a couple pics would have helped with the rotor stator timing install directions.
A hint; though the rotor rotates "clockwise" you need to use the A, "counter clockwise" timing mark on the stator.
My initial static advance ignition setting was about 2 degrees retarded from 28 ie 26 when checked with the timing light, going to leave it there for now.
With the condenser holder and ballast resistor not needed and removed, I moved the coils inboard inside the captive nuts instead of outside giving me much better access to the front tank bolts making tank on off a lot easier.
Aaaannnddd.
Hanging idle is cured. Woo Hoo.
Full disclosure I did also reroute the front cable (again), reset the carb top adjusters to match.

Since it was raining about the time I got the iggy done. I pulled the caliper, pushed the pads back, cleaned the exposed piston bores, used a BIT of brake fluid as lube exercised them a few times, sanded the pads, reinstalled. A very noticeable improvement. My theory is that one pad was "immobile" braking effort was mostly warping the rotor instead of stopping. Only a short ride so far but suspect it will remain much better than it was. That'll do 'til I get to the full monte brake rebuild.
Thanks for the suggestions!
A late 72 journey out of hibernation (2020)


A late 72 journey out of hibernation (2020)
 
Last edited:
gggGary said:
A hint; though the rotor rotates "clockwise" you need to use the A, "counter clockwise" timing mark on the stator
Click to expand...

The rotor (and the camshaft it is attached to) rotates counterclockwise (or 'anti-clockwise').

"IGNITION TIMING FOR BRITISH TWINS
TRIUMPH TWIN CLOCKWISE 38 degrees fully advanced
BSA TWIN ANTI CLOCKWISE 34 degrees fully advanced
NORTON COMMANDO ANTI CLOCKWISE 28/31 degrees fully advanced
NORTON ATLAS CLOCKWISE 28/31 degrees fully advanced"
 
Last edited:
I need a chain, can I use DID #50 (non o-ring)? The side links on the chain in there now are on the thin side, ie the chain is narrow is there a maximum width spec for chain? I see o-ring chains are a no no (bummer) No doubt will replace both sprockets next winter but for now the chain is stretched and needs replacing.
 
It's on the lift, gotta bunch of stuff to do "up front"
The debate rages about using a pair of wheels I grabbed. They are new and 25 years old, 18x2.50 Akront, Buchanan SS spokes, bearing are shot. Tires suitable for test use only. Has an unusual rotor adaptor and what looks like an aftermarket Harley flat 5 bolt rotor.
A late 72 journey out of hibernation (2020)
 
Eveeything was sitting in a " shed". might just be rock hard grease but prolly worse. New parts on norton hubs no idea if bearings were changed or???. Rear rim is pretty nice, front has some pitting that won't polish out.
 
gggGary said:
Hi I'm Gary and I'm a Nortohaulic. :cool: It's been 40 years since my last Commando but I just fell off the wagon. Purchase was more emotional than logical and with a bit of legerdemain on the seller's part I should have walked away, but NO. Hauled it home.
It had been in one family since 1985, lived on a small island, got little regular exercise, the clock shows 13,900 miles 300 of those since a motor overhaul in 2016 bore, pistons etc. Bike came with 15 years of records, receipts, been through those once quickly. It readily started and ran through the gears a mile up n down the rural road. Forgive me if the PO is here, he was more of a romantic than a mechanic, most work had been performed by shops, located a ferry ride and 100+ miles away. Have other bikes, don't NEED to ride right this right away but, well you know...
So hoping to share and gain insight from the fold on how to proceed. Let's say it's been living in benign neglect. Somewhat tatty, a ten footer, would be a fitting description.
Got a photocopy workshop manual with the bike. Will set valves. Put the camera in the holes. Try to get through a basic wake up maintenance.
Any help, suggestions, and even you maroon! comments welcome.
Will need to determine if it has combat spec parts. Heard rumors of a C mark on the head somewhere? Can cam lift be checked at the lifter?
Currently compression is 130, 145 after about 5-6 kicks throttle open with a gauge I know and trust. A glam shot with one of my Xs650s.
A late 72 journey out of hibernation (2020)
Click to expand...
You realize at that mileage it's time to check those work records for the layshaft bearing change . It's essential.
 
As these things go; day 4 of the "wheel change"
A late 72 journey out of hibernation (2020)

Steering bearings removed cleaned reinstalled. Races looked good yet. I'm a Tungsten disulfide guy so some got dusted in before the grease.
A late 72 journey out of hibernation (2020)

Hard to stop "cleaning up" forgings.
any rattle can paint recommendations?
 
gggGary said:
As these things go; day 4 of the "wheel change"
A late 72 journey out of hibernation (2020)

Steering bearings removed cleaned reinstalled. Races looked good yet. I'm a Tungsten disulfide guy so some got dusted in before the grease.
A late 72 journey out of hibernation (2020)

Hard to stop "cleaning up" forgings.
any rattle can paint recommendations?
Click to expand...
If it's alloy, clean with paint thinners and use etching primer beforehand. Paint under coat then any colour you like.
 
I'm with you TomU but these aren't all that critical.... Did Norton ever publish a "out of straight" spec on fork tubes? Didn't find any in the copy of the service manual I have. I'm getting about .005" out just above the slider when checked between centers in the lathe.
I'll check closer when I have the tubes separated. This is about the limit spec from a Yamaha manual of the period.
 
Back
Top