1973 Norton Commando 750 restore

fumanchew · Nov 7, 2013

Hello,
I recently acquired a 1973 Commando 750 VIN 235072, it had been sitting for years and we just got it started. The right muffler exhaust output is generating cool air, the left has heat to it. Anyone know what is causing this? I ordered restore/repair manuals but they haven't arrived yet. Also have quite a bit of oil coming out from the rear tire chain area, a friend said it may be a chain oiler/regulator issue.
Would appreciate your help,
Thank you

Rohan · Nov 7, 2013

Welcome.

Amal carbs left sitting for a long time tend to gum up their idle passages inside, so it won't run at low revs on that carb.
Sounds like one carb is gummed up. ?

Could be spark plugs though.
Tried new plugs ?

Bikes left sitting unused for long slabs of time tend to drain all their oil (from the oil tank) down into the sump.
When you start it up, and the sump is full, it pukes oil out the breather.
Sometimes lots of oil.
Drain the oil from the sump (put it back into the oil tank, if its clean enough), and see if it still pukes oil out.

If it burns lots of that oil that was in the sump, it may oil up a plug or 2 also.
Once its ridden on the road, this will hopefully all settle down.

Have fun !

dennisgb · Nov 7, 2013

Does the header pipe on the right get hot so you know it's firing? That's the first test.

If it's been sitting for a long period all the things that Rohan said above come into play.

Also, does it have points or has it been converted to electronic ignition? Points could be corroded after all that time. All wiring connections for that matter.

kevbo82 · Nov 7, 2013

my 73 sat for about 20 years, i changed all the fluids and plugs to get it started and had much of the same. Thousands of dollars later in restoration and multiple cleaning's/rebuilding's of the original amals, one of them was just always off and i couldn't seem to get the idle passage clean enough. A new set of the amal premiers did it justice.

fumanchew · Nov 10, 2013

Thank you all for your support and guidance, got the bike running thanks to your expertise, need to figure out how to tune the carbs. I got some suggestions on how to do it manually, turn clock wise on fuel mixture until runs rough, then back up a quarter turn for both sides. How does that impact the idle adjustment, should I be ready to tweek both adjustments?

Regards,
FMC

L.A.B. · Nov 10, 2013

fumanchew said:
need to figure out how to tune the carbs. I got some suggestions on how to do it manually, turn clock wise on fuel mixture until runs rough, then back up a quarter turn for both sides. How does that impact the idle adjustment, should I be ready to tweek both adjustments?

http://www.jba.bc.ca/Bushmans%20Carb%20Tuning.html

fumanchew said:
1973 Commando 750 VIN 235072

It's another one of those mysterious "235" series Commandos.

fumanchew · Nov 10, 2013

Thank you for the link, I'll probably put out the coin for a new set of carbs considering previous posts on this issue.
You guys are golden, thanks again.

kevbo82 · Nov 13, 2013

don't forget you can buy the amal's (if thats the route you go) right here on the access norton store.

fumanchew · Dec 10, 2013

High beam indicator light went out, found replacement bulbs online but how do I get to the bulb in the indicator sleeve? Couldn't find any mention of the 3 indicators (high beam, turn signal and ignition mounted on top of headlight) in the shop manual, but they are shown in the schematic drawing.

L.A.B. · Dec 11, 2013

fumanchew said:
how do I get to the bulb in the indicator sleeve?

If it's the standard Lucas type, then the bulb holder (with tags or wires) should just pull out of the indicator body.

fumanchew · Dec 11, 2013

Thank you for the heads up. I got the indicator bulb out, amazing how crude electrical technology was 40 years ago, the lamp holders were crusted stuck to the outer shield. BTW, where did you get the Blue Shield?
I changed out the turn signal paddle, even the shop manual made mention of the difficulty involved with working on the unit. That electrical/mechanical switch doesn't make much practical sense at all, duo cam plastic paddle, duo contacts and a spring-ball bearing design that is housed in a channel. Whatever happened to Keep It Simple, engineers justifying their salaries I guess. Then again, even today England is not known to be electrical/electronic leaders in the industry.

L.A.B. · Dec 11, 2013

fumanchew said:
BTW, where did you get the Blue Shield?

The photo is from the Internet, but any good British bike/car/Lucas parts supplier should have them.

YING · Dec 11, 2013

+1 on dealing with Jerry at the AccessNorton store.Great service and very helpful.
YING

Matt Spencer · Dec 11, 2013

" where did you get the Blue Shield? " Life was simpler then , you just looked at the head of any traffic jam .

a White MORRIE 1100 . :lol: - before white jap vans took over this role .

Most english cars around 70 had Lucas stuff , so austins , Morrises , some Hillmans etc have them .
Wriggle or heat gun / before removeing , if brittle . :?
the Old Humber 80s & Hillman Minxes , etc etc etc , so dates to 50s if youre after a phycodelic aray .

fumanchew · Dec 20, 2013

Thank you Mr. Spencer, got the lamps out okay and installed replacements. Also mounted a Corbin Smuggler on the Norton, I like the way it looks and it comes with a small trunk.

1973 Norton Commando 750 restore

fumanchew

Rohan

dennisgb

kevbo82

fumanchew

L.A.B.

Moderator

fumanchew

kevbo82

fumanchew

L.A.B.

Moderator

fumanchew

L.A.B.

Moderator

YING

Pittsboro,NC

Matt Spencer

fumanchew

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