Greeting from a New Member and Norton Newbie

Hello to all,
this is Cliff from Southern California. I have just acquired a 1974 Norton Commando. This is a bike that I have wanted for a long time. I had a few Triumphs when I began riding many years ago, but never a Norton. I have been riding Guzzis and a Ducati for the past few years, and this Norton is a real blast. It is bringing me the type of joy I remember from when I first began riding!
This place looks to be the fount of knowledge for all things Norton, and I am happy to have found you and to be here. I hope that I will be able to contribute in some way.
I do have a question. I had the bike for a few weeks, riding it everyday. I just returned from 10 days away, and sure enough the engine is wet sumped and the oil in the tank is down below the screen at the bottom. I have been reading about wet sumping and I understand what it is. But for draining the engine case, is the practice to drain from the large plug for the crankcase strainer, or from the smaller more forwardly placed drain plug? Also, is anyone currently making the large crankcase strainer plug with the small drain plug in the middle? I saw it on the Old Britts website but it looks like they have closed up shop.
Also, the bike handles great, but when taking my hands off of the bars it wants to slightly drift to the left. The tires are new, the rims look good and the wheels look to be aligned……any advice on what to look for? Would a fault or misadjustment in the isolastic system cause this? The bike has evidence of a lowside but the frame looks fine, but I am certainly not an authority. I hope you guys don’t mind my questions. This is my first Norton rodeo.
Thanks!

Welcome.
Lot's of collective knowledge here.

Also, tell us about your mechanical skillset, it'll help us aim the right info your way.

Ever rebuild an engine?
Chain & sprockets?
Change your own tires?
Successfully repair an ailing carburetor? Mikuni? Holley?
You have Geese & Ducs.... envious!

Put the bike on the center stand, pull hither & yon on the wheel, sight against mufflers... 1/4"? 1/2"? Less?

If you've checked wheel alignment, well, possible something is a little bent.

A CLOSE VISUAL inspection of the frame can give more clue.

Welcome.

Kane said:

But for draining the engine case, is the practice to drain from the large plug for the crankcase strainer, or from the smaller more forwardly placed drain plug?

Click to expand...

You can use either.

Kane said:

Also, is anyone currently making the large crankcase strainer plug with the small drain plug in the middle? I saw it on the Old Britts website but it looks like they have closed up shop.

Click to expand...

Yes, they are available from other suppliers such as Andover Norton, etc:

Kane said:

Also, the bike handles great, but when taking my hands off of the bars it wants to slightly drift to the left. The tires are new, the rims look good and the wheels look to be aligned……any advice on what to look for? Would a fault or misadjustment in the isolastic system cause this?

Click to expand...

A normal Commando characteristic (mentioned in the NOC Commando Service Notes) supposedly caused by the disc brake being on the right-hand side of the forks which can be cured by moving the brake to the left-hand side (by swapping over the fork legs and reversing the wheel) which was what the factory did on the 850 Mk3 but replaced the threaded bearing lockring with a circlip as the original lockring could potentially unscrew if the pre-Mk3 hub/wheel is reversed.

Or, just keep at least one hand on the bars.

Kane said:

I hope you guys don’t mind my questions. This is my first Norton rodeo.

Click to expand...

Certainly not.

Hi Kane ...Welcome
There are many ways to mitigate the associated issues of wet sumping ...here's some... you maybe looking for.

Thank you, concourse, for your welcome and advice. Pulling back and forth on the rear wheel I’d say there is at least a good 1/2” of flex. It’s not sloppy loose, but it does move back and forth when the wheel is pulled on. First time I’ve ever seen that on a motorcycle, kind of cool. It must be a Norton thing. Even the wet sumping is kind of cool to me, coming from Guzzis that carry the oil in the sump.
Btw, as you like Guzzi and Ducati, I sold my Duc Hypermotard, a great bike, but I still have my Guzzi V11 and 850-T3. My first ever motorcycle back in high school was an 850-T, so I have a soft spot for these bikes. But I am really liking the Commando. It’s an exciting bike. I’ve stalled it a few times coming off the gas to a stop, and pushing it to the side of the road to kickstart it is an adventure! It’s a handsome steed and a lot lighter than the Guzzis. Really a nice compliment to, and change from, what I’ve been riding.
My skills are moderate. I have rebuilt carbs, Amals on my long gone Triumphs, I am good adjusting valves (not so much Ducati Desmo valves, though), oils, chains, and basic maintenance. I’ve not performed much surgery yet, but am up for what ever may come along. I expect that Norton ownership/stewardship in a bit more demanding than many bikes, and that’s okay.
Cheers!

L.A.B. and KiwiShane, thank you very much for your detailed address to my questions, and the links to the wet sumping. This engine and gearing on this bike are so nice. I am looking forward to sorting it out and making the bike better than it is. I was wanting an old school real motorcycle, and I welcome any rewarding tasks and projects that may come along with it. I’ve had modern two wheel cars before, and am turned off to them for the most part, although I will tolerate my V11’s fuel injection as that is a pretty fun bike, albeit it a bit overweight. And I have a garage to work in.

Thanks for the clarification of the tendency of the bike to drift left. What a trip. It‘s not too bad, really, but doing the hands free coasting, I do have to shift to the right a bit. It’s a great handing bike and feels pretTy good overall.

Kane said:

Pulling back and forth on the rear wheel I’d say there is at least good 1/2” of flex. It’s not sloppy loose, but it does move back and forth when the wheel is pulled on.

Click to expand...

It's possible the Isolastics are in need of adjustment either by re-shimming the assemblies or re-setting the clearances if the original Isolastics have been replaced with the easier-to-adjust vernier Isolastic conversion kits.
I assume you might already have a copy of the factory manual (there's no actual '1974' manual).

If not then here's an online copy.

'1974' spares supplement (assuming it is an 850 Mk2/2A model):
http://www.tioc.org/partsbooksnorton/pb-nort-850MK2-2A 06-5988.pdf
Note that the Mk2/2A supplement has no drawings so the Mk1 drawings have been added to it.

Thank you, L.A.B.
I‘ll read up on and check the isolastics. I have no idea if they are OEM or aftermarket. Thanks for the links for the manual and spares supplement and info, much appreciated! I actually have hard copies of the workshop and parts manuals on order from Century Cycles, where I bought the bike, but I need to get back there to pick them up. If you are ever in Southern California you might like to visit that shop. It’s a third generation family shop, an old Brit bike dealership. There are five Vincents there, including a Black Lightening.

When you say 1/2" play when pulling on rear wheel, is that at the top or rear of the tire or at the hub/swing arm point? There can be play from the SA pivot to the engine cradle plates for excessive wear btwn pivot spindle and the plate tube. Typically happens from neglect or use of grease at the "grease" nipple instead of using the spec'd oil at that fitting. The spindle bearings are oil absorbent, known as "Oil-lite" and must never see grease, which clogs their pores and prevents further lubrication.
Play can also be poorly adjusted isolastics at rear, front or even headsteady if rubber "Spools" are perished. Also, the centerstand can be worn at its pivot within engine plates, so be sure you are seeing wheel play relative to some fixed frame member (like the alloy "Z" plates and not just the ground to distinguish CS movement.

Watch out for wet sumping. My '850 does a full drain within a week, so that oil level is below the filter screen bottom of tank, thus no oil into pump until enough gets pumped back out of sump into tank. Starting with good oil load in the sump caused my crank seal, primary drive side, to blow in half, filled primary with engine oil in a 15 min ride, until it spewed out the drive sprocket opening, oiling the rear wheel nicely.

Kane said:

Thank you, concourse, for your welcome and advice. Pulling back and forth on the rear wheel I’d say there is at least a good 1/2” of flex. It’s not sloppy loose, but it does move back and forth when the wheel is pulled on. First time I’ve ever seen that on a motorcycle, kind of cool. It must be a Norton thing. Even the wet sumping is kind of cool to me, coming from Guzzis that carry the oil in the sump.
Btw, as you like Guzzi and Ducati, I sold my Duc Hypermotard, a great bike, but I still have my Guzzi V11 and 850-T3. My first ever motorcycle back in high school was an 850-T, so I have a soft spot for these bikes. But I am really liking the Commando. It’s an exciting bike. I’ve stalled it a few times coming off the gas to a stop, and pushing it to the side of the road to kickstart it is an adventure! It’s a handsome steed and a lot lighter than the Guzzis. Really a nice compliment to, and change from, what I’ve been riding.
My skills are moderate. I have rebuilt carbs, Amals on my long gone Triumphs, I am good adjusting valves (not so much Ducati Desmo valves, though), oils, chains, and basic maintenance. I’ve not performed much surgery yet, but am up for what ever may come along. I expect that Norton ownership/stewardship in a bit more demanding than many bikes, and that’s okay.
Cheers!

Click to expand...

All bikes suffer the usual worn swing arm bushings.
The pre-MkIII Norton Commando has a poorly designed pivot pin arrangement, easily solved with the https://www.accessnorton.com/NortonCommando/heinz-kegler-swing-arm-modification.11058/

Isolastic play shows as well.

Welcome to the forum.

If you keep up regular maintenance the Norton can be a very reliable bike and only usually small things will fail over time from wear and tear and they don't mine being pushed hard, in fact they like being ridden hard, well mind does and the good thing they are easy to work on, well I think so been doing it for 47 years with mine, although I converted my 850 to a Featherbed frame but over 70% is Commando gear.
Anyway welcome to the club and enjoy your new toy, but we won't believe you till we see pics lol.

Ashley (from down under)

I just drained the sump and refilled the oil tank. The bike fires on the first kick, and the oil cycled back immediately. I don’t have a 1.5” socket, so I removed the small drain plug. No metal on the magnet, and the oil looks good (it was changed when I got the bike), so back into the tank it went. There was some plumbers tape on the threads of the drain plug, along with a crush washer. Is plumbers tape on drain plugs an acceptable practice? I’ve not heard of that. Cleaned up the plug and put on a fresh crush washer and no plumbers tape, and gave it a moderately firm tug as I didn’t see any torque spec in the manual for the drain plug. The engine case is dry on the bottom, but the gearbox is oily on the front side. Supposedly the engine was rebuilt a few years back with standard size OEM cylinders and pistons, but I think the gearbox may need attention to gaskets and seals. The bike shifts smoothly in all gears and the clutch feels really good, although it’s a bit heavy on the initial pull. It looks like I am getting a nice little list of stuff to sort out. The next time that go away I will siphon the oil from the tank and refill when I return, unless I get around to the improvements for wet sumping that you all are referencing. In the meantime I’ll happily ride the bike daily.

Tornado said:

When you say 1/2" play when pulling on rear wheel, is that at the top or rear of the tire or at the hub/swing arm point? There can be play from the SA pivot to the engine cradle plates for excessive wear btwn pivot spindle and the plate tube. Typically happens from neglect or use of grease at the "grease" nipple instead of using the spec'd oil at that fitting. The spindle bearings are oil absorbent, known as "Oil-lite" and must never see grease, which clogs their pores and prevents further lubrication.
Play can also be poorly adjusted isolastics at rear, front or even headsteady if rubber "Spools" are perished. Also, the centerstand can be worn at its pivot within engine plates, so be sure you are seeing wheel play relative to some fixed frame member (like the alloy "Z" plates and not just the ground to distinguish CS movement.

Watch out for wet sumping. My '850 does a full drain within a week, so that oil level is below the filter screen bottom of tank, thus no oil into pump until enough gets pumped back out of sump into tank. Starting with good oil load in the sump caused my crank seal, primary drive side, to blow in half, filled primary with engine oil in a 15 min ride, until it spewed out the drive sprocket opening, oiling the rear wheel nicely.

Click to expand...

That sounds bad. I was gone for 10 days between when I rode last and later checked the tank, and, like you are describing, the oil level in the tank was below the screen. So it’s happening in 10 days, or perhaps less. Until I can improve this, as it seems that it can be helped, I’m planning on being diligent with monitoring the oil tank.

The play that I am seeing is at the rear sprocket / hub, looking down from the fender‘s edge to the tire, and the chain to the exhaust pipe. The 1/2” is a what It looks like, maybe a bit more, but I’ll revisit it and try to get an accurate measurement.
Thank you for the tip and info on avoiding grease at the nipple!
This is a 50-year-old bike with much of its history unknown. I wish I had a proper bike stand to get it off the ground and give it a thorough inspection and treatment.

Kane said:

Is plumbers tape on drain plugs an acceptable practice?

Click to expand...

It was obviously acceptable to the previous owner.

Kane said:

the gearbox is oily on the front side.

Click to expand...

Probably leaking from either the camplate or quadrant spindle (past either or both item '25' O-rings)...
Item 25 (x2).

...but I suggest you check the gearbox hasn't been overfilled if you haven't already done so.

concours said:

All bikes suffer the usual worn swing arm bushings.
The pre-MkIII Norton Commando has a poorly designed pivot pin arrangement, easily solved with the https://www.accessnorton.com/NortonCommando/heinz-kegler-swing-arm-modification.11058/

Isolastic play shows as well.

Click to expand...

Thanks for the link to that info. I can see that there is a good Norton community!
I want to say thanks so much to all of you for the warm welcome and for sharing all of this great knowledge and information. I have really learned a lot in the past few hours!
Cheers

L.A.B. said:

It was obviously acceptable to the previous owner.


Probably leaking from either the camplate or quadrant spindle (past either or both item '25' O-rings)...

Andover Norton Parts Drawings - Genuine Andover Norton Factory Parts - Commando Parts

Andover Norton Parts are the only Norton spare parts in the market manufactured to original drawings, within the factory-approved tolerances, from the correct materials, and with the correct finish.

andover-norton.co.uk

Item 25 (x2).

...but I suggest you check the gearbox hasn't been overfilled if you haven't already done so.

Click to expand...

Thanks for that. I changed the gearbox and the primary oil and filled to the level plugs when I fist got the bike, but I didn’t measure how much of the old oil came out. The level plugs seem to make filling correctly pretty simple and straight forward, but people got their own ways of doing things.

It's a learning curve and your journey has just started.

ashman said:

If you keep up regular maintenance the Norton can be a very reliable bike and only usually small things will fail over time from wear and tear and they don't mine being pushed hard, in fact they like being ridden hard, well mind does and the good thing they are easy to work on, well I think so been doing it for 47 years with mine, although I converted my 850 to a Featherbed frame but over 70% is Commando gear.
Anyway welcome to the club and enjoy your new toy, but we won't believe you till we see pics lol.

Ashley (from down under)

Click to expand...

Ashley, your bike sounds great and pretty interesting. That’s interting that the engine will go in a Featherbed frame. I have heard for years how great those frames handle.
Okay, I just posted pics in the picture threads. You can see her there, warts and everything wrong with her! She may be a little ugly and unconventional, but I dig her.
Thanks for your warm welcome! Your blue tank looks great, that is a nice shade of blue.

Nothing wrong with ugly as long as it goes greats and you can pretty it up as you go, but me I am different my Norton has been well ridden most of its 47 years of ownership and was my everyday rider till 2013, now I am retired and the Norton semi retired.
There is a bit to it than just mounting the Commando engine in a Featherbed, crank balance factor and engine mounts, but I love it its my hotrod Norton and my play bike, but enjoy your Norton and hope you have many long miles a head of you, my Norton is showing its age but that's how I like it just like its owner lol.
Treat your Norton well and pat it on the tank and thank it for a great day out when you get home.

Ashley