850 Commando sitting for 9 yrs

Hi all!
New to the forum and new to Norton ownership... I recently purchased a '74 850 Commando with, according to the odometer, 4100 and change miles on it . It looks to be mostly original and is in excellent condition... the guy I bought it off of had the foresight to drain the tank... the bike belonged to his brother who passed in 2015 so it hasn't run since then . So, my question is this , what should my protocol be to starting it ? Change all the fluids , top up the battery , clean the tank somehow , and the Amals? I don't believe it has a Boyer or Pazon which I intend to fit, any thoughts on one or another? I am a fair back yard mechanic and not afraid to wrench but my previous experience with vintage British bikes wasn't great ... I had a '67 Triumph Daytona that I never could get to run right so I sold it and all my WW wrenches vowing never to return, haha. but then I saw this Norton and here I am buying Whitworth wrenches again... Thanks in advance, any input will be greatly appreciated!

Hammerswinger said:

but then I saw this Norton and here I am buying Whitworth wrenches again...

Click to expand...

Many threads/fasteners are Unified so you don't need too many Whitworth tools.

Hammerswinger, Welcome to the forum.
Get the Shop manual. You will find the electronic copy in the Technical Information section at the top of this Commando Forum section.


I would drop the float bowls and check for scale, assuming you have twin carb setup . Drain the oil and primary. Volumes will be in the S/M. New battery would be in order. They don't last uncharged for years on. Its, positive earth or ground on these old bikes unless the P.O. modified it.
Check the timing cover to see what you have and use it to start the bike. Most of this can be done with out the WW wrenches while you wait for them. Go from there.
Cheers,
Tom

Hammerswinger said:

Hi all!
New to the forum and new to Norton ownership... I recently purchased a '74 850 Commando with, according to the odometer, 4100 and change miles on it . It looks to be mostly original and is in excellent condition... the guy I bought it off of had the foresight to drain the tank... the bike belonged to his brother who passed in 2015 so it hasn't run since then . So, my question is this , what should my protocol be to starting it ? Change all the fluids , top up the battery , clean the tank somehow , and the Amals? I don't believe it has a Boyer or Pazon which I intend to fit, any thoughts on one or another? I am a fair back yard mechanic and not afraid to wrench but my previous experience with vintage British bikes wasn't great ... I had a '67 Triumph Daytona that I never could get to run right so I sold it and all my WW wrenches vowing never to return, haha. but then I saw this Norton and here I am buying Whitworth wrenches again... Thanks in advance, any input will be greatly appreciated!

Click to expand...

Welcome.

I would suggest to put a bit of oil into each cylinder and kick the engine over a few times
with ignition off and spark plugs not in and then let it sit for a few days to let the oil run down to the piston rings...

As for quantity of oil, perhaps 20 mls. You don't want to put in so much that you get hydraulic lock when
you crank it with spark plugs in.

Make sure it has a decent fuel filter as there may be some particles coming down from the tank.

I suggest to flush the brake fluid and put in new fluid

If you do try start it with the points still in, don't touch them other to get a small file between them and clean them as there might be a film of corrosion on them meaning no spark. It would be an idea to check for spark before you really try to start it by kicking it over with fresh battery and plugs out, no fuel in tank and each plug with high tension lead attached, and each plug touching ground. My suggestion would be to get it running on the points before you install Boyer or similar. Too many variables.

Also an idea to see that the clutch driven plates are free when clutch is pulled. Thus ignition off, bike in gear, pull in clutch and see if bike will roll when pushed.

Dennis.
Bought my 1973 about a year ago

For the carbs, gotta take them down completely and test if the tiny pilot jet holescare free and clear when spraying cleaner up the air acrew holes. The jets sit in the floor of carb throat, one either aide of where the throttle slide conntacts the floor. Gettingvtgese to work is always a challenge. See an excellent article "Bushmans guide to amal tuning" findable on this site or general google.

The more you do BEFORE you start it the less you will have to repair after you do. To do it 'right' you have to do a lot
but it will have a big return in the long run.
Take the petrol tank off and slosh it out several times. If you have rust in there, deal with it now not later. Phosphoric acid
works but mask the exterior paint well.
If it sat, all the fines will settle and stick to the surfaces of the timing cover, primary and crankcase interior. Take them off and clean. Do the big sump plug filter bit. You will have to go into the timing cover anyway to check the little chain. Might not hurt to put in a new oil pump seal too.
Need I mention the layshaft ball bearing?
Great thing about Commandos is that almost everything is available new.

A 1974 850 with so few miles in original shape is a brilliant find. Many consider it the best model.

But realistically if you want to use a bike of that age which has sat around alot yiou will need to do a fair bit of service type work.

First off the tyres and tubes are probably history.

Starting with the suspension. Drain and replace the front fork flyids. If you get rusty water out of them you may need to dismantle them but otherwise renew the oil.

The rear shocks may have no dampening left. Depending on type you may be able to get them serviced.

Tank has to come off and be flushed as described above. While it's off check over the wiring for cracked or damaged insulation. There should be a 5 wire connector under the tank which is famous for basically falling to bits with age. If your good with wiring I'd go through the lot with a multimeter checking for poor connections. Especially the main switch, the handle bar switches and the kill button if connected. My bike sat in good conditions for 5 years and I found about 4 bad connections from memory. The new battery is a good recommendation. You have options on the ignition and I'd go with whatever you feel OK with. I use Pazon but that's as much that Andy lives in NZ and responds in a few hours whenever we have issues. ( ignitions used on race bikes) . New plugs probably and maybe new HT leads.

Drain all the fluids including primary. New oil filter and I'd probably wash out the oil tank too. It will give you a heads up if there is any motor issues. Check the oil pipes carefully. After this time they may be cracked or perished. Personally I'd probably instal new ones.

Oil down the barrels is probably a good idea. BUT DO NOT TURN THE ENGINE OVER UNTIL YOU HAVE REMOVED THE TAPPET COVERS AND POURED SOME OIL DOWN THE PUSHROD TUNNELS TO LUBE THE CAMS AND FOLLOWERS. While your in there check the tappet clearance.

The suggestion about replacing the layshaft bearing is a good one. This is a necessary upgrade and a safety issue.

I'd also pull the clutch and clean it because it's probably stuck together by now. This also gives you a chance to check the wires from the stator through the hole at the back of the primary case. They often wear and break at that point.

Carbs. Definitely totally clean. Ultrasonic bath if possible. The mixing chamber under the pressed in brass plug is almost certainly blocked. Someone recomended the Bushman's notes I think. Good suggestion.

Brakes. I'd replace the seals in the calliper and master cylinder. The linings on the rear shoes can delaminate if left for years. I know. It happened to me so new brake linings or shoes may be in order.

Whatelse. Obviously go over the bike with and oil rag and check for corrosion, lube all the cables and levers. The isolastics will probably need adjusting. And the chains. Swinging arm will need oil. 140 wt.

OK. So that's off the top of my head based on a referb I did on my 850 after some years in storage.

There lots of good ideas above as well.

Theres a lot of experienced owners around. What part of the country are you located in?

johnm said:

A 1974 850 with so few miles in original shape is a brilliant find. Many consider it the best model.

But realistically if you want to use a bike of that age which has sat around alot yiou will need to do a fair bit of service type work.

First off the tyres and tubes are probably history.

Starting with the suspension. Drain and replace the front fork flyids. If you get rusty water out of them you may need to dismantle them but otherwise renew the oil.

The rear shocks may have no dampening left. Depending on type you may be able to get them serviced.

Tank has to come off and be flushed as described above. While it's off check over the wiring for cracked or damaged insulation. There should be a 5 wire connector under the tank which is famous for basically falling to bits with age. If your good with wiring I'd go through the lot with a multimeter checking for poor connections. Especially the main switch, the handle bar switches and the kill button if connected. My bike sat in good conditions for 5 years and I found about 4 bad connections from memory. The new battery is a good recommendation. You have options on the ignition and I'd go with whatever you feel OK with. I use Pazon but that's as much that Andy lives in NZ and responds in a few hours whenever we have issues. ( ignitions used on race bikes) . New plugs probably and maybe new HT leads.

Drain all the fluids including primary. New oil filter and I'd probably wash out the oil tank too. It will give you a heads up if there is any motor issues. Check the oil pipes carefully. After this time they may be cracked or perished. Personally I'd probably instal new ones.

Oil down the barrels is probably a good idea. BUT DO NOT TURN THE ENGINE OVER UNTIL YOU HAVE REMOVED THE TAPPET COVERS AND POURED SOME OIL DOWN THE PUSHROD TUNNELS TO LUBE THE CAMS AND FOLLOWERS. While your in there check the tappet clearance.

The suggestion about replacing the layshaft bearing is a good one. This is a necessary upgrade and a safety issue.

I'd also pull the clutch and clean it because it's probably stuck together by now. This also gives you a chance to check the wires from the stator through the hole at the back of the primary case. They often wear and break at that point.

Carbs. Definitely totally clean. Ultrasonic bath if possible. The mixing chamber under the pressed in brass plug is almost certainly blocked. Someone recomended the Bushman's notes I think. Good suggestion.

Brakes. I'd replace the seals in the calliper and master cylinder. The linings on the rear shoes can delaminate if left for years. I know. It happened to me so new brake linings or shoes may be in order.

Whatelse. Obviously go over the bike with and oil rag and check for corrosion, lube all the cables and levers. The isolastics will probably need adjusting. And the chains. Swinging arm will need oil. 140 wt.

OK. So that's off the top of my head based on a referb I did on my 850 after some years in storage.

There lots of good ideas above as well.

Click to expand...

Many good points made here
Plus the ones above it
And as stated,use 140 wt oil do not pump grease into the grease nipple on the swinging arm pivot
Don't forget the choke works with slack wire on
Tight wire off

When you get ready to check for spark, if none, then look at the kill switch. Mine was ugly corroded.
jaydee

One way to consider your Norton is how fast are you prepared to ride it without a thorough going over?
Its been dead in the water for 9 years...find any mice nests?
It doesn't take much for things to go sideways, mechanically and/or on the road.
Play it safe, there is no downside from that perspective.

Bet you're glad you asked!

+ makes sure everything's tight and check the tappet clearances after tightening the head. I find a good slow bike clean tells me a lot, what's leaking, corroded, bent, worn and even loose. I just got back from 50 miles on my 850. Don't want to jinx it, but the 1st 3 months were problems. Plenty of help from this bunch, then 3 years of faultless fun. Favourite bike.

Welcome! All good advice above. I tend to keep things simple (KISS). Clean carbs drain oil, change all filters. Now is where I differ from some others! When refilling oil, as best you can fill filter before install. Fill oil tank full, leave it sit a day to allow air to naturlly bleed from oil lines. Remove spark plugs and kick it over until you see oil returning to oil tank, small tube close to the filler cap. Have heard of people starting a stored or rebuilt engine and not seeing oil return for "minutes" which scares the shit out of me. Good luck do the repairs as needed. Enjoy owning a classic

Mart UK said:

Bet you're glad you asked!

+ makes sure everything's tight and check the tappet clearances after tightening the head. I find a good slow bike clean tells me a lot, what's leaking, corroded, bent, worn and even loose. I just got back from 50 miles on my 850. Don't want to jinx it, but the 1st 3 months were problems. Plenty of help from this bunch, then 3 years of faultless fun. Favourite bike.

Click to expand...

Even more favourite than that Softail Slim hiding behind the Nort ??

Welcome... Drain the engine oil from the crankcase as the contents of the oil tank will be in there..
Change the oil at this point wouldn't be a bad call

If the tank is rusty you can fill with white vinegar and let it sit for a few days to a week it won’t damage the paint. Once it’s clean of rust give it a good spray with WD40 to keep the rust at bay until needed.

Fast Eddie said:

Even more favourite than that Softail Slim hiding behind the Nort ??

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Long gone. Lasted 6 months. Sold before I wore the lower frame rails away. Good in a straight line only. Don't know what I was thinking, mid-life crisis

L.A.B. said:

Many threads/fasteners are Unified so you don't need too many Whitworth tools.

Click to expand...

Thanx, good to know!

CanukNortonNut said:

Hammerswinger, Welcome to the forum.
Get the Shop manual. You will find the electronic copy in the Technical Information section at the top of this Commando Forum section.

http://www.classicbike.biz/Norton/Repair/70up_Commando/70upCommando.pdf

http://www.classicbike.biz/Norton/OwnersManuals/70s/73Commando-OwnerMan.pdf

I would drop the float bowls and check for scale, assuming you have twin carb setup . Drain the oil and primary. Volumes will be in the S/M. New battery would be in order. They don't last uncharged for years on. Its, positive earth or ground on these old bikes unless the P.O. modified it.
Check the timing cover to see what you have and use it to start the bike. Most of this can be done with out the WW wrenches while you wait for them. Go from there.
Cheers,
Tom

Click to expand...

Thank you for all the great input, and the welcome!