850 MK II Commando Reliability?

phippsy said:

Fit LEDs all round and fit a tri-spark mosfet rectifier no more problems with your ignition ,and then enjoy your roadster ,remembering the blue ones are the best ones !

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46 years of ownership and most of its life was a everyday rider the only time it let me down was a broken chain and a blown Boyar black box but it wasn't the Boyar fault, as well the dreaded lay shaft bearing back in 79 lucky it blew when outside in front of my house when I put it in gear, I converted my 74 850 to the Featherbed frame back in the early 80s and made the wiring simple with engine rebuild for the Featherbed and a few good things done to the motor, the bike has been reliable ever since and have clocked well over 160k miles on it, have done lots of long distant travels as for 15 years was my only transport, the biggest thing to do is run good oil and do all the maintenance when needed and I mean everything not just a oil change, these are very reliable bikes if things are done right and will give you trouble free riding, yes things do need replacing or fixing over time but its all part of maintenance.
I now run full Grimica front brakes up front, a Joe Hunt maggie, Lansdown inturnals in the front end and have always had Koni shocks on the back, been on the bike since 1978, my motor isn't stock and has a bit of work inside but still very reliable, as for wet sumping just ride the bike regularly don't let it sit and you won't have no troubles with wet sumping, mine only wet sumps if I let it sit for a few months as my Norton has been semi retired now for 7 years as I have 2 other modern Triumph Thruxtons but I still love taking the Norton out and always fires up on first kick everytime.
Anyway good luck with your new ride and just enjoy it, do the maintenance and fix things when needed as its all part of owning anything, not just a Norton.
Ashley

I'm envious of your Fireflake Blue Commando.

One mod I would recommend is a reed valve breather.
This being one of the best.

With this breather, I don't care about sumping.
Simply push the kicker through a couple times to clear some crank space, then fire it up.
Oil cycles back into the tank, along with all the benefits of a reed breather.
Works Great!!!

MichaelB said:

I'm envious of your Fireflake Blue Commando.

One mod I would recommend is a reed valve breather.
This being one of the best.

Reed Breather Kit

The Norton twin cylinder engine creates a serious amount of pressure in the crankcase as the motor spins. Over the years the factory attempted several methods to reduce this pressure – from a timed breather off the end of the cam on earlier motors, to a crude straight pipe from the timing chest on

nycnorton.com

With this breather, I don't care about sumping.
Simply push the kicker through a couple times to clear some crank space, then fire it up.
Oil cycles back into the tank, along with all the benefits of a reed breather.
Works Great!!!

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Now that has my interest. Why not create some negative or at least neutral crankcase pressure as you scavenge the case? Might be good for some HP to boot! How hard is it to install with the engine in the frame? Works similar to turning an aircraft radial engine backward to scavenge the oil out of the bottom cylinders.

To be honest, the fireflake blue is a respray albeit a really well done respray.

Dan1950 said:

Now that has my interest. Why not create some negative or at least neutral crankcase pressure as you scavenge the case? Might be good for some HP to boot! How hard is it to install with the engine in the frame? Works similar to turning an aircraft radial engine backward to scavenge the oil out of the bottom cylinders.

To be honest, the fireflake blue is a respray albeit a really well done respray.

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The breather shown, from nyc, literally just replaces the existing sump plug and requires a new hose to the oil tank.

Some care is required to ensure it is aligned as you require it so the outlet for the hose iis in the desired place. You have to fit it tight to see if the outlet needs moving. If so, mark it and remove it, dismantle it and move the outlet to the desired position, re assemble and fit.

Worst case scenario is you might have to file / linish a chamfer on the leading edge of the tube that protrudes into the cases.

Its really not difficult to do, especially if you have the bike on the ramp / in the shed doing other recommissioning work at the same time and your brain is in that gear.

I‘ve used one since 2014.

I tend to look at "upgrades" to 'fix' a problem with this question: "Was this [problem] an issue when these bikes were new?" If the answer is "no," then the fix isn't adding 'upgrade' parts. It's simply ensuring that the bike works as it did when 'new.'

Dan1950 said:

The description says TMU, 8155 indicated. Besides, the bike is 47 years old.. If the harness insulation is still supple, I'll leave well enough alone. If it is stiff or brittle, I'll re-wire it. (Winter project)

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At a minimum I would replace all the double female bullet connectors. The metal internals are very fragile and prone to breaking. Cheap and would be a very quick job and may save a bit of roadside troubleshooting.

Theses are hard to find on the site - http://www.britishwiring.com/C-336-p/c336.htm

Fast Eddie said:

It’s only done 8,000 miles !

If it were me I’d go through the wiring, check all connections etc, perhaps apply dielectric grease to all connectors, replace any perished rubber female bullets etc. But I wouldn’t be re wiring it !

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I agree. I have a '74 850 and found the wiring and bullets and almost all connectors to be in very good shape. The large 10-way connector under the front of the tank was toast so I replaced that. I would definitly inspect, grease the connections, and replace any problems. But based on my experience, you wont find many.

Dan,
I would switch to a MOSFET regulator-rectifier.Read up on them to see why.
Mike

If not already fitted, a brake pedal return spring should be high on your list of upgrades. Without it If the cable happens to snap the pedal will drop to the road with potentially dire consequences.

cliffa said:

If not already fitted, a brake pedal return spring should be high on your list of upgrades. Without it If the cable happens to snap the pedal will drop to the road with potentially dire consequences.

Motorcycle parts and spares for Norton motorbikes - Genuine Andover Norton Spare Parts - Andover Norton Motorcycles Parts - Original Andover Norton Parts

Motorcycle parts and spares for Andover Norton motorbikes: Andover Norton manufactures and supplies all Genuine Factory Spare Parts for Norton motorcycles built before 2002.

andover-norton.co.uk

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Yes I saw that mentioned on a "The Mighty Garage" video.

cliffa said:

If not already fitted, a brake pedal return spring should be high on your list of upgrades. Without it If the cable happens to snap the pedal will drop to the road with potentially dire consequences.

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And if you're using the OEM rear brake switch, the spring also helps the brake lever return to its full stop which insures that the switch turns off. Before I added the spring I was in the habit of lifting the brake lever with my toe to be sure the switch turned off.

All good info....
Without the crankcase breather on an 850 you're likely to have excess pressure in your oil tank and if you fill your oil tank full, it will puke the excess into your air filter. That will drip downward in front of the rear tire :-(

Of course, don't fill oil tank until the crankcase has voided the wet sumping after startup. Kind of the same for the primary, if overfilled, the felt seal around the trans output won't be able to withstand the onslaught. I just put the recommended amount of oil in the forks and primary. No doubt you're read not to grease the swing arm spindle even though there is a zerk fitting. The seals don't unless there's been recent renewal there and it's been 47 years gone by otherwise.

MichaelB said:

I'm envious of your Fireflake Blue Commando.

One mod I would recommend is a reed valve breather.
This being one of the best.

Reed Breather Kit

The Norton twin cylinder engine creates a serious amount of pressure in the crankcase as the motor spins. Over the years the factory attempted several methods to reduce this pressure – from a timed breather off the end of the cam on earlier motors, to a crude straight pipe from the timing chest on

nycnorton.com

With this breather, I don't care about sumping.
Simply push the kicker through a couple times to clear some crank space, then fire it up.
Oil cycles back into the tank, along with all the benefits of a reed breather.
Works Great!!!

Click to expand...

Michael,

I have an in-line reed valve on my 850 mk 2a on the original breather from the back of the timing chest and I also have a tap with a switch on the oil feed to stop sumping, I’m not overly happy having a tap on the oil feed even with an ignition cutout. Am I right in thinking the Comstock/NYC sump mounted breather will clear the sump by kicking through a few times or am I misunderstanding? If my interpretation is correct then this seems an ideal solution providing both a reed valve breather and a means of clearing the sump.

Dave

Dellis said:

Am I right in thinking the Comstock/NYC sump mounted breather will clear the sump by kicking through a few times or am I misunderstanding? If my interpretation is correct then this seems an ideal solution providing both a reed valve breather and a means of clearing the sump.

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That is basically correct.

The only caveat being, it depends just how full the sump is…!

The cNw type, mounted in the ‘Combat’ location, also does the same.

If the sump is REALLY full then the kicker will not want to move. By standing on it, it
will pressurize the cases and you will hear the flapper make some noise as the oil
is forced up the hose and into the tank. Remember I am rather light weight so a normal
sized person might force the issue a bit too much. Don't want to damage anything.

Dellis said:

Michael,

I have an in-line reed valve on my 850 mk 2a on the original breather from the back of the timing chest and I also have a tap with a switch on the oil feed to stop sumping, I’m not overly happy having a tap on the oil feed even with an ignition cutout. Am I right in thinking the Comstock/NYC sump mounted breather will clear the sump by kicking through a few times or am I misunderstanding? If my interpretation is correct then this seems an ideal solution providing both a reed valve breather and a means of clearing the sump.

Dave

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Yes, that is correct. And yes, it works well.
I too, feel it is ideal.

Fast Eddie said:

That is basically correct.

The only caveat being, it depends just how full the sump is…!

The cNw type, mounted in the ‘Combat’ location, also does the same.

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I've never had a sump so full I couldn't cycle through.
I guess anything is possible.
Actually, those with 'Combat' or factory rear breathers can cycle the same way, with or with out the reed valve breather.

The thing that bothers me about a sump breather setup is when my bike has wet sumped, I can see the oil feed sieve exposed in bottom of tank. That means there is no oil down the feed pipe into the pump. So even if the sump breather returns oil to tank in short order, there is little to no oil feed happening for some period of time at start up. I guess you can try pre-kicking a few dozen times until you see the feed sieve is submerged again.

MichaelB said:

Actually, those with 'Combat' or factory rear breathers can cycle the same way, with or with out the reed valve breather.

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Not quite me thinks, without the one way effect of the reed valve, the oil which be filling the breather pipe back to the tank, will be sucked back in each revolution, severely reducing the effectiveness of emptying the sump of oil.

Fast Eddie said:

Not quite me thinks, without the one way effect of the reed valve, the oil which be filling the breather pipe back to the tank, will be sucked back in each revolution, severely reducing the effectiveness of emptying the sump of oil.

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Good point Eddie.
Once started, it will clear the sump through the breather. But clearing could be an issue.
I got in the habit years ago before the reed valves of cycling the crank to make sure the engine wasn’t hydraulic’d. If it was too stiff. I would drain.
With the reed, you feel it loosen up.