Clutch work on my N15CS, some interesting challenges

norton bob said:

The clutch lever i was referring to is inside the box . The Bar lever is important too. 7/8 " pivot to nipple centers needed. 1" is no good, 11/8" even worse .

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Yep got that I just went off on a tangent about the other end.

mdt-son said:

Tom, why don't you fix the root cause? Your oil pump appears to be worn out. Get a new one! Or send the one you have to AMR for an upgrade.

As for your new clutch plates, they can probably be milled down slightly with the correct cutter. Oily clutch plates should be cleaned using a TCE substitution + Fuller's Earth, as described in the Workshop Manual. Oil level in the primary needs to be kept at the bare minimum; lower run of the chain should barely touch the oil surface.

- Knut

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Yes I plan to correct the root cause. I am saving my shekels.

baz said:

After suffering with major clutch slip on my BSA B44 and replacing the friction plates and then replacing the plain plates
Trying an extra plate
Heavy duty clutch springs etc
I hand decked every plate friction and plain both sides until everything was absolutely flat
Plus I tack welded an extra plain plate to the pressure plate and decked that too the clutch was transformed
No more slipping so I could back the tension off the springs which made it lighter to operate
No dragging no slipping and apart from the Norton aluminium pressure plate it's very similar clutch

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I'll get this sorted. I shall endeavor to persevere. I've read through the oil pump rebuild and it's not beyond my skills, just be patient. I think buying a new one would tick me off if it didn't work, or worked for a while, which is what they seem to do anyway. I'd rather have a go at fixing it, and keep about 3 mitigation plans up my sleeve anyway. I will see if I can get it right and if not, OK fine. I have plenty of oil pressure with this pump, am not gonna blow the motor. Just the damn sumpin sumpin. I have it apart and it looks decent, nothing scary going on. After a complete rebuild I am chuffed to find so many things RIGHT with its bike so I won't let this get me down. My timing and primary chain tensions and overall condition of the engine looks great. Charging system, ignition, brakes (re-laced disc on front) power, carburetion spot on, etc. Gotta look on the bright side.

As for clutch plates, I have cleaned off my original oil-soaked ones once already. It worked fine but got contaminated later, my fault. All my clutch springs are in spec. I can put one or two old plates in or deck the new ones, or both. I basically took the original plates, cleaned them, threw them on and they were great, if a bit of a Kung Fu grip, till oil spoiled the party. From the first ride away I was shocked that they even worked. I wanted to test other major systems first and incrementally improve later - which is now.

Oh. Gonna look at the cable at both ends but that is tangential.

Going through my parts pile i found some nice aluminum Barnett plates and a bunch of SS discs - Commando stuff I don't need. They look pretty good and if anyone wants them let me know.

Update: Spoken for already by a fellow alumnus in good standing.

I have had a try at freshening up the oil pump, this pic is in the 'nearly done' stage. I did just a bit more on the end plate to remove the gear mark on the left side. I have no real reference point, this being my first, but I did my best based on some instructional info I found. It seems in pretty good shape overall, again, I'm no expert but it all appears servicable. Using a straight edge and doing several tests got it to what seems like a very good state. We shall see, shall we not?

I don't want to use this word too strongly, but I sort of hate the idea that an oil pump is the fault/cure of all this nonsense. I'll fit it back up and have a good look at the results, mitigating things by checking the seals, then after it's all back together,. I will keep it more upright, drain the sump and measure to see if the pump 'fix' worked etc. I know that the pump cranked out great pressure so that should only get better, I should guess. I want to work on the centerstand too, I had a go at it before but things were just wrong. I don't give up easily though.

There is a post in the Commando forum about a bad wet sumper. In reply #7 there is a link to a video from Andover Norton about how to do exactly what you are doing with the oil pump. At or near the end of the video the Andover Norton engineer in the video says the pump will still wet sump, and nothing can be done about it. Him I believe.

I did the ball bearing and spring in the timing cover in the 1980's. It didn't work more than 7 weeks before the sump had more oil in it than it should. More than 1/2 liter and building. Back then I drained the sump before every ride. I actually thought I'd removed that ball bearing at some point, but 27 years later after a long parking in the corner of the garage. I took the timing cover off and the ball bearing fell out. lol

Schwany said:

There is a post in the Commando forum about a bad wet sumper. In reply #7 there is a link to a video from Andover Norton about how to do exactly what you are doing with the oil pump. At or near the end of the video the Andover Norton engineer in the video says the pump will still wet sump, and nothing can be done about it. Him I believe.

I did the ball bearing and spring in the timing cover in the 1980's. It didn't work more than 7 weeks before the sump had more oil in it than it should. More than 1/2 liter and building. Back then I drained the sump before every ride. I actually thought I'd removed that ball bearing at some point, but 27 years later after a long parking in the corner of the garage. I took the timing cover off and the ball bearing fell out. lol

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Thanks, yes I watched that video. That plus the other guidance I've reviewed cover the process pretty well. Maybe mounting the oil tank under the engine is the only solution

Seems if it's gonna sump and do the leak I may want to drain it after the ride not before, when it cools off anyway. We shall see if my work on the pump did anything.

I will have it back together today with some fixes to the chain case position, moving it closer to the engine by removing 1.2mm of gasket and using Hondabond. sealed the 3 screws. Why on earth Norton tapped the holes through to the crankcase... oh never mind. New clutch cable with adjustment set correctly, re-use of two older plates is just right, dimensionally in the basket. I replaced the crank end seal for good measure while the sprocket was off. I'll use the Type F and I believe it will all be good, and manageable.

Well, oil's well that ends well I suppose. I rode 2 hours through local canyons and 2 lanes with my son on his Tenere 700 yesterday and had another ride today. He insisted on going 75 for long stretches due to light traffic, and so I did too, and even passed him a couple of times at 85. I'm thankful that my gearing is tall....maybe too tall. The clutch doesn't slip at all. There were a couple of drips of ATF under the bike after the ride, but after cinching up the screws a little, it stopped. The new primary chain case gasket may absorb a bit and need a 2nd cinching, my guess anyway. I try not to over-torque steel bolts in alloy threads.

The oil in the tank (15W-40 Rotella T4 which I get because it is fine for wet clutch in my other bikes) has not dropped at all after the ride and sitting. I am hopeful. It was sumping quite rapidly before. I would get about 1.5 liters out of the sump after 5-7 days and the tank would empty in 2 weeks.

This is a nice sight. My cookie sheet clean as a whistle in the morning.

I can't remember how many times I thought my Norton didn't leak anymore. The fantasy never lasted more than a couple of weeks.

Give it some time. It'll mark its territory eventually.

Run your finger under the primary cover seam.

Schwany said:

I can't remember how many times I thought my Norton didn't leak anymore. The fantasy never lasted more than a couple of weeks.

Give it some time. It'll mark its territory eventually.

Run your finger under the primary cover seam.

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Oh for sure, I know it will leak, just happy to have slowed it a bit.

RGM supply two thicknesses of friction plates, 3.5mm and 4.5mm. I had the same issue and the 3.5mm plates fit in clear. Part number 82M11