Mystery Hole in P-11 inner primary cover

MikeInMass · Aug 31, 2023

Hello again. We have another member with a newly acquired Norton P-11 . He has started cleaning and inspecting it, and has a question about a hole
in the inner primary cover. The hole is to the immediate right of the hole where the alternator wires come through, and above the big stud which I
suspect the outer cover is attached to.
Once again, any info appreciated. I'm wondering if there was ever a service manual written specifically for the P-11 and/or Atlas style Nortons, and better yet,
a parts manual ?
Thanks again !

Schwany · Aug 31, 2023

Welcome to the undocumented world of the P11.

There is a White Master Parts List manual and a Red Maintenace and Instruction Manual, but nothing like the documentation that Commando owners have available. Andover Norton carries the documents. Baxters, British Cycle Supply, and others in the states probably carry docs. I used Haynes manuals when I put mine together. They still come in handy but have nothing useful about the unusual parts used on a P11 in them.

There are quite a few exploded diagrams showing parts on the Andover Norton website in the Desert Sleds section. The gearbox shell is unique as is the frame and neither can be purchased new.

The hole:

I run my wiring for the stator through that hole and plug the little one typically used for the stator wires. I'm not sure what that hole is really for on the P11, but you should plug it if not used. Oil will find its way out of the primary.

Ron L has restored a lot of P11's. He may know what that hole is actually for. Securing the inner case on an N15 is my guess? The N15 which also uses that Matchless style primary does not use the hole below that one for the foot peg and the outer primary does not have a hole in it for the foot peg.

Ron L · Aug 31, 2023

Looking at a number of restored, complete, and nearly complete P11's and Ranger 750's of mine and a buddy of mine, I have never seen any use that hole . I suppose it could have been intended as a vent and I have seen photos of P11's that have been tapped and fitted with a piece of copper tube to route a a hose away to keep oil leak to a minimum. I usually fit a rubber plug to the opening as there is usually enough air escaping around the transmission shaft to vent the case.

As to the G80/G85/P11 Maintenance and Instruction Manual, it contains minimal information useful to aid in rebuilding a P11. The '67 P11 parts manual is a decent parts list, but no illustrations and you need to understand British motorcycle lingo. The '66-'67-'68 Master Parts list again is useful, but there are several part omissions for P11 and P11A.

gpzkat · Aug 31, 2023

This thread may help if it's the same one as on the N15CS, as Schwany sent a pic that shows it.

https://www.accessnorton.com/Norton...case-support-stud-location.36830/#post-619974

I bought a rubber stopper of the right size, drilled a hole through it and ran a bolt through, tightened it up good and snug with a washer, loctite, and a nut on the back. It's not going anywhere and I won't mist my engine with primary oil.

Junglebiker · Sep 1, 2023

Mine has one hole for the footpeg mount and one hole which is currently blocked with a bolt, a nut and a copper washer. I assumed that the blocked hole was originally for the stator wires and that maybe this primary came off of a race bike fitted with a magneto, which would explain why the hole was blocked. Maybe?

gpzkat · Sep 1, 2023

Junglebiker said:
Mine has one hole for the footpeg mount and one hole which is currently blocked with a bolt, a nut and a copper washer. I assumed that the blocked hole was originally for the stator wires and that maybe this primary came off of a race bike fitted with a magneto, which would explain why the hole was blocked. Maybe?

A magneto will run the ignition but not supply current to the lights. For that, you need the alternator. There's another hole for the alt's wires. At least on mine there is, with a little rubber grommet. It's a 'spare' hole from what my post revealed. Good to plug it up, I say.

MikeInMass · Sep 3, 2023

Schwany said:
Welcome to the undocumented world of the P11.

There is a White Master Parts List manual and a Red Maintenace and Instruction Manual, but nothing like the documentation that Commando owners have available. Andover Norton carries the documents. Baxters, British Cycle Supply, and others in the states probably carry docs. I used Haynes manuals when I put mine together. They still come in handy but have nothing useful about the unusual parts used on a P11 in them.

There are quite a few exploded diagrams showing parts on the Andover Norton website in the Desert Sleds section. The gearbox shell is unique as is the frame and neither can be purchased new.

The hole:

I run my wiring for the stator through that hole and plug the little one typically used for the stator wires. I'm not sure what that hole is really for on the P11, but you should plug it if not used. Oil will find its way out of the primary.

Ron L has restored a lot of P11's. He may know what that hole is actually for. Securing the inner case on an N15 is my guess? The N15 which also uses that Matchless style primary does not use the hole below that one for the foot peg and the outer primary does not have a hole in it for the foot peg.

Thanks for that, Schwany !

MikeInMass · Sep 3, 2023

Thanks for all the info, everyone. I will convey it to our member.

Junglebiker · Sep 3, 2023

Just saw this post on the FB P-11 page--interesting that my primary has only 2 holes (one of which is plugged and the other which has the footpeg bolt through it) but the one in this pic has a third hole drilled where my primary has only a boss with no hole drilled in it. oh and BTW, yes, I do plan to unplug the plugged hole eventually for my stator wires. That will all come after I get it started, which won't be for a couple years yet since I am in Papua New Guinea right now and won't be back in the US for some time.

MikeInMass · Sep 9, 2023

Junglebiker said:
Just saw this post on the FB P-11 page--interesting that my primary has only 2 holes (one of which is plugged and the other which has the footpeg bolt through it) but the one in this pic has a third hole drilled where my primary has only a boss with no hole drilled in it. oh and BTW, yes, I do plan to unplug the plugged hole eventually for my stator wires. That will all come after I get it started, which won't be for a couple years yet since I am in Papua New Guinea right now and won't be back in the US for some time.

Thank you for the picture !

Mystery Hole in P-11 inner primary cover

MikeInMass

Schwany

Ron L

gpzkat

Junglebiker

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MikeInMass

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