Newbie help please!

Zep1975 · Jul 22, 2018

Hi all. Thanks for accepting me into the group.
Following a chance remark on the Norton Facebook page I recently fulfilled a long held ambition to own a 1975 Mk3 Commando.
The bike was a none runner but following, amongst other things, a rewire, new Wassell ignition and some carb fettling, including new slides, I finally got it running well.
Unfortunately following a couple of runs I started to notice oil leaks from the head gasket. It turned out that one of the front 5/16 studs had stripped the thread in the head and the two front 3/8 studs are starting to pull out.
I've now managed to remove the head, what a pain that was, to deal with the issues.
I now have a couple of questions.
First off I plan to have thread repair inserts fitted into all three stud holes in the head as well as the two in the barrel. Would you say that is advisable even though only three of them have actually stripped?
There were no problems with any of the five head to barrel bolts. Are there any known issues with these?
The composite head gasket was in a terrible state. I intend replacing it with another composite one, mainly because I've had the best results with this type on my Triumph and BSA triples, but wondered if there is a preferred supplier in order to source the best one out there?
Any tips on using or not using sealants with the gasket and the torquing procedure would be welcomed. Also are new head bolts advisable and how do you get a torque wrench on the three nuts that are tightened from below?

Does anyone know of a supplier, preferably a Norton specialist, who may be able to carry out the repairs to the head and barrel as well as check for flatness? I'm in North West England but wouldn't mind posting them out anywhere in the UK.

One other issue I have is an oil leak that seems to be coming from above the oil pipes on the side of the oil tank. Up to now I can't seem to find the source of the leak and wondered if there are any known issues in this area which may point me in the right direction.
Thanks in advance for any help you can give.
Peter

N0rt0nelectr@ · Jul 22, 2018

If you were in the US I would recommend Jim Comstock in Pueblo Colorado.
Who ever you use get them all done and take a long hard look at the exhaust port threads too.

John in Texas

frankdamp · Jul 22, 2018

Unfortunately. I can't recommend anyone, even though I'm originally from Leyland. I've been in the western US since emigrating in 1968, after 18 months or so at N-V's Wolverhampton development center at the Villiers works there. Things have changed substantially since then.

Sorry to hear about your problems.

brokeneagle · Jul 22, 2018

The oil tanks are prone to crack where the bolt goes up into the bottom. Check there.

oldmikew · Jul 22, 2018

Mike Pemberton - he specialises in singles but has also worked on Twins... he advertises in Roadholder the Norton owners club comic and big plus -is in your neck of the woods... There is an engineering outfit that posts on youtube .you would have to have a trawl . They also seem very good .. and finally Norman White who has a web site

gortnipper · Jul 22, 2018

https://www.accessnorton.com/NortonCommando/oil-tank-mod-apologies-to-cnw.7348/

Onder · Jul 22, 2018

I have the CNW oil tank mod...no problems so far. Make sure the rubber mounts are new and soft.
Have you inquired with RGM for head work or possibly SRM? It will cost to ship to USA but Jim Comstock
will sort you without worry.

Jerry Doe · Jul 22, 2018

FD motorcycles. They are in essex. Call nick or Andy. I went to school with them. Been building commandos since then. They can easily do this. Cheers

https://www.fdmotorcycles.co.uk/

Towner · Jul 23, 2018

Hi,

the best parts supplier in UK is Andover Norton. Why don't you call them for a recommandation of a good workshop.
https://andover-norton.co.uk/

Ralf

Onder · Jul 23, 2018

I knew they did paint somehow missed the fact they did shop work as well.
Another reason this site is so valuable. Imagine this in 1980!

SteveBorland · Jul 23, 2018

For parts, try RGM or Andover. RGM actually supply the Andover composite gasket, and it seems to work fine.

Regarding head bolts, I bought a set from cNw which are machined down in the center to allow more stretch. Somewhat expensive, but they work very well. After I lifted the head last time, I've retorqued twice, with no apparent change in the tightness. The standard bolts keep on requiring tightning again and again. Comnoz here on the forum does these bolts for cNw. Read the thread here: https://www.accessnorton.com/NortonCommando/oil-leak-at-the-head-gasket.21483/

It's not realluy practical to get a torque wrench on all the fastners, so just use your common sense and feel on the inaccessable ones. Some people have cobbled together a collection of crows feet and things though, again ,a search should find the info.

Cheers,
Steve.

Fast Eddie · Jul 23, 2018

RGM and FD are good suggestions. I think Norman White and Mick Hemmings are also still doing engine work.

As Steve says, the stock composite gasket is perfectly fine provided surfaces are good. The cNw bolt kit also has the HUGE advantage of allowing the use a good sockets that allow use of the torque wrench etc, rather than the rag-tag collection of home made tools and box spanner’s and lengths of wood etc required by the stock set up!

SteveBorland · Jul 24, 2018

Hmm, while I really like the set, I'm not convinced of the superiority of the 12 point heads. I found it very frustrating trying to get the one just over the tacho drive started on the thread - with the standard hex head, you can hold it in place with a finger and turn it with a spanner to get it to start. With the 12 point, you have to bugger about with a ring spanner... The kit does have the advantage of only using 2 socket sizes though, I grant you.

kommando · Jul 24, 2018

RGM are in Cumbria so closest to NW England.

Chucktri · Jul 25, 2018

Zep1975 said:
Hi all. Thanks for accepting me into the group.
Following a chance remark on the Norton Facebook page I recently fulfilled a long held ambition to own a 1975 Mk3 Commando.
The bike was a none runner but following, amongst other things, a rewire, new Wassell ignition and some carb fettling, including new slides, I finally got it running well.
Unfortunately following a couple of runs I started to notice oil leaks from the head gasket. It turned out that one of the front 5/16 studs had stripped the thread in the head and the two front 3/8 studs are starting to pull out.
I've now managed to remove the head, what a pain that was, to deal with the issues.
I now have a couple of questions.
First off I plan to have thread repair inserts fitted into all three stud holes in the head as well as the two in the barrel. Would you say that is advisable even though only three of them have actually stripped?
There were no problems with any of the five head to barrel bolts. Are there any known issues with these?
The composite head gasket was in a terrible state. I intend replacing it with another composite one, mainly because I've had the best results with this type on my Triumph and BSA triples, but wondered if there is a preferred supplier in order to source the best one out there?
Any tips on using or not using sealants with the gasket and the torquing procedure would be welcomed. Also are new head bolts advisable and how do you get a torque wrench on the three nuts that are tightened from below?

Does anyone know of a supplier, preferably a Norton specialist, who may be able to carry out the repairs to the head and barrel as well as check for flatness? I'm in North West England but wouldn't mind posting them out anywhere in the UK.

One other issue I have is an oil leak that seems to be coming from above the oil pipes on the side of the oil tank. Up to now I can't seem to find the source of the leak and wondered if there are any known issues in this area which may point me in the right direction.
Thanks in advance for any help you can give.
Peter

Peter,
I haven't logged in for ages, so I don't know if you've found someone to do the work on the head. I would highly recommend you look up a nearby chapter of Norton Owners Club. They would be the best source for Norton specialists in the UK.

Chuck

Zep1975 · Jul 26, 2018

Thanks all for the very helpful replies and information so far.

Further inspection of the head and barrels has shown that the two front 3/8 studs already have inserts fitted. It is the inserts that are pulling out. The retard who carried out the work then used studs that only threaded half way into the the hole. Hence them pulling out.

Of the two 5/16 studs one has a stripped thread and one has a BSF insert fitted. Both studs are wrong anyway.

I really like the sound of the CnW head and barrel assembly kit but with shipping and tax it would work out very expensive. Are there any UK suppliers for these parts?

One piece of good news is that the Headshop in Warrington can do the repairs for me. I've used him quite often in the past and have been happy with his work. Turnaround can be a bit lengthy but I'v got plenty of other projects that need work so it shouldn't be a problem.

Part

Newbie help please!

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