Stuck exhaust lock ring right cylinder 750 Norton Commando 1971

Been quite a while since I was here the last time. After cleaning up the electrics , adding a Tri-Spark Ignition, dual output coil from Colorado Norton Works and finally a single Mikuni Vm32, the bike has functioned flawlessly during the last 4 years. That was until recently when my right exhaust pipe suddenly made a distinctive noise, and correctly, the whole circumference of the pipe was basically cut off about 2-3 centimeteres behind the rose of the lock ring. Didn't think this would be a problem, after all the pipes was 50 + years old. A par of new front pipes were orderer from Norton Owners Club. I thought I could stick with the existing lock nut.
The left one came off without any issue, the right one not so. I have tried evererything, PW , heat but it just won't come loose. Just read a thread from Norton Owners Club where I was reading as many theories about how to brake them loos as I think they have members. Heat guns, hammers, youi name it, one theory after
Since I got a lot of extremely good help back in 2010 here at access norton I was hoping somebody could give me a procedure that actually works. The bike is otherwise perfect and I would hate to rip the threads in the head. PS. I have already orderer this BMW tool that supposedly works well since it grips over 8 teeth on the exahaust rose and not only one as the C-clip
Thanks for the attention!!

Kjell said:

I have already orderer this BMW tool that supposedly works well since it grips over 8 teeth on the exahaust rose and not only one as the C-clip

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Apparently the BMW tool doesn't fit all Norton Commando lockrings.

A piece of pipe over the handle for more leverage.
I used a chain link fence post I had laying around.
It actually deformed the post, got it loose..

MichaelB said:

A piece of pipe over the handle for more leverage.
I used a chain link fence post I had laying around.
It actually deformed the post, got it loose..

Click to expand...

Yep , a length of pipe over the tool handle . An old worn out stanchion tube works , I don't toss them but use them as extenders to tools . Exhaust rose nuts and fork seal retainers come to mind . Also torch up the area with a propane torch . you could soak the threads area in penetrant for a day or two first . Pressure with shock .

Another trick is to apply the torque (extended pipe handle as mentioned above) with the bike running.
The heat in the exhaust area plus vibration from the running engine can work wonders! Have a friend vary the revs while you do it.
Cheers

As a last resort I would carefully cut the lock-ring in half with a Dremmel tool or something similar, better to sacrifice an exhaust nut than the thread in the head.

For the toughest stuck stuff I have encountered, I have used heat on the surrounding area (160C or so) to expand, and ice cubes or a can of 'freeze spray' on the inner to 'shrink' it. And several cycles of heat/cool with good penetrating oil or ATF/acetone mix beforehand, giving it some whacks with a steel punch. Good luck!

I use a plumbers monkey wrench with a 6 foot length of steel 1 inch ID black pipe over the handle of the monkey wrench. It will crush the exhaust rose fins a little but it will also turn them off. You might need someone to hold onto the bike when you use a 6 foot long lever to keep the bike from falling over. You could put a few small ball bearings in between the fins where the wrench's jaws are and the wrench would crush the fins a little less than without ball bearins holding the fins apart. I always put copper antisieze on the nut threads now when I put them in. It helps them stay put and come off when I want them to.

Kjell, are you Kjell Jacobson ? In my high school in New York 50 years ago, we had 2 foreign exchange students from Norway, Rune Anderson and Kjell Jacobson. It's a longshot, but I figured I'd ask...

L.A.B. said:

Apparently the BMW tool doesn't fit all Norton Commando lockrings.

Click to expand...

BMW Tool that I ordered has to be extensively modified to fit.

Odd, as most owners struggle to keep these tightened.

Are you sure your bike has RH thread there? Mine had oversized LH threaded exhaust rose nuts from a dreaded previous owner.

Seems the head needs to be hot, like at least operating temperature. Many recommend torquing these up on a hot engine and with it still running to make vibrations help. So removal may need similar.

Lots of heat, very long lever, plus hammer blows to the lever close to the nut whilst max pressure exerted on the lever.
A heat gun won't be enough - needs to be a propane torch at least. If the ex pipe has sheared it should be easier to focus the heat on the inside of the nut and allow conduction to do the rest.

Tornado said:

Odd, as most owners struggle to keep these tightened.

Are you sure your bike has RH thread there? Mine had oversized LH threaded exhaust rose nuts from a dreaded previous owner.

Seems the head needs to be hot, like at least operating temperature. Many recommend torquing these up on a hot engine and with it still running to make vibrations help. So removal may need similar.

Click to expand...

The one on the left cylinder came loose without a problem and that one was normally threaded - anti clockwise to loosen. I am in the process of making a tool that will fit over at least 5-6 fins. I already broke 5 of them trying to use a pipewrench and nothing else. I will mix some aceton and dexron III and soak the threads as far as possible for several days. Long lever on the tool, bring the bike up to normal temp and ice spray the exhaust ring. If that doesnt work the heads has to come off

If you have access to an acetylene and oxygen torch, use a welding tip in it. Heat just the ring, not the head, until it just starts to turn red. doing this in a not bright area will help it to show sooner. After the ring has cooled completely, it should be easier to remove. When the ring is heated, it expands in the cool head. This why a torch is used, so it expands quickly and not let heat soak into the head. Te expansion should slightly crush any carbon, crud or the threads in the head. This little bit of play usually makes it possible to remove the ring, bolt or whatever you are trying to remove. By completely cooled, I mean that you can comfortably rest your hand on it. Steel expands at a rate of 3/4" per 100 feet per 100 degrees, If you want to know how much it will push on the threads.

Kjell said:

The one on the left cylinder came loose without a problem and that one was normally threaded - anti clockwise to loosen. I am in the process of making a tool that will fit over at least 5-6 fins. I already broke 5 of them trying to use a pipewrench and nothing else. I will mix some aceton and dexron III and soak the threads as far as possible for several days. Long lever on the tool, bring the bike up to normal temp and ice spray the exhaust ring. If that doesnt work the heads has to come off

Click to expand...

Perhaps a chain-wrap type "wrench", like are used on big/truck sized oil filters sometimes.

franco - that is very interesting, wow. Good explanation.

Kjell - If you have a chain hoist or come-along, you can lift the front of the bike skyward to get that witches brew to soak downward. I consider a $50 (or so) 1-ton chain hoist indispensable in my garage.

Hopefully, someone didn't do something silly like JB-weld the threads. When you're done and reassembling, I'd recommend these Suzuki exhaust gaskets. I have sorted my bike with them, once installed, they have never loosened up, whereas the OEM type gave me endless grief. Oddly enough, I had a few of them on hand as I own a couple of Suzuki GS1100Es.

As to the fins being broken off. Do you have pictures that we can examine? It's possible that it has been staked in place to keep it from loosening.