Exhaust pipe nuts

Hi Tom,

I would suggest this is not a clamp but a place to attach a locking wire.

What I have on my machine is a bit of copper wire running from the top of one nut to the bottom of the other one thus tending to keep them tight and also allowingcheckingof the tightness. The locking washers some people use have to be bent out the way in order to check if the nut is tight so it tends not to happen. Then when the expansion / contraction cycle frets at the threads you do not notice until it is too late.

Regards

Tony

I've drilled a small hole in the fin adjacent to each Exhaust rose and then use Stainless Locking wire to secure it after it's really done up, not had one slacken off yet.

You are not using copper exhaust washers are you? They are rather prone to settling and and you find after a while you have loose exhaust nuts. Gordon.

I found that using the steel washers and the proper tool my loose nuts problems (Oh Doctor!) ceased. Locking tab washers didn't seem to be the answer. The nuts would still loosen and rattle on the washers. Wire locking was OK but inelegant. Oh, I use bronze exhaust nuts now too. All the problems occurred when I was using steel nuts. Haven't had my nuts come loose in donkeys' years. A relief indeed! Gordon.

Another trick, well not really a trick, is to re-use the old crush washers. Don't keep replacing them unless they are trashed.

The trick is to tighten hot as suggested but with engine running. Rev it to 3-4k as the nut is tightened. Mine used to loosed but not now and I don't even take the tool with me on a run anymore (I still take all the other tools though!)

All good stuff! NEVER use those steel tab washers to lock these "Nuts", that allow the "Nuts" to jiggle around and take the thread out of the head. Then it is an expensive repair job. Tighten them when hot and you should be good to go.

I plan to try RGM's new batch of nuts. They do plated and unplated brass and their own (?) special locking spanner. They look like the original pattern - no thick fin on them. The old originals, from at least 1955 that I know of, were plated steel but I never really had much problem in the days when I did fairly high mileage and long runs. One exhaust thread was well worn, probably due to nut jiggles mentioned, so I used to wire it up inelegantly around the head fins - no hole in the fins. Now that I have the residue of around 90 metres of 20 swg stainless, aircraft quality tying wire, it should be just enough to fix BOTH nuts.

Actually I plan to get RGM to Helicoil the dodgy thread as I don't like the idea of removing anything more than a minimal amount of cast alloy material for billet aluminium inserts. Helicoils are also almost invisble when assembled. I was thinking of using the compressible copper washers - I'll try both types when the time comes.

Has anyone tried the setting version of gasket cement on them or one of the Loctite glues?

Cheers, Lionel

Stainless isn't going to have a hugely different coefficient of expansion to mild steel - either will expand at a lesser rate than aluminium as temperature increases and so tend to loosen when hot. Bronze might be a better bet, having a higher coefficient of expansion then steel. I don't have my tables to hand so I can't quote you precise figures.

Adding to the endless sound and creative advice on exhaust nut management , my secret has alwys been to use the indestructable industrial design C spanner supplied by Norton spares dealers in the '80s (it was blue with a rubber grip) - it's cut from quarter inch steel plate and is unbendable. Tighten up nuts following completion of a Charles Atlas course (withoptional extension of spanner handle usinga length of GI water pipe)thenposition a convenient nut fin so that the tabs on the steel tab washer are a very tight fit into a cylinder barrel cooling fin, bending them over and in using a hammer and drift.

In over 30 years of owning three Commandos have never had an exhaust nut come loose.

Andover Norton's exhaust nuts have been brass for many years- you can have them plated or unplated. The "C"-spanner referred to above is 06-3968- see http://www.andover-norton.co.uk/SI%20Service%20Tools.htm.

I use that on our own bikes, and lockwasher 06-2412, but those I bend only AFTER the exhaust nut has propperly settled down after first fitment and 2-3 successive operations on a hot cylinder head (after using new sealing steel rings 06-3995) with the "C"-spanner. Have ridden about 5000 miles since last summer on the Short Stroke 750 Signal Orange Roadster now, but haven't had to touch the exhaust nuts this season.

And indeed that's just what I use - the proper Andover Norton items - with no problems whatsoever - I don't even use the lockwasher. Gordon.

I use Bronze nuts and the Blue tool with grip, tighten first and go for ride and the tighten again when the engine is hot. Then forget as they ain't coming undone.