Exhaust Lock Nuts

Niagara850 · Aug 10, 2010

I am looking at replacing the Exhaust Lock Nuts on a 74 850 along with 750 exhaust headers. Do you replace with 750 lock nuts or 850 ? I see what appear to be bronze alloy nuts on ebay for $175 and another set material unspecified for $46. From cruising the forum I understand that bronze is prefered but the others are 1/3 the cost. Do they work using the tighten when hot after every ride until fully seated

My current set up

Exhaust Header and Lock nut by niagaraz, on Flickr

Captain B · Aug 10, 2010

I used 750 bronze nuts on my 750 headers installed on my 850 motor. No complaints. I got some used bronze nuts on e-bay for $25. They were pretty ratty, but work well.

Hobot · Aug 10, 2010

I fitted bronze nuts on factory Combat Trixie and works same or better than steel ones. I snagged an Al set that I'll use on Ms Peel but ain't tested. May still have hard copy invoice of source, lost last 3 years ebay emails accounting losses.
Main thing is to nip up super tight and/or use springs that tend to tighten as wire will slacken and washers crush down to let thread lesson enough to beat up even if not fall off or exhaust leak till later. Factory tabs frowned on for same reason.
Every Commando rider should have at least one event riding peacefully along when a header falls out at speed or fractures apart near exhaust -hollow bolt retainers.
Full auto shot gun sounds and flame gives a lasting impression.

swooshdave · Aug 10, 2010

That's some gnarly looking safety wire.

Hobot · Aug 10, 2010

Here's description of the 3 or 4 types of factory exhaust head 'retainers' and spring solution.
http://www.nortonownersclub.org/support ... d-spanners

DogT · Aug 10, 2010

Walridge has the bronze ones for 750 (01-0399) and 850 (01-0388) right around $29CAD ea. They are real nice.

Dave
69S

Rich_j · Aug 10, 2010

Niagara850 said:
I am looking at replacing the Exhaust Lock Nuts on a 74 850 along with 750 exhaust headers. Do you replace with 750 lock nuts or 850 ? I see what appear to be bronze alloy nuts on ebay for $175 and another set material unspecified for $46. From cruising the forum I understand that bronze is prefered but the others are 1/3 the cost. Do they work using the tighten when hot after every ride until fully seated

750 headers need the longer 750 locknuts.
There's nothing wrong with the standard nuts, they work perfectly well as long as you tighten when hot with a 2ft extension on the standard tool. No springs, no tab washers and no lock wire needed- don't worry you won't strip the threads unless they're already worn out.
I've never heard of anyone who does this having any problems with locknuts coming undone.

britbike220 · Aug 10, 2010

I used standard 850 nuts I bought from old britts and they have remainded tight for 8 years. It took about 3 or 4 heat cycles to get them good and tight, but once tight they don't come loose. I do check them once or twice a season. I tried those lock washers, but they were garbage and I threw them away.

ashman · Aug 10, 2010

Hi
I got 2 new header pipes bent up in 1979 for my 850 Featherbed frame Norton using a mandle bender and have never used locking tabs or spring or wire, in all that time they have never come loose at all as long as you use a big pair of stilson or a very long C spanner to tighten them, but when I had the standed headers on the Commando frame I had to tighten them up all the time, I think most of the problem is with the standed pipes is the balance pipe between the headers as I don't have any problems when I made the new pipes without the balance pipe...

Ashley

splatt · Aug 11, 2010

Best method I have found on here so far come from the man from Belgium,hold motor at 3-4k and lean on the spanner, its actually a bit scary.

maylar · Aug 11, 2010

Your 850 exhaust nuts will be fine as long as you use a thick crush washer in the exhaust port. The preferred washer is a Suzuki steel part p/n 14181-01D00 but the thick copper washers sold by Brit parts dealers work OK too. The standard thin copper washers will let the 850 nuts bottom out their threads before tightening.

Niagara850 · Aug 11, 2010

DogT said:
Walridge has the bronze ones for 750 (01-0399) and 850 (01-0388) right around $29CAD ea. They are real nice.

Dave
69S

Thats better, right in my backyard too

splatt said:
Best method I have found on here so far come from the man from Belgium,hold motor at 3-4k and lean on the spanner, its actually a bit scary.

whoa, it'll be doing the walk too

maylar said:
Your 850 exhaust nuts will be fine as long as you use a thick crush washer in the exhaust port. The preferred washer is a Suzuki steel part p/n 14181-01D00 but the thick copper washers sold by Brit parts dealers work OK too. The standard thin copper washers will let the 850 nuts bottom out their threads before tightening.

I plan to replace the nuts, they are pretty rough looking. If I use 750 nuts will the regular crush washers do?

bmwbob · Aug 11, 2010

I went with 75 style lock nut system and headers and haven't had anything come loose in years! No more locking ring, tie wire or trashed threads. Just snug it up a couple times and forget it.

bchessell · Aug 11, 2010

I have recommended for years the bronze ones from walridge.I use them on all my repairs because they are all the same size,not whatever they decide that day to cut the thread too as a lot on the market are. They are norvil bronze nuts and they stay tight.
Bruce

Rich_j · Aug 12, 2010

It always seems to me that there are two distinct camps with lockrings,
Those who have learned to pull them up hot and very hard and sleep well at night and everyone else who spends money and time trying aftermarket locking bit'n'bobs which may work if you're lucky but usually leave the engine looking ugly (bronze rings are about the only exception, they're quite pretty

) .

Exhaust Lock Nuts

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