Exhaust lockring alternative?

Help a newbe out: I'm excited about getting my Dad's Norton on the road again after many years of sitting.

My 75 MKIII right side header was loose and when I went to tighten it I decided that the exhaust lockring looked kind of boogered, so I'm thinking I will replace them. Although I own the original balanced pipes it currently has a 2 into 1 setup on it (that my Dad put there in 81 and I'd like to leave there for sentimental reasons). It must have an issue of loosening on that side, because it looks like my Dad was always tightening that side. I have the right tool for it, but the fins are so notched that it is loosing its effectiveness.
:? In fact I'll probably have to break out the channel-lock pliers to get it off (at least its not stuck - its loose).

It currently has this kind of lockring on it http://www.norvilmotorcycle.co.uk/063988.htm

Can I put this kind of bronze lockring on there? http://www.norvilmotorcycle.co.uk/010399.htm

Are there other parts in there that I should replace at the same time or is it OK just to do the lockring?

Since you already have a two into one just using the bronze nuts and new crush washers should work. The stock 850 nuts were shorter and prone to destroying the head threads. Be sure the new bronze ones you order are the 750(longer) type. Also before you fall too far in love with the two into one be sure they are not the type that bend the front fender when a ditch is crossed. It gets real ugly real fast.

8) Well, I only try to cross ditches in my Jeep (35 inch tires and a slew of mods), but just in case...

Are these the kind of pipes :shock: that'll destroy a fender?

http://s31.photobucket.com/albums/c384/ ... otorcycle/

So, just for clarification - Even though I have an 850 I should get the bronze ones for a 750? Sorry, I just don't want to mess this up. :wink:
I've regeared diffenentials and rebuilt engines, but motorcycles are new to me and I'm paranoid.

And by the way... Thank you for the quick reply!

Yes 750 ones will work better it's the cross over that mandates the use of the shorter pieces. Can you ask Dad the brand of header? They do come out straight from the head a ways before making the curve.
On travel: It looks OK but only one way to tell for sure. Using a jack for support that will collapse very low (like a floor jack) pull the top bolts and let the bike down slow allowing the springs to come up out of the triple tree till the forks bottom out , now turn them lock to lock slowly. You can change the fork oil while doing the check and kill two birds that way. Nice to know both are in good nick.

If the two into one pipes will separate at the collector and you can slip the lockring on from that end, then you will be able to use the 750 lockrings. If not, you will have to use the 850 rings because you can slip these over the flange at the head end and then insert the collets.
The 750 rings will not pass over the flange end.

As Ron states, 750-style rings slip on from the end of the pipe, as they don't fit over the flange. 850-style rings, like the ones you currently have, are designed to slip over the flange, and then 2 locking collets are fit into grooves in the exhaust pipe. the lock ring holds the exhaust in place by locking against these collets (similar to the collets that hold valve springs in place).

With either of these, there is also a tab washer that keeps the lock rings from loosening. It has to tabs that fit over a head fin, and two tabs that are bent between fins on the lock rings.

Ron, in the third picture I can see a clamp on the timing side of the muffler. I sure hope they have on on the primary side.

Ron, in the third picture I can see a clamp on the timing side of the muffler

Click to expand...

Good eye!

norbsa48503 said:

Since you already have a two into one just using the bronze nuts and new crush washers should work. The stock 850 nuts were shorter and prone to destroying the head threads. Be sure the new bronze ones you order are the 750(longer) type.

Click to expand...

OK, I've been thinking about this and I'm confused. (realize that I have not taken the exhaust apart yet)

If the 750 lockrings are longer, therefore less likely to ruin port threads, that must mean that they thread in further and contact more threads... right?

If the 850 ones are shorter, how do they seal? It seems like they couldn't reach where they need to. What am I missing here?

I'm very interested in this because I'm afraid the port threads are already worn and this seems like a good bit of insurance.

The 850 type use wedges that are pushed ahead of the retainer. this makes up the distance but there is less thread engagement. You need a parts manual man. I see a clamp for one of the pipes going into the 2-1 collector is there one on the other side as well? If so just use the bronze 750 ones.
Also realize that thread damage comes from running the bike with the thread too loose. If the retainer comes lose you need to know, so you can fix it. lock rings and safety wire just don't work because they mask a loose retainer.

The 850 lock rings have a larger diameter hole to enable them to feed onto the pipe from the flange ((cylinder head) side of the pipe. two split collets are then fitted per side to hold the flange against the head and prevent the pipe from simply falling out of the lock ring hole. The collets are like a split 'top-hat' bush and the bottom part takes up some of the space in the thread port. This is necessary on pipes with a balance pipe because you cannot fit the lock rings over the balance pipe stubs from the exhaust side.

The 750 lock rings are fed on from the exhaust end of the pipe and have a smaller diameter hole that buts up against the flange of the pipe itself, the absence of an additional set of split collets enables these lock rings to protrude deeper into the exhaust port.

Norbsa we must have been typing at the same time. I agree with your view that lock tabs and lock wire can both mask and exacerbate a loose lock ring situation because they tend to come loose and then chafe in position, doing more damage than if they had actually fallen out completely. i have used the bronze rings with very good results.

Thank you gentlemen very much.

I'm sure I'll have more questions to come.

The one thing that use to annoy me about lockrings is their loose fit.

Simple solution, make some washers out of brass or copper machined separate to fit each side to take up any slack, the lockrings dont move or wear any aluminium on your head, and your nuts will never come loose.

Welp, It looks like I'm in the market for some peashooters. The 2 into 1's are welded and the original beancan pipes still hanging in Dad's garage have the balance pipe on them. I figure that buying unbalanced peashooters would be better than risking more thread damage. Any tips on where to get some?

Afterthought...

Since money is always an issue and I would like to keep the original parts on it; Can I just buy new unbalanced 750 head pipes and clamp on my Dad's original beancans? It looks (according to old Britts catalog) like they have different part numbers, but both nuts are 3/8 x 24 and both bolts are 5/16 x 24, and both clamps are 1 1/2 inch, so it seems to me like no big deal.


In case the above didn't sound like a question there is one in there, Can anyone verify that this crazy plan would work? Thank you!

Captain B said:

Afterthought...

Since money is always an issue and I would like to keep the original parts on it; Can I just buy new unbalanced 750 head pipes and clamp on my Dad's original beancans? It looks (according to old Britts catalog) like they have different part numbers, but both nuts are 3/8 x 24 and both bolts are 5/16 x 24, and both clamps are 1 1/2 inch, so it seems to me like no big deal.


In case the above didn't sound like a question there is one in there, Can anyone verify that this crazy plan would work? Thank you!

Click to expand...

Bump for an answer before I make the purchase. Anyone have any thoughts on this?

I replaced my 850 pipes with 750 pipes, and they clamped right on to my stock mufflers.

After cracking two left pipes, I switched to the 750-style pipes, which meant 2 pipes two exhaust rings and two exhaust washers (about $250, altogether).

Coming up on 4000 miles with no issues.