New exhaust pipes needed

JimC · Aug 20, 2013

Captain Mandrake said:
Would that faulty Boyer stator have been a broken pickup wire? The break is usually inside the insulation, therefore not visible. If so, how was it repaired? If the stator was replaced with a new one, likely as not you'll have the same failure again.

As I recall, it wasn't a broken pick-up wire. The entire staror was replaced and I haven't had the misfire return. Thankfully.

Cheers

There have been many problems with the Boyer stator plate wires fracturing, causing a misfire. The break usually occurs inside the insulation. Soldering the wires to the pickup coils is the problem. A search of this topic here will give you a lot more knowledge about the problem. The fix is quite simple and cheap.

bentrod · Aug 20, 2013

CanukNortonNut said:
Captain Mandrake said:

Hi CanukNortonNut, seems we're in the same neck of the woods.

I was going to use the old rose nuts - not clear the collets would be needed with these and unbalanced pipes. Are the new genuine Andover Norton rose nuts longer and therefore don't require the collets? I read this thread ( engineering-compromises-leading-exhaust-threads-stripped-t14363-15.html ) and am a bit unclear, or maybe just not confident enough to come to any conclusions on my own! I'd rather not spend the extra $50 each for new genuine ones, but if they're what's needed with the unbalanced pipes...
Cheers

Click to expand...

Capt.M,
I would not recommend using the 850 crossover style rose nuts if you go to straight pipes. This design is used with crossover system and the collets. You would end up doing the work on your head from the link that you entered in your reply.
The better way IMO is to get some Bronze or Chrome Plated bronze early style rose nuts from Walridge motors. These expand better with the Aluminium Head than the Cast steel ones that you have. A properly seated Bronze rose nut with new exhaust gaskets (Run the bike at 3-4000 RPM while turning the rose nut till tight) will not come loose. I do not use the locking rings with the tabs or lock wire. I Have two paint pen marks on my rose nuts to watch if they move and It hasn't moved in two years and 10000 miles. Using the ones you have may seem like a good economical way to save costs but trust me, don't use them on a single straight pipe system. Keep what you have (Crossover system) and get it repaired at a weld shop. Rick Harret Highway Cycle in Waterdown would be a good guide locally for you and there is a weld shop right next door. He would be able to order all the bits for you.
Cheers,
Thomas
CNN

The 73 Commando I referbishing came with the cross over pipes. There not in that bad condition and the rose nuts are in very good condition. I bought new straight pipes to go along with new peashooters. I was not aware of the difference in the rose nuts. I looked at Walridge parts catalog but its unclear to me which of the nuts I should be looking at for the straight pipes. Do you have a part number? Also, is it possible that someone here would be interested in trading crossover pipes with the nuts and collets for the proper nuts for straight pipes.

Art

CanukNortonNut · Aug 20, 2013

Bentrod,
06-2464 exhaust nut “genuine” is what is on the invoice when I ordered in 2011. You can get these from any vendor that supplies AN parts. Bronze (which is colored such) or you can get them in chrome plated. This system expands similar to the head as it warms to operating temps. I would much rather have two more threads turned into the head threaded area for support than an added exhaust gasket to the too short 850 style exhaust rose nuts. It doesn't help in this weak spot on the head. I had to repair my combat head from this “Lesson learned”. Maybe a few more on this forum… has been there…done it…. know all about it.
When I bought my first Combat in the early 80's, I thought that it would be a "good Idea" to go to the 850 style rose nuts. I learn a valuable and expensive lesson not to do it. By the way the best repair to the exhaust thread that I inspected was from comnoz on a buddies 750 head. But we don't want to go there. :roll:
Cheers,
Thomas
CNN

Captain Mandrake · Aug 26, 2013

I just received my order of parts. The pipes seem to be a good fit, but I can't say the same for the exhaust nuts. Following the advice I received earlier in the thread, I went for the earlier, longer ones. I asked for the genuine Andover Norton. They didn't come in the usual AN bag with the paper claiming them to be genuine parts - the price certainly reflected that... Should I be suspicious? And they seems too tight, unlike my stock 850 ones... Too tight to go on by hand... Threads seem fine so I'd rather not force things - didn't thread them in. I didn't go any further as my supplier is closed for the day and I want to be sure that they're the parts that I paid for, not aftermarket. Should they be so tight that I would need the wrench just to snug them in all the way? I didn't try to do things properly using anti seize as I don't want to have any issues returning them if they're not actually what they're supposed to be...

Hobot · Aug 26, 2013

Once pipe aligned and treads begin to engage should be able to turn most the way in by hand but does take a glove after about half way in while jiggling. Anit-sieze does help ease em in but just washes right off so should not spoil the parts but protect their surfaces, some what. Run old ones and new ones in w/o pipes and see how they compare to decide.

CanukNortonNut · Aug 26, 2013

Capt.
Try to clean the threads in the head with a small welders wire brush. They look like a tooth brush except they have a wooden handle. Crappy Tire carries them or Princes Auto. Brass or better yet stainless bristles. This is not an uncommon thing with the rose nuts to the head being tight compared to the 850 style. Mine were the same way. Tight. Just insure that you are not cross threading them in. You can also try switching rose nuts to see if this engages the threads a little different. Try putting them in just on there own with out the pipe in place. It might be that the pipe is binding things up. Who did you buy your parts from?
Cheers,
Thomas
CNN

Niagara850 · Aug 26, 2013

Had a similar problem, I chased the threads with the slot end of a small L screwdriver with a few squirts of brake cleaner and a tooth brush. I could screw them in by hand without the headers on. I also went with the 750 header pipes and bronze exhaust nuts with some Permatex Ultra Copper on the threads. Tightened it all up, ran it around the block retightened hot, hasn't moved in 2000 miles.

Captain Mandrake · Aug 27, 2013

I picked these up from British Cycle in Nova Scotia. Called them this morning and they say that despite the packaging, they are the genuine Norton. They said they'd take them back.

I have cleaned the threads with a stainless brush as suggested. As the original 850 nuts fit well (although looking a bit worse for wear), I think I'll have to use them. Or call Mike @ Walridge and see about the bronze ones - maybe they'd be a better fit?

Will try them once more, when time permits, just to be sure it is the nuts and not myself who is at fault. Thanks for weighing in.

Cheers

Niagara850 · Aug 27, 2013

The threads are the same so they should go in with agood thread cleanup. Are the threads damaged? Mine were tight until I cleaned up the threads and one wanted to cross thread. There was some minor thread damage on it from the nut rattling loose at some point during it's life and the offset slot screwdriver chase helped that out and its been good so far. When I acquired the bike the header was cracked and the exhaust nuts were a mess, fins broken, drilled and wired the barrel fins.

I've dealt with Brit Cycle and Walridge and find them both reputable and helpful. Moto GP in Montreal as well. Spread my business around depending what is in stock and how fast I want to get it.

Hobot · Aug 27, 2013

Yeah man on them goldenish rose buds, gives a nice touch of steampunk splash besides similar thermal expansion as Al. Seems to like rubbing up on Al more than the steel does. I have run into this confusion hanging up free screwing in, not to be confused with free loving of course. Note this is not my picture and more extreme than most but well with in the Commando supply chains.

CanukNortonNut · Aug 27, 2013

Looks like a production racer tube on the right. Tucks it closer to the frame.
Cheers,
Thomas
CNN

CanukNortonNut · Aug 27, 2013

Captain Mandrake said:
I picked these up from British Cycle in Nova Scotia. Called them this morning and they say that despite the packaging, they are the genuine Norton. They said they'd take them back.

I have cleaned the threads with a stainless brush as suggested. As the original 850 nuts fit well (although looking a bit worse for wear), I think I'll have to use them. Or call Mike @ Walridge and see about the bronze ones - maybe they'd be a better fit?

Will try them once more, when time permits, just to be sure it is the nuts and not myself who is at fault. Thanks for weighing in.

Cheers

Check them with a magnet to see if they are steel. Again the bronze or Chrome plated bronze will expand with the aluminum head as hobot stated. What tool are you turning the rose nuts in with? The Norton tool for this is quite robust.
Never seize would make things easier.
Cheers,
Thomas
CNN

Captain Mandrake · Aug 28, 2013

I have the Norton tool - and since it offers quite a bit of leverage I worry about doing in the threads. I ordered a set of the bronze nuts after all as I imagine I'm returning the others.

Hobot · Aug 28, 2013

Have no fears but tool alignment-grip to wham bam or body slam on the bronze rings, so once does it, the threads can take it no problmeo. Loose threads is what takes out the Al side not over tight, which takes out ring bolt fins or lugs.

New exhaust pipes needed

Similar threads