Exhaust nut -350

[peterc]

Needed, 1 castellated exhaust nut in usable condition please. I have one, and have stainless ones on order at NLM, but they don't have a delivery date as yet. Thanks.

[Chips1953]

Hi, I have one you can use, it's usable but not nice to look at.
PM with address if you want it.

[peterc]

Thats great, thanks. pm sent

[Chips1953]

I have sent this nut to "P" but it may not be acceptable,(bit grim) so if any others have something then him know.

[nickst4]

I have a brand-new unused one that I don't expect to need, being as my Dart has two perfectly-serviceable items which are barely visible anyway. I don't know what its worth but if Peter is only needing a stop-gap, maybe I'll hold onto it. The secret, so far as I'm concerned, is to have a proper spanner to tighten them, rather than resorting to the nasty business of using a punch. Mine are also now wired, so all should be good...

Nick

[peterc]

Thanks, Nick, hang on to it - I'll be buying a new pair when they become available, it was just to keep me on the road. I'm sure there was a source other than NLM for these (Germany or Italy?),but can't find any reference to it as yet. I agree on the lock wiring, though it seems most owners don't bother.

[hombre]

Hi guys, Mauro Gini in Como-Italy makes them as well: http://81.122.83.150/accessori-gini.htm

He also has a good spanner for them. It works only on new ones I found out though.

If anyone needs a hand on translating to Italian let me know!

[peterc]

Great, that looks promising. I'll send him an e-mail using the on-line translator & see how I get on

[Monstyr]

Thats where I bought mine, and very nice they are too.
The language barrier wasnt too much of an issue I found.

[hombre]

Great, that looks promising. I'll send him an e-mail using the on-line translator & see how I get on

Ok! I always find these translators very amusing. Let us know what he will send you

[EVguru]

I agree on the lock wiring, though it seems most owners don't bother.

It's a hideous botch!

I've never had a correctly tightened nut come loose, but if you are having a problem (or just want to be sure), then the elegant way to do it is a nice slim stainless pipe clamp with a tab welded on to engage one of the castellations.

[nickst4]

I agree on the lock wiring, though it seems most owners don't bother.

It's a hideous botch!

I've never had a correctly tightened nut come loose, but if you are having a problem (or just want to be sure), then the elegant way to do it is a nice slim stainless pipe clamp with a tab welded on to engage one of the castellations.

Hmmm, I think I'd reverse those comments! Properly done with lockwire pliers, I can't imagine anything neater than a discreet wiring, and it lends an exciting air of professional racer to the plot.

Each to his own, though. I appreciate that the cosmetics are more relevant to the traditional naked Morinis than the Dart, where the installation makes it very awkward to tighten those rings adequately without special tools....

Nick

[George 350]

Nick,
Whether you feel that lock wire looks 'racy' or not, the bottom line is that provided that they are done up properly, they don't come undone. Of course, the complete system must be fitted properly so as to not stress the head end joint or allow any extra vibration there.
if you are familiar with the old Norton twins, they use a very similar fixing method of threaded ring/sleeve nut directly into the head, and again provided they are done up properly they stay tight, even with the vibration that a 360* parallel twin throws at them. (Commandos would break the pipes before the ring came undone, but then their engine and exhausts are rubber mounted)

You need good threads in the head, a small amount of never-seez or copper slip on the thread of the castellated nut, good (new) gaskets and most importantly a very good fitting C-spanner.
1/ With system fitted but no joints tightened, lightly nip up pipes at the head.
2/ Tighten silencer brackets to frame.
3/ Tighten castellated nuts really well.
4/ Tighten joint clamps.

Run the engine and get the engine nice and warm, then give the castellated nuts another good heave and in my experience they will then stay tight forever.
if you don't use some lubricant on the threads, my own experience is having the castellated nut seize into the head. Back in 1997 it took a week of soaking the head and down pipe in a bucket of diesel before I could separate the joint and the nut was destroyed in the process. When I did the renovation last year, the pipes were still tight and came apart quite easily.

[nickst4]

Nick,
Whether you feel that lock wire looks 'racy' or not, the bottom line is that provided that they are done up properly, they don't come undone.

George, thanks for describing the way you fit your exhaust. All of that is familiar to me, as a biker of many year's standing. My only comment is that you would not appear to have had experience of doing the job on a Dart!

I realize that there are very few of us here that care to mention the 'D' word on principle, much less grapple with that model's little idiosyncrasies (Personally, the Dart is the only early vee-twin Morini I have the slightest taste for, but then I'm a committed Cagiva man too ). Basically, access to the rings on a Dart is very difficult, making their tightening much less easy than on the other models, unless you fabricate a separate tool for each ring, which I have. Now that mine are snug but not overtightened, the wiring may well be unnecessary, but it pleases me....

Nick

[peterc]

Just to recommend the above source in Italy for bronze castellated nuts - a pair cost me £44 delivered (so about 1/2 the cost of stainless versions). They are very good quality and the proprietor is used to UK customers and google translations