Genuine 377 exhaust system

[Orcade-Ian]

Hi folks,
Way back in 2002 I bought a full brand new 377 system from Mr Silver (when they were cheap!)
It came in a partially assembled state with the silencer clamped loosely to the header unit but the two loose pipes and seals/clamps were wrapped separately.  Now I’ve cleared some space, I intend to assemble the other 400/4 and use this exhaust system.  I thought I would separate the silencer from the headers and when I slackened the clamp bolt it moved a few turns then started to bind up.  On much closer inspection it appears that the bolt goes through the nut and then into a threaded collar acting as a locknut.
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 This has then been peened over to prevent removal.
It’s not a problem as I’ve now sliced the peened over end off and removed the bits so it’s easier to man handle.

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After all that, my simple question is: was that normal practice on complete systems back in the day?

Ian

[kent400]

I have a new one as supplied by Honda in a bloody great L shaped box. They were supplied with the collector and the two fixed down pipes. David Silver added the two loose pipes to make the complete system and that's how he sold them. Made sense really as I can't see anyone would use their original down pipes.

[Orcade-Ian]

Hi Kent400
Has your new one got that locking piece on the end of the silencer clamp bolt as well? That was the bit I was surprised at, the peening over was at just one angle rather than all round and appears to have been done on a press.  The silver paint looks to have been put on by hand and not good quality.

Ian

[AshimotoK0]

This one was new in about 1986 ..the complete system was about £100 then as Honda had slashed their exhaust prices in some sort of promotion BUT the extra clamps were not part of the promo  and were still a ripoff price. Unused but fitted to bike and was in barn for 15 years ..if you look closely there is still a bit of straw on it . Silver paint is as applied by SANKEI (Honda OEM) . There was some on thewelds of the collector box too. BTW ..don't buy the Yamiya one it's exactly the same as DS version and made in UK by Brituro...but a lot of money landed here !


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[Orcade-Ian]

Hi Ash,
Thanks for the info and the pic clearly showing the locking sleeve nut.  I suppose the arrangement was to allow the silencer to move during fitting but not able to fall off the headers if slackened too much.  Mine has Sankei 2002 stamped underneath but I’ve been thinking I bought it before that, do you know if the 2002 is actually the manuf. date or just an ident number?  If my memory is right I think the whole system was around £150
Incidentally you mentioned D L Barr in a previous post - old Don Barr did lots of jobs for me back in the day such as MK2 Jag seats, vinyl roofs and bike seats, I was really pleased that they are still trading.

Ian

[AshimotoK0]

Hi Ash,
Thanks for the info and the pic clearly showing the locking sleeve nut.  I suppose the arrangement was to allow the silencer to move during fitting but not able to fall off the headers if slackened too much.  Mine has Sankei 2002 stamped underneath but I’ve been thinking I bought it before that, do you know if the 2002 is actually the manuf. date or just an ident number?  If my memory is right I think the whole system was around £150
Incidentally you mentioned D L Barr in a previous post - old Don Barr did lots of jobs for me back in the day such as MK2 Jag seats, vinyl roofs and bike seats, I was really pleased that they are still trading.

Ian

Mine is  also stamped 2002 Ian and was deffo bought in the late 1980's .Yes I went to school with Patrick, Don's son and the (slightly) younger brother also works there. He put a few stitches in a Bomber seat cover for me last week & wouldn't take any payment for it. a right old fashioned setup still. Another guy in Beverley who is restoring a CB72 told me that there is an immaculate one on display  in 5-ways that belonged to the founder, who sadly was killed in an accident on the IOM. Need to go in there and check it out. The last time that I was in there was when it was still owned by Ken Blakey !

My dodgy mate Roger went to the funeral of  Nev Mason the founder of NevAl motorcycles a month or so back (importer of Russian bikes ...had bike shop on De-Grey St. then on Beverley Road) ..Pat and Mike Ritchie were there ... Temple Supplies.

[TheOlderGentleman]

Every genuine system I've seen (so quite a lot) has this sort of locking clamp nut, yes.

[Orcade-Ian]

Thanks T.O.G.
That was the nugget of Info I was seeking - it seemed strange that Honda (via Sankei) should use such a strange locking arrangement making it difficult to remove the silencer from the headers.  I realise that a nyloc nut is unsuitable but there are many other types of locking device suitable for high temperatures.  BTW Ash, my Wife remembers the Suffolk trip to DS when I bought the system (and a car full of other NOS 400/4 stuff) and informs me it was 1994!  I took the 2002 stamp underneath incorrectly to be the date.

All the best to all for the New Year - unfortunately the year after that, I will be on 3 year driving licences - must get some serious miles in from now on.

Ian

[TheOlderGentleman]

When the stub from the headers sort of welds itself to the silencer, it can be an utter bitch to remove.  I even took one to an engineering works and they had a go, and said they couldn't shift it without actually destroying the joint.

[AshimotoK0]

Just removed a downpipe from a CB250G5 silencer (1976 bike) and it had exactly the same collar.

[Orcade-Ian]

Was the thread protruding from the collar peened over as well?  I can’t imagine what the thinking could have been behind that practice.
Btw Ash, you mentioned the passing of Nev Mason - did you read any of his ‘Bike Kid’ books?
Although a bit fictional they’re a good read for any Hull folk with an interest in old bikes.  I had a few emails from him and he sent me a copy of his ‘100%’ life story book.

Ian

[AshimotoK0]

Was the thread protruding from the collar peened over as well?  I can’t imagine what the thinking could have been behind that practice.
Btw Ash, you mentioned the passing of Nev Mason - did you read any of his ‘Bike Kid’ books?
Although a bit fictional they’re a good read for any Hull folk with an interest in old bikes.  I had a few emails from him and he sent me a copy of his ‘100%’ life story book.

Ian

Yes ...  peened over thread Ian. My mate Roger (who was once at BE Brough semi-skilled) worked for Nev in the 70's machining parts and modifying the Russian bikes he imported and badged NevAl , in order to comply with UK regs Never read his books but Roger has. http://nevmasonbooks.com/

[AshimotoK0]

Still out there ... at a price. Anyone on here?

https://www.ebay.co.uk/itm/Honda-CB400F-1975-1977-NOS-1830-377-017-exhaust-Silencer-HM377-brand-New/253353474550?hash=item3afd0b39f6:g:i9UAAOSwoBlaUnjK