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SOHC.co.uk Forums => CB350/400 => Topic started by: THUNDERDOWNUNDER on October 24, 2019, 11:12:42 PM

Title: 400/4 Exhaust Fitting Info needed
Post by: THUNDERDOWNUNDER on October 24, 2019, 11:12:42 PM
I have inherited a set of replacement Pipes and collector box (Silvers ) for 400/4 . All brand new but no instructions . The pipes are marked 1 2 3 4 . My question is which way round do they fit the collector box ? I see on one side of said box has a fitting for a retaining bolt ( I don’t have ) The other three slots have nothing to hold pipes . So looks like press fit ! Any help welcomed.
Title: Re: 400/4 Exhaust Fitting Info needed
Post by: taysidedragon on October 25, 2019, 12:03:43 AM
I've got the same set on mine. The clamp on the collector is on the underside,  this puts the silencer outlet to the outer righthand side of the bike. The pipes are obvious then. The longest pipe goes from furthest cylinder to corresponding collector inlet and so on until shortest pipe goes from righthand cylinder to the righthand collector inlet. I used some exhaust paste on the push in pipes to make sure they sealed.
See Gallery photo of my CB400F Cafe racer 2.

Ps. It's a bastard to fit!

I just remembered,  Fit the silencer to collector box first, helps to line up the mounting points.
Title: Re: 400/4 Exhaust Fitting Info needed
Post by: THUNDERDOWNUNDER on October 25, 2019, 01:52:38 AM
Thanks taysidedragon , invaluable help there . Yes I was thinking of useing a bit of heat on the collector box to help get the pipes in as they seem reluctant to fit . Did you push them to a stop or is it see how you go ? Hope you didn’t get any leaks .i wonder if the clamps (Silvers )are selling would help seal it ? Rob .
 
Title: Re: 400/4 Exhaust Fitting Info needed
Post by: paul G on October 25, 2019, 08:15:50 AM
Clamps won't do anything as there is no slots on the other three inlets on the collector.
Title: Re: 400/4 Exhaust Fitting Info needed
Post by: THUNDERDOWNUNDER on October 25, 2019, 08:36:44 AM
Had a go at fitting down pipes to collector box . No Luck  . If they are this hard to fit they aren’t going to leak that’s for sure !
Title: Re: 400/4 Exhaust Fitting Info needed
Post by: taysidedragon on October 25, 2019, 10:00:16 AM
Thanks taysidedragon , invaluable help there . Yes I was thinking of useing a bit of heat on the collector box to help get the pipes in as they seem reluctant to fit . Did you push them to a stop or is it see how you go ? Hope you didn’t get any leaks .i wonder if the clamps (Silvers )are selling would help seal it ? Rob .
 

Mine slid in nicely with a good close fit. I pushed them in as far as they would go but had to ease a couple back out a little to adjust the fit to the head. No leaks.
Title: Re: 400/4 Exhaust Fitting Info needed
Post by: THUNDERDOWNUNDER on October 25, 2019, 11:24:05 AM
Thanks these are. going to be a challenge but if they can put a man on the moon I can sort this out !
Title: Re: 400/4 Exhaust Fitting Info needed
Post by: Laverda Dave on October 25, 2019, 11:43:31 AM
As Tayside said in an earlier reply, they are an absolute pig to fit and you will get angry >:(!  You will think they are bent or twisted and not to spec but they are! Mine kept hitting the sump pan and it took forever to get enough clearance.  Don't do anything up tight (including the exhaust collars at the head) until you have everything aligned and then go around tightening the clamps etc in stages checking clearances all the time. A bike lift makes things a lot easier, I spent most of the day on the floor!
Title: Re: 400/4 Exhaust Fitting Info needed
Post by: THUNDERDOWNUNDER on October 25, 2019, 10:36:18 PM
Thanks Laverda , I am having trouble just getting the pipes to fit into the collector box so if it’s going to be a bastard with the rest of the set up I may have to set aside a weekend to have a go . You would think as the pipes are all numberd it would be a breeze so thanks for the warnings . In God we trust . All others pay cash .
Title: Re: 400/4 Exhaust Fitting Info needed
Post by: THUNDERDOWNUNDER on October 27, 2019, 07:06:40 AM
Well it’s a nice day here 35 degrees in the shade . Left the Collector box in the sun for a few hours and had to wear gloves to pick it up . Put cold down pipe to collector box just managed to get it started a few mill and that was it . Maybe I need a hotter day ?
Title: Re: 400/4 Exhaust Fitting Info needed
Post by: taysidedragon on October 27, 2019, 09:58:31 AM
That sounds too tight. Are the pipes out of round and causing the binding?
If not you may need to remove a bit of metal to ease the fit. A gentle dremel round the inside of the collector pipes?
Title: Re: 400/4 Exhaust Fitting Info needed
Post by: THUNDERDOWNUNDER on October 27, 2019, 11:44:44 AM
Funny you should say that . I will try a socket on it tomorrow for roundness . If all ok will get the dremel out or lots of elbow grease with the emery paper ! Thanks for all the input guys !
Title: Re: 400/4 Exhaust Fitting Info needed
Post by: THUNDERDOWNUNDER on October 27, 2019, 11:27:32 PM
Just another thought on this . Why is there only one retaining clamp on the collector box ?
Title: Re: 400/4 Exhaust Fitting Info needed
Post by: taysidedragon on October 28, 2019, 11:03:59 AM
Just another thought on this . Why is there only one retaining clamp on the collector box ?
Good question. I guess it's cheaper to manufacture and when it's all assembled just one is enough, the others can't move.
Title: Re: 400/4 Exhaust Fitting Info needed
Post by: THUNDERDOWNUNDER on November 03, 2019, 06:48:35 AM
Problem fixed .slight lip on collector box inlets . Looked like build op of Crome platting . Filed it flush . Just have to assemble them now Agh !
Title: Re: 400/4 Exhaust Fitting Info needed
Post by: taysidedragon on November 03, 2019, 10:01:20 AM
Good luck!
Do you know any gynaecologists to lend you a hand , or 3?  :)
Title: Re: 400/4 Exhaust Fitting Info needed
Post by: PatM on November 03, 2019, 04:30:50 PM
Im a fan of that set as I went through  the mill trying to polish my rusty pipes and tried to get a re-chrome for a reasonable price-but no luck with that one. My rebuild was always going to be on the cheap as Ive a few other bikes to concern myself with-oh and them 4-wheeled things.
So, 9 years ago those kits came out and I bought and fitted one-its not a 1/2 Hr job as they either don't fit the head or wont seal-As said-theres only one retaining bolt but they are a decent fit into the collector box and a smear of paste does the job of sealing. I know this sounds heresy, but I had to grind a few of my collets down to get them to fit. The result was pleasing and I had  nice shiny exhaust system as opposed to 3 rusty pipes with no chrome and a welded collector-box that was more weld than metal.
As I said, 9 years now on and yes, they have discoloured as they are single-skin, but they are far better than what was on there-even though I had a few rusty sets of pipes/boxes to mix n match.
Title: Re: 400/4 Exhaust Fitting Info needed
Post by: THUNDERDOWNUNDER on November 24, 2019, 05:22:25 AM
Sounds encouraging and thanks for the info I am going to need !
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