Honda-SOHC

SOHC.co.uk Forums => CB350/400 => Topic started by: Myford on December 06, 2014, 05:09:47 PM

Title: Blue pipes
Post by: Myford on December 06, 2014, 05:09:47 PM

Hi all
New to this forum, been lurking for a while.
I've been a Brit bike man all my life, but I've always liked the 400 fours, and now I seem to have ended up with several to build one out of. I've been following the exhaust thread with interest and I just wondered about the mention of exhausts turning blue if they're not double skinned. Why?
With brit bikes if the down pipes (single skin) are blue it's considered a bit of a poor show really.  It usually means you've either got the mixture or the timing wrong .
So what's different.
Just curious.
Terry

Title: Re: Blue pipes
Post by: Trigger on December 06, 2014, 05:45:31 PM

Welcome to the world of the SOHC.
If a exhaust is double skinned it will not blue at all. I am not sure were the british bike owners get that myth from. All motad exhausts blue straight away even if the mixture is spot on.
I do a lot of work on drag bikes running NOS and they love the look of blue down pipes. 

Title: Re: Blue pipes
Post by: Johnwebley on December 06, 2014, 06:58:48 PM

when I had brit bikes,Triumphs 5ta and BSA A65,gives you some idea of my (great) age,
blue pipes were a sign the bikes ran hot and clean,

Title: Re: Blue pipes
Post by: Bitsa (Ralph Wright - RIP) on December 06, 2014, 07:20:13 PM

Sorry but to me cheap crap exhausts I hate blue pipes with a vengence.Why should any correct running engine give the false sign of, shit must be a weak or whatever something is wrong
Never known one jap exhaust to blue unless something is seriously wrong.Remember a mate who had a triumph cub that went cherry red until he realised the timing was out.That has all ways put me off brit bikes.
Cheers
Bitsa

Title: Re: Blue pipes
Post by: Clem2112 on December 07, 2014, 11:04:27 AM

If anyone wants the blue/yellow look and needs the two clamped headers (DSS) I have these going spare. :)

Title: Re: Blue pipes
Post by: Lynx on December 08, 2014, 10:53:13 AM

I have DSS replicas on my bike. The down pipes had not discoloured until recently. They've done about 700 miles. Now the near side 2 down pipes have started yellowing. I've taken the plugs out and it is definitely running lean on those 2 pots. I haven't looked into why yet but I guess it is carb balance to blame.

Title: Re: Blue pipes
Post by: Myford on December 16, 2014, 08:46:45 PM

Thanks for that guys,
some interesting posts there.
Terry