After market pipe question

I was once a poster here a long, long time ago when I was the owner of a 03 B1200S and later an 07 B1250S.  For some years I've really missed my B1200S and an opportunity has presented itself to buy an O4 model and here's my question. 

The bike comes fitted with a genuine pipe and a Staintune in the box.  I asked why it wasn't fitted and the owner said he had troubles with the way the bike ran ie he said it was running too lean and needed rejetting.  I had a Staintune pipe fitted to my 03 and didn't have a drama.  Were there any changes to the exhaust/emission control system in 04 which would cause running problems with an aftermarket pipe?  Or is there some other reason?

Thanks in advance,

Tony

I believe if you only change the slip on muffler on it's own , or change the air filter on its own you can usually get away with it , but if you change both , a re-jet is required ( maybe the air filter has been changed )

If it breathes better, whether that be from a exhaust or intake mod you may get a lean mixture, only way to know for sure would be a run on a dyno

Thanks for the info gents.  I may have been lucky with my 03 with a Staintune.  That's a good suggestion re the air filter and I'll check that with the owner.

Thanks again.

Hi mate,

I`ve got an 03, and have had for 11yrs.

Way back when, I started playing and changing things, at the same time I first did k&n and "CAN" change, it gave a mid range flat spot.

 I lifted the needles, to richen it, and fixed the flat spot through trial and error, but later dynode it to get correct AF.

So IT will be a simple case of tune.

Some say they don`t have any problems doing the said alterations, but I definitely did, and needed tweaking.

Don't forget altitude will play a part and the quality of fuel will make a difference also.
The Staintune being a longer can will probably have less of an impact that a super shorty.
I'd balance carbs first.

2wheelsagain wrote:Don't forget altitude will play a part and the quality of fuel will make a difference also.
The Staintune being a longer can will probably have less of an impact that a super shorty.
I'd balance carbs first.

just remember, all that is happening when syncing carbs, is only correcting butterfly action, so they are in sync together, and have the same flow rate . It won`t correct anything else.

So if they`re not stumbling with the standard can now, it probably won`t  make much difference with the after market on, but of coarse should be your starting point any way before correct AF measurements

The owner probably didn't like the popping on deceleration from the anti pollution system.  I doubt it was anything else

Thanks again for everyone's input. I inspected the bike today and was bitterly disappointed. It was described as being immaculate but was in a filthy state. It had just less than 24k on it.....what a shame! I think the suggestion regarding the air filter was spot on. I asked the owner if the air filter was genuine Suzuki but he stated it was a K & N. Anyway, the search continues and thanks for your help. This site is a very valuable source of info and much appreciated!