Baffling problem

[Jem Wilton]

I have just got around to replacing the silencer on My 1989 R100gs... My old silencer had been cut, shut and opened again 15 times and gave very little baffling effect. My new (secondhand) Keihin is lovely, but it's baffling the motor so much that I can hardly hear the old bumblebee anymore. I'm getting older so a quiter exhaust is actually quite a blessing... what I really wanna know is: will I have to alter the carburation at all to make up for the greater back pressure? I can ride the bike for a couple of weeks and work this out I suppose, but if any of you well-informed airhead users have a steer for me that would be cool...

 

[robertotoole]

When I swapped from a Laser Produro (great silencer) to a Keihan (horrible) I didn't change the carbs. Not even retuned. Same when I changed the downpipes to ones without a link pipe.

Now you've got me thinking about the exhaust! I really hate my Keihan silencer. Looks crap, sounds crap, weighs a tonne.

The Laser made such an awesome sound. Growling and popping.

 

[Wrigsby1]

The thing about old carbo bikes is 90% of your tuning is felt via your right hand... If it's pulling cleanly, not lagging, revving through the range then it's usually as is... A plug chop makes sure but many BMs show lean colours anyway as normal... Good thing is checking the jet numbers etc is easy with sticky out carbs... I bought a Kwak 4 this summer with 80s tech and even trying to get to anything on the carbs is a nightmare as I found replacing the fuel pipe... Luckily things are OK apart from that....

 

[Kenny]

If no one has previously tampered with the carburettors, then Keihin is simply 'plug and play'

 

[Jem Wilton]

If no one has previously tampered with the carburettors, then Keihin is simply 'plug and play'

Ha - after quite a few years running the old bastard on what were effectively 'straight through' pipes, I can safely say that yes, the carbs have been tinkered with. I think the Keihin will be fine, it will just be a case of getting the new 'feel' right.

 

[Wrigsby1]

Ha - after quite a few years running the old bastard on what were effectively 'straight through' pipes, I can safely say that yes, the carbs have been tinkered with. I think the Keihin will be fine, it will just be a case of getting the new 'feel' right.

If you have a Haynes manual or similar they will give you the standard jets, needle setting etc as a reference...