Q. I have a 2002 Fazer 600, with K&N filter and Micron end can.
I'm thinking of replacing the standard downpipes with a stainless steel set, but I've noticed that the replacement system has a larger bore and I've been told that this will decrease the midrange, which I really don't want to lose.
Is this true? If it is, do you know of anything that I can do with the standard downpipes to prevent them rotting? I've considered having them chromed, but it's expensive and will only last two years, so I'm told.
A. Used downpipes won't take chroming so that's not an option.
As your bike is carburated, and the pipes you are thinking about are bigger, you'd be looking at a re-jet, as the bike runs pretty lean in the first instance, and any increase in the pipe bore will affect the midrange as you suspect.
It might affect the total power too, especially as the Micron end can is less restrictive, along with the K&N air filter, which will allow more air through the motor, leaning it out.
If I was buying aftermarket pipes I'd make sure that they'd been dyno tested as proof that they don't adversely affect the power, I'd also ask searching questions about how they fit, as some have been known to foul bodywork, or the frame.
British-made Motad downpipes are £100 more than some Far eastern facsimiles, but they have been developed on the dyno, have a similar bore to the originals, and they fit...