Topic: 4 to 1 re-jet inevitable?

[Ernest]

I currently run a 4 to 2 exhaust.  The idle jets I believe are 38 and not sure what the main jets are.

I've been offered a 4 to 1 exhaust.  Live in the midwest USA and this is for a cb750k 4.

It will have a baffle.

What are the symptoms when you know you don't have the jets set correctly for the type of exhaust you run?  poor idle?

Do you just change the jets or do you also need to adjust to a different notch on the carb needle as well?

thanks,

[hapsh]

You will be most likely fine where you are.  Do some plug chops after the change to make sure it does not make too much of a change.  I have never HAD to change jetting for pipes except on my 2 strokes.  You can sometimes benefit from going a bit richer on the main jet after the pipe change to compensate for a slight leanness.  But you won't make your bike dangerously lean from the pipe change.  It is usually subtle in change and only at or around WOT.  The only way to tell for sure is to do plug chops before and after the change.

[Ernest]

cool, thanks