Yoshimura R77 Slip Ons

[Lucky 85]

Mybe a silly question but...

If you get a set of slip ons do you need to get the bike re-tuned?
I would like to get some of the carbon r77 slip ons but don't have the cash to spend having new mapping/jets etc.
If I get new pipes will the bike run crap until I do get it tuned?

OK 2 questions.

My first mod was to put R77 SS/carbon fibre ends with no DB's and the bike runs perfect with no remapping or tuning.