now then lads, just bought a fzr400 off my mate as a favour, never had a fzr before, my other bikes are 2 ZX10R's, so quite a difference.
welder by trade (any work welcome) was wondering if you can just buypass the exup the valve and motor with a straight through link pipe? will it effect starting/fueling etc?

Congrats on the FZR

Have a look in the sticky threads and follow the links to a model identifier, it will help to know the exact model for the future and we can advise you on anyworthwhile mods too.

The exup increases the back pressure at low revs producing more torque. If you disconect it, replace it or wire it open the bike will get a bit gutless low downso it's best to keep it standard.