I have decided to join and help Joe out because he is a lazy bastard and his bike isnt going to fix itself.

I compression tested both cylinders and they both read around 140psi which i thought was fine.
I pulled the carbs out and gave them a clean but they werent very dirty and the jets were clear.

When starting the bike the left cylinder takes a little longer to fire and when rev-ing the engine bogs down around 2000rpm, the rev gauge jumps around and the oil light flashes.

Im not familiar with NSRs (im a RGV owner) so i dont know where the rev gauge gets its signal from.

I didnt have a multimeter so wasnt able to check the battery under load.
My next plan will be swap the coils and plugs over and see if thats were the issue is.

Are there any common faults that give these symptoms? or other tips?

Thanks