To re-jet or not to re-jet, BS34 Z1000J

So I've been looking at my carbs for the last couple of weeks, well I partly dissasembled them to check jets and such.

It's the BS34 CV Mikuni carbs (I presume) on an European (K)Z1000J(3) meaning it's from -83.

One of the prevoius owners have put a 4-1 Termigioni exhaust on, and judging from the apperences of that exhaust it was done a while back, since it's a heavy 1-piece welded thing. It's been run on what I asume is the original main jets, 125:s, and orginial aribox set up. It seems the needle, which I think (?) stock comes set up on the next highest setting (the next leanest position)has been changed to the next lowest setting.

For the first part of the upcoming season I'm planning on running the bike with the airbox, and maybe a month or two in changing to an pod filter set up with everything that it means for carb settings/mods/jets.

But for the while beeing I'm going with the airbox, but I'm thinking of putting an K&N filter down in the airbox and maybe putting the needle on the middle setting and maybe putting in 130 mains instead of the current 125's? It's this I would like some comments on, I'm about to order some jets, and some hoses for the airbox-to-carb, just gonna check my valve clerances and see if I need some new shims for some of the valves.

Thankfull for any thoughts or input about this.

Best regards,
Otto Sandstrom

Would suggest plug readings immediately following high speed throttle chop before arbitrarily increasing main jet size.

Good Fortune!

The plugs looks ok now, but I don't know what kind of riding the bike have seen, maybe most low- and mid range.

I tink I'll order som diffrent jets at Z1 enterprises so have can experiment witht hem when I can get the Zed out of the shed again, the jets are only around 1 Euro a piece, so I could order some diffrent ones in the range of 127.5 and upwards.

/Otto