Motorcycle Repair: Gpz900R with ZX10 carbs, induction side, air screws

Question
Hi,
  I recently fitted ZX10 carbs to my Gpz900R, the Gpz is a late model and so has a restricted air box and had smaller main jets and different needles.

I have removed the airbox restrictor and fitted zx10 carbs which incidentally have the same size main jet as the early unrestricted Gpz900R (135).

The mid and top end performance is fantastic with these carbs but the engine wont idle and runs lumpy below 2500 rpm.

I balanced the carbs the other day but that made no difference, they weren't out by much anyway.

If i turn in the idle screw in so the bike ticks over, as soon as you touch the throttle the revs shoot up and stay there even when you shut off the throttle, then slowly drop back down.

The cables are free, the float heights are set correctly, the slides are free, there are no air leaks on the induction side, the pilot air screws are set to 2.5 turns out, the carbs are balanced, looking at the spark plug the mixture is ok.

What's wrong ?

cheers.  

Answer
i know you say the carbs are free and easy you might want to change out the throttle line to the carbs i know it sounds funny but in the 23 years of my experience i have seen it lots of time. try this and e-mail me back i will look at my micro-film questions i have stored in the last 23 somewhat years to help you on this one o.k
dont forget to mleave feedback on my answers ok , but i will get you going 1 thing at a time good luckk and keep riding.

                            mitch kruszynsky