KZ750/4 Carb ?'s

Hello,
I have a 1980 KZ750H 4cyl. with cv Keihin carbs. Open pod filters, 4/1 exhaust.
Is there suppose to be 2 lift holes in each Slide?
And if there is should I drill out both when installing jet kit? Also, where could I find replacement primary mains for these other than the dealer?

Thank You in advance,
Paul

To rejet for pods/pipes, the primary main jets have more effect on your mid-range than the jet needles do on this carb. This makes a jet kit an especially bad idea... We have had good luck rejetting these carburetors using Keihin parts and not using jet kits. There are TWO versions of the CV34. Depending on which jet needle you find in the carb, will dictate how it needs to be rejetted. There is a N01A jet needle version of the carb. Use a #140 Keihin secondary main and #70 primary main jet. Leave the jet needle and slide alone. The jet needle/needle jet on this version of the CV34 and primary main jet (#62) are fairly lean.

The other type of CV34 was used on later models using this carb and the mid-range was far richer. It used a N100 jet needle. The mid-range was richened by use of a #68 primary main jet. The main jet was relatively small #92. The best way to rejet this carb for pods/pipes is to leave the jet needle alone and leave the primary main alone and use a #130 main jet.

Last, as memory serves, there is only one hole in the bottom of the slide to relieve pressure. We have never noted much difference drilling these holes in the bottom of the slide as far as throttle response goes but it likely doesn't do much harm. Use a 1/8" drill bit.

I have gotten the larger secondary mains from Z1 enterprises.
www.z1enterprises.com/SearchResult.aspx?...True&KeyWords=keihin
Hav'nt needed to replace the smaller primary and hav'nt noticed them on Jeffs site either. Likely he would have them if I phoned.
I use the 135 & 62

Thank You Very much for the awesome replies.


I Have N10A needles so I should put them back in.
It had 65 primary jets in it.
Where can I find/buy the 70's?
I hadn't seen 2 holes in slides before and didn't think it was right, so I will epoxy one closed.
I have the dyno 136 sec. mains in don't know what that = in Keihin jet size, will get some 140's.


I aquired the bike in poor shape and don't know what had been changed but the carbs had been cobbed pretty bad. Bowls were glued on,some jets were missing completely, mikuni jets wedged in some passages etc.
So I am trying to get it good again.
The po gave me a new dynojet kit he had for it but never installed, so at least I didn't buy it for nothing.

Thank you again.