carb problem?

Jerry Clair darkclarity2k at
Sat Aug 11 06:43:49 PDT 2007

I've all but given up. I replaced the jet and needle in the old carb and put it on the new bike. It ran but not quite right. vacuum leak or something so I put it the jetted
carbs back on to old Rockelle. Mid range increase and it runs very good.
I will finish the season like this.  Like Steve suggested, a close inspection of the valves train and compression test. Maybe just use it for parts. ie, brake parts, rear shock etc.
 Rockelle may be a tired bitch but she's a good bitch, if you catch my drift. I know her, even though she needs steering head bearings sometime soon. The main thing is, indy, here I come.!

David Beard <davidebeard at> wrote:        I'll check my kit tonight, but I believe the needle I used WAS the alternate needle. Let me double check that though.
 Yes, idle mixture screw is the one you described. 
 Do you have a shop manual for your GPZ? If so, there is a good description with pictures of the floats and how to measure/adjust them. Still, I wouldn't touch them at this point. Wait and see how the bike runs with the proper needle settings.
 Make sure that the rubber diaphragm lip is seated in the groove before putting on the top cap. This can cause problems as well.
 Jerry Clair wrote: I used the needle NOT marked Alternate. They have a more even taper.
 (The ALT set has like a step in it) So, I guess the normal set would
 appear fatter. 
 The idle mixture screw? -is it located bottom center, just ahead of the
 bowls and inside a boss? Is it sometimes called the pilot screw?
 I have the set at 2.5 turns. When I got the bike it was set at 3 turns.
  I'll increase to 3 tonight also. (then maybe the choke can be eased off too)
 I want to leave the floats alone because I don't understand what retains
 that jet and don't want to it f*ck up .  I really hope the previous owner
 left them alone too. 
   David Beard <davidebeard at> wrote:         Yeah, with the clip in third groove and a washer under it, your midrange is going to be pretty rich. Where are your idle mixture screws set? You did use the fater set of needles, right?
 As long as your float valves and seats are clean, I doubt they are sticking. If you bump the floats hard enough, it's possible to change the float levels. You can check these if you continue to have problems but I wouldn't worry about that just yet. Try the settings I gave you first and see how she runs.
 Jerry Clair wrote:     I use the 138s, nut used the 3rd groove and use 1 washer below and 2 above.
 2 washers feels sloppy snd I fear a sticking float.
 I try your set up tomorrow. 
       David Beard <davidebeard at> wrote:                 Hey Jerry,
     You will need to install the 138 main jets. Install the fatter of the two sets of needles that came in the jet kit with the circlip in the second groove from the top. Place a couple of the tiny washers over the circlip as spacers to keep the needles from moving up and down too much when you reinstall them. When you put the plastic "cup" back over the top of the needles, make sure you don't block the little hole in the bottom of the slide. If you still have the stock 35 idle jets, turn your idle mixture screws to 3 turns out from seated as a starting point. You may need to fine tune them later. Reinstall the carbs with the K&N pod filters and put the bike back together. This setup should be very close to perfect with your V&H exhaust. Once you get everything setup like this, let me know how it's running.
 Dave B
 Jerry Clair wrote:         Dave
 I got the Kit today, I'll need your number again, :)
           David Beard <davidebeard at> wrote:                                              

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