Z1 plunger replacement

  • Nessism
  • Nessism's Avatar
  • Offline
  • Sustaining Member
  • Sustaining Member
    Registered
  • Posts: 8206
  • Thanks: 3577

Re: Z1 plunger replacement

07 Sep 2026 15:19
#927353
I've seen a fair number of bent tips.  Put them in the lathe and spin them, and you will see the tip wobble.  I take a screwdriver and whack the tip with the handle until it spins straight.  It's hard to explain the process; it just sort of happens.

Please Log in or Create an account to join the conversation.

  • asphalt900
  • asphalt900's Avatar
  • Offline
  • Sustaining Member
  • Sustaining Member
    Registered
  • Posts: 1953
  • Thanks: 1314

Re: Z1 plunger replacement

08 Sep 2026 05:48
#927362
I still stand by exposure to the supply of those i have in hand, none bent. I can understand Zed's situation though, mailer from across the pond incorrectly packaged. And never desired proficiency in senders address ha. No fancy "V-blocks" needed, just chuck them up in a 3/8 drill and spin/watch behavior. A nominal casting opening on ALL VM carbs for tip is 2.3mm BTW. I'm sure bending "can" happen, just never have never ran across it.. Jim..do what You want for experimenting but Complete removal of existing plunger pad might create more issues then it solves. Think like of your endeavor like this. Say you did run across a 2mm ID X 7mm OD X 2ishmm CS, where is the pressure from casting hole/ledge going to seal? O-rings are of course round so seat in casting is going to "pinch" the inner radius..for a while..till that radius collapses. Buna-N is pretty soft, 50/70/90 duro, they all will eventually succumb to the sharp edge and collapse. Now installed height will change or lacking the function of shutting that petrol off. Think that one thru. Regarding the "Air" screws. I'm not familiar with Johns take on this, haven't talked to him in a while but I believe the taper was the same thru all the 4cyl and triples. Are You sure it wasn't just an aftermarket SPRING used that the coil bound before screw was fully seated? I had a minimum of 500 of these plunger pads cut out in Viton by Hanna Rubber here in Kansas City probably 20yrs ago. Thinking i did maybe 3 sets of carbs. Then we moved..can't find the little brown paper bag that was chuck full ha.      
The following user(s) said Thank You: sf4t7

Please Log in or Create an account to join the conversation.

  • Rolf1976_KZ900
  • Rolf1976_KZ900's Avatar
  • Offline
  • Sustaining Member
  • Sustaining Member
    Registered
  • Posts: 500
  • Thanks: 261

Re: Z1 plunger replacement

17 Oct 2026 03:34
#928571
Its now time soon to store the bike for winter. The last months the bike has not run well .What happens is that it soot the plugs in 5 minutes now even i middle of the summer. I tried everything to fix this ,but no luck so it got to be the hardened rubber on the plungers not sealing.
Zed i vould like you to fix the plungers if you have time this winter. Plase send me a PM with the details. I sent you a pm about 15 minutes ago before i found this tread. 

Please Log in or Create an account to join the conversation.

  • Rolf1976_KZ900
  • Rolf1976_KZ900's Avatar
  • Offline
  • Sustaining Member
  • Sustaining Member
    Registered
  • Posts: 500
  • Thanks: 261

Re: Z1 plunger replacement

17 Oct 2026 03:38
#928572
Update I just recieved your pm Zed thaks !

Please Log in or Create an account to join the conversation.

Moderators: Street Fighter LTD
Powered by Kunena Forum