Piston clearence spec

  • DoctoRot
  • DoctoRot's Avatar Topic Author
  • Offline
  • Sustaining Member
  • Sustaining Member
    Registered
  • Oh, the usual... I bowl, I drive around...
  • Posts: 2576
  • Thanks: 732

Piston clearence spec

19 Apr 2021 22:18 - 19 Apr 2021 22:28
#847074
No eBay APP ID and/or Cert ID defined in Kunena configurationI bought a set of these 1mm overbore KZ750 twin pistons. The manufacturer states piston clearance is  .025mm measured on the coating. This seems really tight, especially for an air cooled bike, although they are cast pistons and this is measured on the coating. Factory clearance spec is .043-.070mm.

I did read this on the the translated page
"In connection with an installation clearance reduced by approx. 0.025 mm (possible due to the MOS2 coating), this results in the best possible and desirable smoothness in connection with the highest operational reliability and the lowest oil consumption!"

Am I worried about something that I shouldn't be? I don't really know much about this coating


 
'78 1000 Long Term Project
 '80 750G
 750 Twin Big Bore Track Bike
Last edit: 19 Apr 2021 22:28 by DoctoRot.

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

  • Highway Magician
  • Highway Magician's Avatar
  • Offline
  • User
  • User
    Registered
  • Posts: 80
  • Thanks: 33

Re: Piston clearence spec

20 Apr 2021 08:30 - 20 Apr 2021 08:31
#847085
If you trust the translation, go with it.  It's either MOS2 coating or abradable powder coating on them. 

The extra coating is meant to wear off and allow the piston to fit the cylinder as tightly as possible, after break-in.
Motorcycle builder since 1973. Master Tech. Current bike: 1982 GPZ1100B2.
Last edit: 20 Apr 2021 08:31 by Highway Magician.

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

Moderators: Street Fighter LTD
Powered by Kunena Forum