pressure oil z1 900

Here's an excerpt from Dave Marsden's History of Z1 (Chapter 5 about the 1975 model):

LUBRICATION SYSTEM:

THERE HAD BEEN REPORTS ON EARLIER MODELS THAT THE OIL PRESSURE WARNING LIGHT HAD BEEN STAYING ON UNDER SEVERE ACCELERATION. THIS WAS PUT DOWN TO A SLIGHT DECREASE IN OIL PRESSURE ON SOME ENGINES. IT WAS ADVISED THAT THE OIL PRESSURE SWITCH SHOULD BE REMOVED AND THE SMALL HOLE IN THE SWITCH SHOULD BE RE-DRILLED TO ALLOW AIR TO ESCAPE MORE QUICKLY. IT WOULD SEEM THAT AERATION OF THE OIL HAD BEEN OCCURRING BY THE SUDDEN MOVEMENT UNDER ACCELERATION. HOWEVER, ON FURTHER INVESTIGATION, THE PROBLEM LAY IN THE OIL PUMP ITSELF. AIR WAS GETTING TRAPPED IN THE PUMP BODY AND KAWASAKI ADVISED DEALERS TO DRILL A SMALL DRAIN HOLE INTO THE PUMP TO ALLOW IT TO ESCAPE. THIS MODIFICATION WAS TO BE CARRIED OUT 'DISCREETLY' BY DEALERS BUT MANY WERE NOT TO IMPRESSED WITH THIS TIME CONSUMING SOLUTION. SPOILT BY THE LACK OF 'SPANNER' WORK THAT THE Z1 NORMALLY REQUIRED, DEALERS PRESSURISED THE FACTORY TO SORT THE PROBLEM OUT AT THEIR END.
KAWASAKI WERE NOT GOING TO LET THIS PROBLEM SPOIL THE 'BULLET PROOF' REPUTATION THAT THE Z1 MOTOR HAD EARNED ITSELF, SO THEY CHANGED THE OIL PUMP ON THE ENGINE ASSEMBLY LINE.
THE MODIFICATIONS INCLUDED A THICKER GASKET BETWEEN THE TWO PUMP HALVES AND A DIFFERENT OIL STRAINER. THE NEW STRAINER WAS NOW A PUSH IN FIT INSTEAD OF THE PREVIOUSLY SCREWED ON TYPE.
THE CHANGES ALSO REQUIRED A SLIGHTLY BIGGER SUMP PLATE TO BE FITTED.
NEW PART NUMBERS:
OIL PUMP 16082-059
SUMP PLATE 16110-003
STRAINER 16111-004


Good Fortune!

This link is on point, but text and images from the service bulletin are almost illegible.

Click here > www.tapatalk.com/groups/vjmc/kawasaki-z1...l-pressure-t224.html


Good Fortune!

lomolinom@libero.it wrote: thanks a lot but I also look for pictures of the hole in the oil pump

Hi lomolinom,
Our apologies. slmjim inadvertently duplicated the Service Bulletin attachments :blush: .

Z1BEBE will torment him appropriately .

Fixed in our above post, and the correct attachments are also posted below.

Good Ridin'
slmjim & Z1BEBE