Tired oil pressure switch ?

[Big Fluff]

Firstly I replaced the O-rings in the sump, along with a new filter and fresh mineral oil. Same outcome, lazy flickering and stays on after a good thrashing
By the way, the tickover is set at 1500rpm, drawthrough turbo bikes seem happier at this anyway.

However, when I came to replace the oil pressure switch, I did notice that even with a socket still in place on top of the switch, I had to ratchet it out almost all the way, highlighting that the threads were quite tight.
The spring pressure difference between the one taken out and the one given to me by Floydsz1 were very obvious indeed.... in that the old one had much more resistance.
When I fitted the replacement, I noticed that it could be run all the way into the housing by hand, and without any resistance at all..... much better
On start up the oil light now goes out immediately, and after a good thrash everything seems fine.
I'm putting it down to either the wrong switch fitted or it was faulty in one form or another. It's a bit puzzling why it was so tight on the threads though It looks identical in all respects
I know it would have been easier to replace the switch first, but I wanted piece of mind that the sump to crankcase O-rings have been replaced aswell.

Thanks to both Floydsz1 and Pigford for their kind donations.

Thanks, Will.

[Pasc]

Will, I'm wondering that if at some time in a previous life someone had fitted an oil pressure switch from a shell bearing crank engine (z650, z750 perhaps). These shell bearing cranks as you probably know run a much higher oil pressure than the roller bearing cranks (6 or 7 psi if I remember). If the switches are psi graded maybe your low pi engine didn't have the grunt to open the high pressure switch.
Just a guess and if all the switches are the same then it blows this theory out of the water.

[floydsz1]

Hi Will
Glad you got it sorted,

peter.