Tired oil pressure switch ?

[Big Fluff]

Riding (giving it some) along today, everything's going fine, heavy braking from 140 for the roundabout, exit left, gently through the box and notice my oil light on
Kill the motor, pull over and think shit.
Fires it back up again, ticks over, no nasty noises at all, in fact sweet as a nut, oil light still on.
Oil level is spot on, no 'heavy breathing' from the crankcase. Leave it 10 mins, fire it back up and the oil light goes out.
When I stripped and built the motor during the restoration, the strainer was and is as clean as a whistle.
I'm running the turbo motor on 20W/50 mineral oil.
Bearing in mind that the oil pressure switch is 29 years old, do they fail.? Has anyone else encountered this problem

Thanks, Will

[Hack]

It could be the switch but it could also be the old "air lock in the oil pump" although this usually occurs under heavy acceleration.

I'm sure someone will post all the pictures with the KHI recommended mod's etc.

[Russ]

oil pressure on old Zeds doesn't run high anyway 3-4 psi. only. This is because of the way the bike is built ie big roller bearings on the main journals instead of the now more common white metal bearings which require a much higher pressure altogether. You thrash your bike the oil gets hot and thins out a bit and you will sustain a marginal loss in oil pressure. 2+2 you might say. You may have some wear in your oil pump which wont help. Your oil pressure switch may be set a little light. Try filling it with the best oil Silkoline 4t semi synthetic and see wot happens.

[Big Fluff]

Thanks Russ, though I'd be surprised if there's any wear in the pump as the bike has only done 1600 genuine miles
I've tried semi 4T already, and the oil light flickered then.
Maybe I should just go ahead and fit a new one anyway, just for piece of mind.

[FOZ1A]

Under heavy braking and acceleration,the oil flows back and forth in the sump.Debbens used to sell a baffle that fits in the sump to stop this,maybe they can advise where to get it.

Foz

[Big Fluff]

I don't think oil surge is the problem here, as the oil light stays on whilst stationary. Thanks all the same.

[Hack]

If I remember correctly, once air has entered the pump (due to the surge) it can't always prime itself, even when the the oil level returns to normal around the strainer.

There were a number of mod's, one was the sump baffle as mentioned by Foz and another required drilling a small hole in the pump body to release the air.

I can't find the drawing of this at the moment but I have seen it posted on here before, someone will have it.

[Pigford]

BF, they do play up time to time

I had same on my Zed last year, and panicked, same as you

Limped home.... changed switch &....

CURED

[floydsz1]

I have a spare switch you can try if you want. Its one iv'e had for a few years, as far as i know its ok. If you want to try it pm me your address.

[Rich]

When you rebuilt the engine did you re-use the o-ring that goes between the sump and bottom crankcase (PN 92055-052).
If you did and the oil light comes on at tickover when the engine is hot put a new one in.
The thickness differences of the new gasket / compressed o-ring is probably just enough to allow oil to bypass the o-ring when it becomes hot.

[z1000Chris]

The way to determine if its lack of oil pressure or its the switch is to fit an oil pressure gauge in the side of the block ( 14mm blanking plug ) or if a gauge is not available quickley remove the blanking plug when the light is on to see if any oil comes out ( it is only a low pressure system so oil wont pour everywhere ). I had an oil pressure oil problem with a Z1b, I checked everything, it turned out to be the pump, even though it was in tolerance, it must have been a porous casing, mind you it had done a few miles, anyway good luck z1000chris

[Big Fluff]

Thanks everyone, some good points there, and yes, I did reuse the O-ring on the sump.

Hack - That's a good theory there mate, like you say, the pump may take time to prime itself after drawing air.

Floyd - Thanks for the offer of the switch mate, but as I'll be ordering a new O-ring from Z Power, I may aswell get an oil pressure switch too. You keep it mate, ya' never know when you just might need it. Thanks though.

I'll also see what I can do with regards to baffling the sump when it's off to fit the new O-ring.

Cheers guys, Will

[Pigford]

BF, I have a spare NEW oil seal if you want it
pm me

[Pigford]

Will, posted it this morning, before midday, so hopefully be with you Monday

[Rich]

My money is on the o-ring. Being a tight **** I reused an old o-ring, it was the thickest one I had but when I changed it - after swapping switch, disconnecting oil cooler, re-machining cooler take-off it cured the problem. With the new gasket and the old ring oil would bypass the ring instead of going through the system.