Oil Light at low revs on a KZ1000J

Hi:

Recently bought a 1981 KZ1000J. But it has a problem that maybe a member can throw some light at.

The bike is standard except for K&N filter pods. The engine oil light has just started to come on at low revs after about fifteen minutes of riding. I shut the bike down and changed the oil to castrol GTX 20-50W and the bike seemed fine again until I've had it on the highway for a short time then pulled up at a stop light and the light came on again. It goes off as soon as the revs increase a little. The engine is quite hot but there's no bluing on the headers? New filter, new oil and the plugs are normal. One expert says that the jets are too small and the oil gets too hot from the lean burn at highway speeds. Another says the screen may be blocked or the pump may be damaged. Any ideas most welcome.
Viv, Ottawa

Post edited by: vrdw, at: 2007/04/23 04:49

Hi Welcome to the site.

My bike, and I hear that KZ's in general, operate on a low oil pressure system... in the order of 5 to 8 lbpsi. So low pressure in general is not a problem. However, what you need to know is whether or not your pressure is actually below these low levels or not.

If you believe that your pressure is really OK then your oil pressure sensor needs to be changed. On mine, its located on the right hand side, under the timing cover and under the points plate. Yours may be the same... fairly easy to change really.

However, if you believe that your pressure is not OK, which would be my first guess, then you might suspect the oil pressure regulator. On mine it is a simple blow-by or shunt or relief valve that dumps oil back into the oil pan when the pressure exceeds the maximum specified value. The spring inside could be weak for example. I'm assuming here that your keeping the idle speed in the 950 to 1050 rpm range which I think I remember seeing in the owners manual somewhere. Any ways, check this first and adjust upward if necessary... I wouldn't adjust down right now since it could damage your engine.

Apparently, pressure gauges at these relatively low levels are not the most common type available. But you could search around your UAP or other automotive parts supplier. You could screw it in temporarily instead of the pressure sensor to get more facts. The tread is metric so bring the sensor with you to get a matching connection setup.

Hope this helps. Best of success and have a great, if short, riding season.

Post edited by: bill_wilcox100, at: 2007/04/23 05:29

Bill,

isn't there an oilway plug on the J on the RHS just behind the engine block into which an external pressure gauge could be screwd for test purposes without disturbing anything else?

Also have a look at the UK site and trawl thru using their search function


www.z1ownersclub.co.uk/forum/viewtopic.p...ghlight=oil+pressure

Post edited by: Kiwiz, at: 2007/04/23 15:44

I guess I'll have to let one of the j pros tackel that. While there are similarities there are also some important differences between my machine and vrdw's.

Are there any j owners that can help vrdw out?

Hello had the same problem with my Z1000. I double checked oil pressure with an oil pressure gauge and it read fine. The problem was the oil light switch, when I opened it up, it had tiny metallic debris shorting out the contacts.