Oil Pressure at Idle on KZ1000

Quick question on oil pressure. I have a gauge on my 79 KZ1000. When I'd start it the pressure was always a little above 2 and would hit about 8 or so when I revved it. After a ride today I noticed the pressure sitting at 0 at idle, and went up to 3 when I revved it. The manual says 2.8 at 3000 rpm, which was a relief, but is 0 at idle normal?

6 to 9

Make sure your gauge is correct by checking it against a known good gauge. Vibration will kill ANY gauge eventually.

Where is your gauge's oil line attached to the engine?

It's a VDO gauge right on the oil galley plug. I just installed the gauge recently. This is a project bike I am building, motor has 40K on it. This is my first 4 cyl bike so I'm still getting familiar with the norms. I've put maybe 30 miles on it since I got the bike road worthy, and seems to run pretty good. Thanks for the replies.

Oil choice can play on this, what are you running? Stay away from the 5-30w car stuff. Get a 15-40w or 20-50w, Rottela or Delo etc.

2wheeltom77 wrote: Quick question on oil pressure. I have a gauge on my 79 KZ1000. When I'd start it the pressure was always a little above 2 and would hit about 8 or so when I revved it. After a ride today I noticed the pressure sitting at 0 at idle, and went up to 3 when I revved it. The manual says 2.8 at 3000 rpm, which was a relief, but is 0 at idle normal?

Is the oil pressure dash light functional?
And if so, does it stay off at idle?

Good Fortune!

I completely rewired this bike to basics, no dash lights. Am running 10w-40 Val bike oil. I do have idle set a little above 1000 and am thinking maybe I need to bump it up. I sort of forgot twincam harleys are the same way, don't make any pressure if idle is set too low. With this kaw motor, it seems like the only problem areas would have to be from the pump itself, or possibly really worn cam bearings.

Thanks for the replies.

If the oil pressure switch is in position, and potentially functional although not wired into the bike's electrical circuitry, may use an ohmmeter to determine whether the oil pressure switch is being activated by oil pressure at idle rpm, regardless of whether the oil pressure switch is connected to any wires.

Knowing there's activation of the oil pressure switch at idle rpm would indicate at least some oil pressure .

Good Fortune!

Patton wrote: If the oil pressure switch is in position, and potentially functional although not wired into the bike's electrical circuitry, may use an ohmmeter to determine whether the oil pressure switch is being activated by oil pressure at idle rpm, regardless of whether the oil pressure switch is connected to any wires.

Knowing there's activation of the oil pressure switch at idle rpm would indicate at least some oil pressure .

Good Fortune!

You know what, that's a damn good idea. I'll give that a shot. Do you happen to know what psi the switch opens/closes?

Don't think anyone has mentioned this yet but bear in mind that the KZ engine does not have journal type crank bearings, it has roller bearings. Making a lot of oil pressure at low RPM's is not crucial. Getting a pressure reading denotes flow through the engine.

DiamondSkyBlue1000 wrote: Don't think anyone has mentioned this yet but bear in mind that the KZ engine does not have journal type crank bearings, it has roller bearings. Making a lot of oil pressure at low RPM's is not crucial. Getting a pressure reading denotes flow through the engine.

Yeah, and that was my thinking that the worn out cam bearings would be the only wear component that might cause low pressure, and that's a maybe based on my understanding of oil flow through the engine.

I took about a 30 mile ride this morning. Started out cruising at about 5 psi, then warmed up about 2.5 to 3 at 3000 rpm cruising. By the time I got home pressure was about 2 at 3000, but went up to 3 about 3700 rpm.

I let the motor cool off to about 120 degrees and firing it up. Needle bounced a little at idle and read 3 at 3000.

At this point I'm thinking either the pump is a little worn, or worst case something starting to clog the screen up. If it gets worse after a few more rides, I'll change the oil and filter again. Then I guess it's time to pull the pump.