Oil pump

Hi all,I have a 83 kz750 l3.Did a oil pressure test and gauge didn't even move so we thought the gauge was bad and disconnected gauge and turned engine over,no oil came out.The mechanic helping wrenched at kawa in 70s and 80s.He said oil pump / pressure release valve or blockage of oil passage. I removed oil pan the pressure release was not stuck open or closed.The oil pump appears to function OK,did not inspect inside of pump.I held hand over pump screen and with help turned engine over(plug wires off).I could feel some very slight suction.Is there a better way to test pump I know I can check tolerance between pump rotors .How much suction should be felt?oh forgot to mention,this is a fresh top end and the oil light stays on.No problem before rebuild but did find some little rocks in oil pan I'm guessing rocks were around studs,and fell in during disassemble.

Take the plate off the pump and inspect it.
Steve

And maybe polish it with very very fine wet-dry paper.

G-Force wrote: Hi all,I have a 83 kz750 l3.Did a oil pressure test and gauge didn't even move so we thought the gauge was bad and disconnected gauge and turned engine over,no oil came out.The mechanic helping wrenched at kawa in 70s and 80s.He said oil pump / pressure release valve or blockage of oil passage. I removed oil pan the pressure release was not stuck open or closed.The oil pump appears to function OK,did not inspect inside of pump.I held hand over pump screen and with help turned engine over(plug wires off).I could feel some very slight suction.Is there a better way to test pump I know I can check tolerance between pump rotors .How much suction should be felt?oh forgot to mention,this is a fresh top end and the oil light stays on.No problem before rebuild but did find some little rocks in oil pan I'm guessing rocks were around studs,and fell in during disassemble.

When I rebuilt my 750B, it had about 72,000 miles. I assumed the pump would be worn so I ordered a new rotor...... when I checked the wear, there was none. It measured as new. Pros told me that KZ pumps rarely wear unless severely abused or dirty oil run a lot.

If you show no pressure and have the oil light on, that is a worry. If it was OK before the rebuild, maybe some crap like gasket debris or dirt got into a passage?

I might try something like: pull the spark plugs. Fill the engine with light oil (you can thin out some motor oil with mineral spirits) and try to pump it through using the kick starter. You should see oil shooting out the hole the oil pressure sensor screws into.

I had a similar problem but what happened was a cheap gasket kit had a normal o'ring for the oil gallery between the cases and the oil pump> the O'ring that Kawasaki uses is an oval type, therefore I had loss of pressure when hot.

Even a slightly damaged oil pump would still have some pressure and usually they don't just stop working it not pulled apart. I know this might be a bit cheeky but has the gear got the pin in the oil pump shaft that locks the gear??

Does the 750 have a normal or roller bearing on the crankshaft (roller should have a lower pressure than the flat bearing), basically with no pressure you could damage the big end bearings be careful.

When you pull the pan there are 3 tapered oil passage o rings and one large o ring that needs to be in place too

Thanks to all,if oil passage block happens would it cause over pressure and activate the pressure release valve and if while doing a pressure test it should not matter if there's blockage because pump is below top end or does pressure test, test oil exiting the top end?I'm hope it's something simple I don't want buy another head and base gasket. No

Not sure morning was off,but I did find one in the oil when I emptied my drain pan.Would missing o ring cause pressure loss?

Yes.
Steve

swest wrote: Yes.
Steve

ditto, yes it would and make sure they are the proper O'rings

Finally home from.after further inspection all o rings were in place but I notice that I installed oil filter wrong. I had the spring under the filter pan.Could that be causing my oil pressure problem.

It shouldn't.
Steve