[NMKawierider]

Using this converter, I get something a little different.  https://www.convertunits.com/from/kPa/to/PSI

@1500 RPM, 70-300 kPa is 10.1-43.5psi with the typical 180 being 26.10psi. Then @6000RPM, 350-550 kPa is 50.7-79.7psi with the typical 420 being 60.9psi

Besides, the low pressure switch closes somewhere just below 7psi so it can't fall below that and keep the light off. Just about any engine with a pressured oiling system if it falls below about 10psi...there's a problem.


I got this pressure data from page 1-6 because page 191 I believe must be in error. Can't have any zero oil pressure readings when running.

[bezerk1]

I noticed that too.  Is this a typo?  I can't imagine that 0 psi is an intentional design.

[bezerk1]

I figured it out.  The first digit in the table is off.  It's 70, 180 and, 300.  So minimum is 10.1 psi.

[glenlivet]

Now that makes sense, the digit after the word belongs in the next box. Good eye bezerk1, I was really tugging at the beard with that zero stuff.
Fresh eyes and all that.

But yeah, then where's his idle oil pressure dumping off to? Hmmm

[NMKawierider]

Now that makes sense, the digit after the word belongs in the next box. Good eye bezerk1, I was really tugging at the beard with that zero stuff.
Fresh eyes and all that.

But yeah, then where's his idle oil pressure dumping off to? Hmmm

I think it isn't even getting it..in that it looses it's prime because of air intrusion. I also think it's been going on long enough that the pump's rotor has become... effected..enough to finally drop the pressure enough for the switch to come on. Air is not the friend of high pressure hydraulic pumps.... and lower pressure oil pumps ...just takes longer...

[davidpaul]

Now that makes sense, the digit after the word belongs in the next box. Good eye bezerk1, I was really tugging at the beard with that zero stuff.
Fresh eyes and all that.

But yeah, then where's his idle oil pressure dumping off to? Hmmm

I think it isn't even getting it..in that it looses it's prime because of air intrusion. I also think it's been going on long enough that the pump's rotor has become... effected..enough to finally drop the pressure enough for the switch to come on. Air is not the friend of high pressure hydraulic pumps.... and lower pressure oil pumps ...just takes longer...

I'm going to start with the oil pump side, I still have the original as there's nothing wrong with it, I will update soon, thank you

[glenlivet]

Ever get the feeling this long distance diagnosing is like being a surgeon helping another through a procedure by phone, not able to see the patient but just advising based on how the patient probably should present if he were healthy? 
Of maybe like a veterinary surgeon with the benefit that at least you can't be bitten?

I wonder about this test: get a socket, extension and impact gun all ready to take out the oil drain plug (and a pan!) and start the engine long enough until it's doing its trick, then shut it off and IMMEDIATELY zing the drain plug out. If the oil comes out in a fat finger width stream, unimpeded then that suggests it's not cavitating at the pickup, for inadequate drain-back to the sump. If it trickles out then there's a smoking gun.
Ideas?

[NMKawierider]

I wonder about this test: get a socket, extension and impact gun all ready to take out the oil drain plug (and a pan!) and start the engine long enough until it's doing its trick, then shut it off and IMMEDIATELY zing the drain plug out. If the oil comes out in a fat finger width stream, unimpeded then that suggests it's not cavitating at the pickup, for inadequate drain-back to the sump. If it trickles out then there's a smoking gun.
Ideas?

Or..how about this: Have the pressure gauge hooked up and visible from the key. Have the engine off and sit long enough to ensure all oil has returned and equalized in the sump. Without touching the throttle start it watching that gauge. if it jumps up and stays in a normal range for a time..say 10+ seconds..then falls-off, to me that would indicate supply was depleted at the intake. But, if it did not build pressure from the start...or did only for a second or two, that would indicate to me aside from the intake being completely blocked..which to me would be impossible.., it either a breach on the intake track or a failed pump...or a leaking cap...or..even a cracked in the case...something that would cause it not to prime.


It is interesting to speculate but in the end, it would be nice to know what really is going on.

[glenlivet]

That ought to work too. Imagine, the old 300 Suzuki King Quad had a sight glass right in the side of the casings, you could just look in and see the sump oil level. 

[NMKawierider]

That ought to work too. Imagine, the old 300 Suzuki King Quad had a sight glass right in the side of the casings, you could just look in and see the sump oil level. 

Yeah..the good ol'days.

[davidpaul]

She's slow to drain, I always warm an engine before drain oil and she's still slow, I used to make a cardboard channel/shield to stop the oil shooting out over the plastic under tray, but last week when I changed the oil it didn't need it .

[glenlivet]

Slow to drain at the drain plug after it's been sitting long enough for the oil to settle in the sump?
What the devil is in that motor? (did somebody leave a paper towel or shop rag in there?)
That's just...
All I can think of that might cause slow draining of normal motor oil is that something is partially blocking the drain passage, and maybe the pickup too.

I remember a thread on a King Quad site where someone had oil pressure problems and it turned out that a rebuilder had gooped a gasket sealer all over and chunks of it had come loose.

Just throwing things around, here.

[Workhardplayhard]

I was going to suggest making sure the ball and spring are both present in the relief valve. But the slow to drain is puzzling. Did you pull the screen out while changing the oil? Was it clean? What did the filter look like? Was it collapsed?

[davidpaul]

I was going to suggest making sure the ball and spring are both present in the relief valve. But the slow to drain is puzzling. Did you pull the screen out while changing the oil? Was it clean? What did the filter look like? Was it collapsed?

It was a new valve when I rebuilt the engine, i don't belive the screen can be removed without splitting the engine cases,
the oil filter was fine.

[Workhardplayhard]

I was going to suggest making sure the ball and spring are both present in the relief valve. But the slow to drain is puzzling. Did you pull the screen out while changing the oil? Was it clean? What did the filter look like? Was it collapsed?

It was a new valve when I rebuilt the engine, i don't belive the screen can be removed without splitting the engine cases,
the oil filter was fine.

I have the 500 and the screen is in the same location as the drain plug. You just take out the 3 bolts around the drain plug and there it is. I was just assuming it was the same on yours. This is puzzling… nothing else is coming to mind as to what it could be. I truly hate to say, you may need to open it back up. Can you access the oil pump seal without splitting the case?