Anyway to test an oil pump?

[Nessism]

The oil pump design is almost foolproof so my guess is the problem relates to the wiring or maybe the sensor itself. What about performing some continuity checks on the switch, both with the engine running and without? It's possible the oil pressure regulator spring is stuck allowing oil to bypass but this seems remote unless there is a lot of crud in the crankcase. Dropping the oil pan would tell the story on this.

[JEEPRUSTY]

Could the filter screen being plugged cause this to happen?

The machine should definitley sound like a sewing machine with no oil getting to the top end via the top oilers.

Does the oil look clean at least?

[tkent02]

You guys are missing the point. Let's say there is a tiny bit of pressure, not much due to a blockage, broken spring in the pressure regulator, o ring blown out or whatever. Just because the cam hasn't destroyed it's bearing yet doesn't mean it's not going to, or that it's OK to run with such low pressure.

He said the oil comes out the oil pressure port when the engine runs, but not under much pressure. Sounds like a blockage before the pump or a leak after the pump to me.

Whatever it is he needs to find it.

I loaned my first MG to a new guy on the ship one night. He brought it back saying the oil light had a problem, it keeps coming on. It never occurred to him it might be a real pressure problem, it had a leak in the oil pipe alongside the head. That was the beginning of the end for that engine.

Edit, still don't have a diagram of this oil system, anyone care to post one?
Cliff, your link to the '83 GS550 service manual in the website won't work, been trying for three days.

[spyug]

Thanks for the continued interest guys. I'll recap as best I can.

The oil was changed with a new filter.
I did no other work to the engine.
There were no leaks anywhere on the engine.
The engine made no weird noises and ran and shifted smoothly. It was on this test ride of less than 5 minutes that I noticed the OP light and sidestand light stayed on.
I pulled the pan and have just removed the clutch cover and see no evidence of sludge or bits of metal.
The oil filter screen was clean with not buildup.
The o-rings ( 2 of them) were in place
We checked that the sensor will trigger with 3 or 4 pounds of airpressure and the lights will go off.
I was using the sensor hole on the top of the engine case (just under the carbs) to screw in my OP gauge. I did buy and try a new sensor and tested it to make sure it worked...made no difference.

It should be the test plug just under the ignitor cover.

I'm confused ignitor cover or pick-up coil cover? I didn't know, I'll have to look.

Oil pressure regulator, is that the device fixed to the oil pan, kind of a chrome tube? I'll need to check the fisches as the manual is unclear.

I've been working on trying to take the clutch basket out so I can pull the pump but am now hung up for want of a 31mm socket to remove the nut. I figure I've gone this far I might as well have a close look at it.

Its quite annoying to not be able to figure this out.

Thanks for staying with me guys.
Cheers,
Spyug

[tkent02]

The oil was changed with a new filter.
I did no other work to the engine.

Did it have normal oil pressure before you did this?
Did the oil pressure ever work correctly that you know of on this engine?


Spyug, Do you have a diagram of the oil system?

[tkent02]

OK got the manual finally, not a very good diagram. Looks like there are several O rings in the oil pan and other places which if they are failed would lead to low oil pressure such as you have. They would leak the pressurized oil out into the crankcase, so no external leaks, just not much pressure.
Enough to not have done any damage so far, hopefully.

[spyug]

I don't know that the oil pressure worked properly as I got the bike non running. The carbs were gunked so as soon as I could I switched them for a clean set I had off the parts bike. When first fired up I don't recall seeing the OP light stay on but I won't swear to it as I was probably a bit distracted.

Does this help any:

As I'm stuck with the clutch hub nut and lacking a socket, I will next scope out the head and see what we have there.

When dealing with the seller I didn't get any bad vibes and as an aircraft mechanic I thought he would have kept things in good working order. He didn't mention anything but in thinking about it more I'm now starting to wonder. It was priced way less than I figured it should be and perhaps I sucked myself in thinking how fortunate I was to get a great score. I hope I'm wrong as he seemed like an honest guy.

I'll keep chipping away.

Cheers all,
spyug

[JEEPRUSTY]

Spyug

I do know that witht he top oilers removed that the oil will shoot up a couple of feet in the air. So your dribbleage is odd unless the pressure port is on the circuit feeding the crank bearings.

Had this happen when I forgot to connect the hoses.
So even in ideal condition oil will pump in high volumes.

[tkent02]

Did you use the correct oil filter? Did it seem to fit properly? After the pump the oil goes through a passage in the oil pan. I bet there are O rings there. They could be failed or not installed correctly. Does the oil pan look like it's been removed lately?

The oil pressure regulator could be broken, letting most of the pumped oil return to the sump without going to the engine.

There may be other o rings in that engine which could fail, and let the oil out without leaking externally.

[spyug]

I do know that witht he top oilers removed that the oil will shoot up a couple of feet in the air. So your dribbleage is odd unless the pressure port is on the circuit feeding the crank bearings

Well at an average pressure of say 55 psi it sure should shoot out like a geyser thats what really caught my attention.

At this point, I'm more convinced I have a busted or plugged pump as its the thing providing the pressure after all. I'm not ruling anything else out mind you but I'm having trouble wrapping my head around o-rings being a problem. Having said that, we do know how many problems they cause in carbs so maybe it would be best to change them at this point too.

Cheers,
spyug

[tkent02]

Look at it like this. Turn a garden hose on, slowly. No pressure in the hose. Stick you thumb over the end, to spray water. Now there is pressure in the hose. The oil system in the engine works like this. Take your thumb off, no more pressure.

[spyug]

Does the oil pan look like it's been removed lately

No, it looks like it had neve been off, same as the clutch cover.

I did use the right filter and it did go in no issues ( with a fresh cover gasket).

After the pump the oil goes through a passage in the oil pan. I bet there are O rings there

I thought the oil went up and out to the crank bearings and up to the head then back down into the sump. I'll check the pan for o-rings.

The oil pressure regulator could be broken, letting most of the pumped oil return to the sump without going to the engine.

Is there anyway of checking it? This is what gets me, If it is defective I likely wouldn't be able to tell and it could be the same thing with the oil pump and what prompted my original question. I feel like the only course of action seems to be replacing all the parts and o-rings in the hope that something sorts it out. This goes against my natural inquisitive nature of wanting to find a cause, however.

Thanks for the comments and suggestions.

Spyug

[JEEPRUSTY]

Are you checking the pressure at the spot indicated in the manual?
That may be a big factor in the whole mess. You may be masurunr a circuit that is recieving little oil pressure because of normal diversion.

I would check the OP at the place Suzuki said to.

[GregT]

Pull the pressure relief valve and check the spring is not broken.
When the valve is assembled (but out of the motor) it should be possible to push the ball off it's seating with a small screwdriver - and a fair amount of effort.

I struck a similar problem with a Kawasaki which had sat in storage for some time. The relief valve was the lowest point on the oil circuits and water had corroded the valve so badly it bypassed oil constantly.

[Mekanix]

the bolt just under the pickup cover is the oil pressure test port. that is where you will read maximum pressure.

the oil pressure regulator is that little thing sticking up from the sump pan.

get a 30mm axle socket from a garage or local parts shop.

i still think for the moment that your problem is to do with the sump pan or oring between the pan and case.

look at the manual page 153 on.
there is one page showing the sump cover with the regulator and o ring im talking about.

to test the regulator you need to take it out and put 78psi through it or just take it apart to see what the spring pressure is like. its strong usually.