Oil pressure gone!

[sharpeyie]

Hi guys.

Z1B. En route back from my first ’50-miles-plus' outing since engine rebuild, on Sunday last. Stopped for 10 minutes and oil warning light failed to go out when I restarted. Tried the obvious pressure switch wiring checks etc. Anyway, fast-forward to getting the thing back home and I happened to have a new switch in my spares which I installed tonight - no change.
Went on to check for traces of oil at the end of the oilway on the right side of the crankcases (above the ignition). Even with the engine runnning there was not a trace, would I be right in assuming there should be oil here?

If there is an obvious ‘by elimination' route I should follow here to finding out if the pump is buggered, I'd be grateful to know what it is. I don’t have an oil pressure gauge to hand but if that’s what is needed....... etc.

Thanks all.

[Al]

You should get a good flow of oil out of that plug on the RHS. Have you dropped the oil to see if there is anything obvious like its heavily emulsified of full of 'string'. String being polymer chains caused by contamination from another source or product. If the oil looks anything other than perfect; drop the filter and see if the surface is coated in anything. Again heavily emulsified oil may block it. If all looks good its pump out. Does the Z1B have a pressure relief valve in the oil filter centre fixing bolt? Late ones do but not sure about the earlies!
AL

[sharpeyie]

Right..... ok that makes sense I’ll check that. If I drain the filter first (leaving oil in the rest of sump) and then turn over the engine I’ll get a flow there right (at the filter drain plug if the pump is working at all)? Would that make sense too?

Thanks for coming back.

Stewart.

[Al]

You could do that and it would be useful but i would take the plugs out and turn it over by hand rather than start it. It will still move oil even at hand crank speed, just not very much, but enough to see. Does it have an oil cooler on it?
AL

[gray]

at the risk of sounding obvious, I assume the oil level was ok at the beginning of the ride and was still at the same level once the oil light came on.

[sharpeyie]

at the risk of sounding obvious, I assume the oil level was ok at the beginning of the ride and was still at the same level once the oil light came on.

Always worth asking - but yes.

[sharpeyie]

You could do that and it would be useful but i would take the plugs out and turn it over by hand rather than start it. It will still move oil even at hand crank speed, just not very much, but enough to see. Does it have an oil cooler on it?
AL

Ok thanks. No oil cooler.

[gray]

so there plenty of oil in it but no oil pressure .could be a worn oil pump ( if its drive gear wasn't engaged or broken the pump wouldn't have worked at all and you would have seized before 50 miles) or possibly you've missed out some of the O rings between the crank case halves that feeds high pressure oil to the pressure switch, the gallery then the head. You will be getting some flow to the head ( allowing it to run) but you will not be getting the expected pressure as some oil will be escaping the joint and returning to the sump ( so it still looks like its full of oil)

[DavidZ1R]

Yes sounds like one or more sump o rings missing or not correctly fitted

[sharpeyie]

Bit of an update and I’d like your thoughts guys.

I removed the filter and checked to see if the oil was being pumped into the filter chamber (which it is.) Took filter off the bolt/cover assembly and replaced cover without the filter. Oil light went out after about 10 seconds. Are we looking at the pump working but worn to the point of not delivering enough pressure potentially (not enough to deal with the filter) - is that feasible?

What kind of pressure should it be delivering - on the starter it was ‘oozing’ through the opening into the filter chamber, nothing more spectacular than that, would that seem about right or should it be more pronounced?
I know these are really subjective questions.


Rgds,
Stewart.

[gray]

someone who has fitted an oil pressure dial to the blanking plug at the oil gallery will be able to tell us what pressures they typically see.
Oil pumps don't fail for no reason - they're bathed in oil after all.
Looking back to when you did the rebuild in the first place - was it done due to a specific problem, or as a precaution? What mileage was on the engine? Was there a lot of debris on the oil strainer gauze? was there greyish or metallic goo coating the bottom of the sump? If you noticed the latter 2 situations, then the pump might have been drawing in contaminated oil and this could have led to internal pump wear. However if this was a relatively low mileage engine , stripped purely to refurbish the appearance of crankcases head and barrels (say) , and the strainer was clear and no goo in the sump the oil pump's probably OK

[zed1015]

someone who has fitted an oil pressure dial to the blanking plug at the oil gallery will be able to tell us what pressures they typically see.

They only kick out 3 to 5 psi when cold and next to nothing when hot.
The pumps are high volume low pressure.

[Al]

When you took the oil filter , bolt and cover off how much oil came out?
If it was 200cc and it came out in ten seconds then fine. If it was a litre or so and it kept dribbling for a minute plus, then the 'O' ring between sump and lower case is either missing or the wrong one (cross section ~ there are at least two different sizes).
When you turned it over with the filter out, did you witness oil issuing from the oil drilling or just see oil coming into a tray viewed from above? If its the latter answer for both you will have to take the sump off and have a look at the pump, its wheel, drive peg, 'E' clip, mounting and 'small chamfered 'O' ring and gasket etc.
The chamfer on the 'O' ring faces the pump.
You may be able to insert a thin feeler blade between the sump and botton crankcase inside the oil filter housing. If so then the 'O' ring needs looking at regardless of the fact that the gap closes up when you tighten the oil filter centre bolt.
I had a very similar thing earlier this year. In my case it was the oil cooler which was not passing oil, however; i did drop the pump twice and turned it over by hand sitting in the oil i had dropped and it pushes quite a bit. The pump works on flow and not pressure so expect volume not squirting. I assembled an oil pressure guage for the gallery end plug and got 12 PSI cold with brand new fresh oil at 2,000RPM and 1, 2 or 3 PSI hot after ten minutes at the same RPM rising to about 5 PSI max at about 4,000 RPM hot.
AL