No Oil Circulation

[Winter]

So after getting the timing squared and getting my '65 160 to kick over reliably, I took a look under the covers to see if there were any oil issues.
There wan't a sign of oil in the valve bays or in the upper bevel set. Also, when I opened the banjo bolts on the shaft cover, no oil either.

I have since topped it up to the prescibed 2+ Litres (2.5 quarts) and I did check the oil pump (when turning the key I could see oil bubbling up in the cover) so something is moving, just not up to the head.

I have checked the gaskets to see that they have open ports for the oil to return in both the upper and lower positions of the shaft. At the risk of doing serious damage after a long rebuild, I'm wondering if it's just a volume issue and the old girl needs all 2.5 quarts to make the pump function properly.

Any ideas would be appreciated.

All the Best,
Andrew

[Dave450]

I take it the engine started and ran, since you said you got it to kick over reliably. You need to investigate and hopefully you haven't run it long enough to scuff the cam lobes and rocker pads. The oil pump should suck oil from the sump with two litres. Do not start the engine again until you have discovered the problem.

You saw no oil at all? It takes quite a few revolutions from a fresh rebuild for oil to pump up into the cam box, but it is vital to check this. As you turn the engine over with the kickstarter, plug out and valve covers and triangular bevel cover off, if everything is working as it should, oil will eventually flow through the cam lobes and if you have a jet at the bevel end of the camshaft, it will show there as well. I can't remember exactly how long it takes but probably about 30 seconds of cranking or less.

Remove the timing cover and using an oil can, pump oil through the oil gallery at the top of the timing chest. If the gallery is free, oil will travel up through the jet in the cylinder and then into the camshaft from the drive side of the engine and will exit from each cam lobe. If you cannot pump oil from the timing chest to the camshaft with an oil can, you have a blockage somewhere, and you need to find it.

If you can pump oil up into the head from the timing chest, it means the gallery is unblocked but you have a problem with the oil pump drive or the pump itself. You need to check both. Have you had the pump apart and did you re-assemble it correctly?

If the engine has been run with no oil to the head for any length of time, you will need to remove the rockers to see if there is any damage to their surfaces and to the cam lobes. If only run for a few seconds, and you lubed everything well at assembly, you may have escaped damage. How long did you run the engine?

[Winter]

Well, after pulling the motor, lifting the head, slipping off the jug and using a flexi wire handled tube brush, compressed air and a syringe of oil, voila, fossilized sand, or whatever this thing is. It was lodged in the passage that runs from the timing chest to the other side of the cylinder.

Nasty, but after flushing the gallery with a little 30 weight I beleive I am back on track. Oil is flowing side to side and the pump is bubbling oil up in the timing cover.

Thanks Dave (450)

All the Best,
Andrew

[Winter]

it takes but probably about 30 seconds of cranking or less

About 12-15 cranks and oil was flowing out the center of the cam and being depostitted on the upper bevel gears. I believe that's a good sign.
As for the blockage, I found an additional piece of thin walled plastic tubing, black and very brittle. I can't imagine how that got into the mix.

Buttoned up and ready to go.

Best,
Andrew

[Dave450]

Good news, Andrew. I assume the rockers and cam are OK and that you are over the worst of it. That blockage was nasty indeed. I suggest that if you found that crap in your motor, flush the oil after a spin to get the engine up to temperature and have a look at it to see what else was in there. The mesh screen in the sump should prevent the big bits from getting in but smaller debris could still be circulating in the oil. Good luck!

[Nick]

Glad you found the hidden time-bomb. When i was rebuilding my 250 I discovered a cracked cylinder and purchased a used one to replace it. Got it cleaned and bored, and was in the process of installing it when it occurred to me to run a piece of wire up the oil hole where the O-ring goes. Horrors! The oil way was blocked by a hardened dollop of silicone sealer. So many pitfalls to be wary of when saving these old bikes....