WD B40 Oil Problem

[gpo746]

Hi Everyone, I have a WDB40 and have had it laid up for 6 months , Started second kick as always and I ALWAYS check oil flow , this time nothing out of the return. I stopped the bike after 30 seconds or so and checked oil delivery by removing the flow pipe from the tank and putting a small funnel in it with oil from the bike, I turned the bike over on kickstart with ignition off, plug out and observed that the oil level did indeed go down so I was confident there was delivery but still nothing on the return side .
I drained the sump where I found about 1/2 coffee mug full of oil, The remote Vokes filter was full of oil too. Anyone have any ideas please?

[rhyatt]

you didn't have it running for those few seconds with the bike on the side stand???

if so, then the pick up pipe for the scavenge is further away from the oil, try it on the centre stand or just sit on it until the pump picks up the oil,

you know you are feeding the engine anyway

[gpo746]

Thanks for the reply, no it was started up on the centerstand. I did remove the sump plate and check the ball bearing up the pick up tube was free and seating back down ok and all seems well there . I am hoping there hasn't been a pump issue  . Thought it best to run the problem past people in the forum to see if I am missing something

[Tigerfeet]

I wonder if you could disconnect the return oil line from the metal pipe coming out of the engine. And then kick over with the plug out until bored...   Just to rule out a blockage in the rubber pipe and upwards?

[Tigerfeet]

I was trying to think of a way of checking the scavenge side of my C15 - and came up with this. Seems perfect. Oil was sucked up the pipe (great), and didn't drain back down (also great).
I just span the back wheel a couple of times in top with the plug out.  (Kick start pawl being welded...)
Maybe it would help in your investigations?

[gpo746]

Yes, that looks an excellent way of checking to see if the pump is scavenging . I will bear that in mind thankyou  .

I would still like to hear other ideas on what the problem could be though..

[gpo746]

Just wondered if the pump can deliver oil but not scavenge at the same time?
Does anyone think the pump is broken or am I missing something?

[rhyatt]

The innards of the pump would have to be seriously shot to do that I think.
The sets of gears are interlocked , driving each other.
Try the clear pipe trick sucking up from a tray of oil.
I'd pull the plug out, put it in 2nd or 3rd gear and rotate the back wheel and see if it lifts oil.
These gear pumps are very good at moving oil , so need to have oil in them to enable them to move more oil.
This is why the ball bearing is in the top end of the scavenge pipe to keep the pump full of oil and not let the scavenge side run back into the sump

[gpo746]

I see, thanks for that . I will give it a whirl and see if she lifts oil .