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Dry sump!

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K2-K6:
You should be able to see a schematic of the oil pump in Ash's manuals for the 750 .

It makes clear the flow pathways and has the "leak stopper valve" usually listed as #3 in my manual.

The whole lubrication schematic is there too, and worth a look.

Skoti:
That 'leak stopper valve' once stuck open on my CB750F1 and dumped all the oil from the oil tank into the sump.

I'd returned from a long run and checked the oil tank level the following morning and noticed it was empty, almost shit myself...

But It was easy enough to check the leak stopper in situ by removing the sump and the two 6mm screws on the oil pump leak stopper end cover.
The leak stopper bore had a slight ridge worn in it, presumably at the open position, so I dressed it up with fine wet and dry paper and reassembled it.
It's been OK for the last 5,000 miles or so.


BTW Johnny,
I don't think your sump should normally have as much as two litres of oil in it, but maybe some body who knows for sure will be along shortly to let us know the exact quantity.

 

K2-K6:
Generally the sump quantity would be less than 500ml and probably aggregated at around 300ml.

It's a general principle of any dry sump system that the scavenge pump capacity exceeds the pressure feed one, else it can't work. The oil tank would be depleated if you rode for a long time with all of the oil remaining in the sump eventually.

Johnny4428:
Thanks guys, interesting to learn a little about the lub system. Ran the bike again the day and quite sure there was movement within the oil tank. I was toying with the idea of fettling and running bike next year but too many unknowns! Want to fully restore to as near original as poss so drained oil this afternoon with the view to remove engine for complete strip down. Will post some pics of internals ad I go. Let the fun begin.

Trigger:
Always better to overhaul the oil pump on these old girls, just a few O'rings, a center seal, stopper valve and springs.
The way to check the oil is after a good ride. Pop it straight on the stand and see what level the oil is at. I always have the level about a 1/4 down on the line and if you over fill, it will spray over the rear tyre  :o

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