GS 750 Oil pump

[andyp62]

Hi
Has anyone had problems with oil circulation ?,i have a 1977 GS750B which is having oil circulation problems, i have the sump ,strainer, clutch and pump off but i dont see any real issues, if anyone has had similar issues and can advise where to look next or closer inspection without taking the engine out i would be grateful. Engine turns over ok i wondered if there was any checks i can do with the engine in situ.
thanks in anticipation
Andy
( any recomendations for best oil would be apreciated)

[Brendan W]

What is the circulation problem, light staying on, dry at the top end?
Was the clutch nut lose?
Is the filter ok?
A lot of us use 15W40 diesel spec oils for the better high load additive package.

[andyp62]

hi
the light is staying on, i have taken the cam cover off and it does seem very dry, the clutch nut was reasonably tight but to be honest i expected it to be tighter, the filter did not look over bad but im not 100 percent sure of it, the bike had not run for quite a while, maybe 18 months

[Brendan W]

Did you run it 18 months ago or was this the previous owners story?
Have a look at the back of the clutch hub where it engages the pump drive dogs.
You are looking for a ring of bright metal where the pump drive was out of engagement and dragging on the hub.

[hampshirehog]

Try disconnecting the wire from the pressure switch - it could be chafed and shorting out somewhere. Very unusual for your bike to suffer from low oil pressure.

[TeamDar]

There is a 17mm hex plug just above and slightly behind the points/ignition cover. This plugs the oil gallery that runs behind the cylinders. With the engine idling, loosen this plug enough to remove it and expect a good stream of oil to squirt out. Immediately shut the motor off or replace the plug before you make a huge mess. This test will verify if you have an oil pressure problem or just a sending unit/ wiring issue. Dar

[allojohn]

Stupid question I know but are you certain your oil level is good?

[andyp62]

i did wonder if the sight glass was maybe not clear but yes it was full of oil

[andyp62]

i will try that as soon as i put the sump, clutch and filter back on, thanks

[andyp62]

will check that thanks

[andyp62]

i have owned the bike for about 15 years and it has never given me any trouble other than one coil failing, it just sat in the garage as i was using other bikes, it was when i decided to put it back on the road that the problem started, the engine reved ok at first but then it seemed to be labouring and not revving cleanly.I have the clutch off so will check the drive as you suggest