Oil Pump Issues

[Anthony Duffield]

I suspect I have an issue with the oil pump on my Commander having found that that the gearbox oil level slowly increases. I have checked the pipes and connections as much as I can through the cover finding that all seems to be OK, perhaps its the pump shaft seal. Has anyone else had similar issues with their oil pump?

I have no records from the previous owner indicating that the pump has been renewed so would guess that it is original, the bike has covered 82000 miles.

I have searched the forum but can find no mention of problems with the oil pump.

[Ian]

I seem to recall that Frank Westworth had this problem. It was found to be a seal either between the rear chaincase or the primary case, I can't recall. It allowed oil into the gearbox.

It's a big job to do, and the seal is pennies! I'm pretty sure Mr Negus of this parish has written about this.

Hope this helps,

Ian.

[Anthony Duffield]

Ian,

Many thanks for the reply, I had another good look yesterday with the inspection cover off and engine running, moving the oil control lever to max by hand I could not see any oil leakage around the oil feed pipes, I did this until the engine began to really smoke so feel confident that the issue is not the pipes or connections.

There is an O Ring between the pump and plate it bolts to if the shaft seal is leaking it could get past the O Ring causing the gearbox oil level to rise, I need to measure how much oil is leaking into the gearbox and for how long. The pump is a Yamaha part ANL have one in stock so that will be the next step.

Some years ago I had gearbox oil leaking into the enclosed chain space, that was as a result of a worn lip seal that runs on the sprocket, not an easy job for sure.

Thanks again for your help, I will let you know what I find.

Tony

[R Williams]

Hello, on my air cooled bike, I fitted a perspex cover on the gearbox instead of the aluminium one which makes for easy checking of the level . I glanced at it one day and the level was over halfway up the perspex and it turned out that the supply pipe to the pump was split !!.

[Interpol2471]

Nice quiet gearbox lol