V11 CAFE SPORT OIL PRESSURE PROBLEM

[voncrump]

I just had a call from a friend about a problem with a rebuilt motor on a cafe sport.
The oil pump does not want to prime. What could be going wrong here?
Cheers, voncrump.

[Kiwi_Roy]

Leaky filter "O" ring perhaps.
A common fault is the old ring sticking up so you end up with two.

[Chuck in Indiana]

Has he tried filling the oil pump with assembly lube?

[dxhall]

I had a similar problem when I rebuilt my Sport 1100 motor.  I disconnected one of the oil lines to a cylinder head and filled the line with oil.  It took a while, but eventually no more oil would go into the line.  At that point, I reconnected the line and then spun the motor over with the spark plugs out and a valve cover off and watched to see if oil came out from the rocker shaft.  It did.  I concluded that the pump must be primed.

[voncrump]

Thanks for the responses so far.
We have tried pumping oil down the rocker cover feed to the point where the pressure was enough to switch the oil pressure switch, but the pump will still not pick up the oil. I feel that the pump may be sucking air somewhere. The pump was lubed before assembly. Even if there is a leak on the pressure side the pump should still shift some oil but it does not seem to be doing anything at all.
Next step may be to start dismantling things to check in the sump and the oil pump itself.
Keep the ideas coming.
Cheers, voncrump

[Chuck in Indiana]

Thanks for the responses so far.
We have tried pumping oil down the rocker cover feed to the point where the pressure was enough to switch the oil pressure switch, but the pump will still not pick up the oil. I feel that the pump may be sucking air somewhere. The pump was lubed before assembly. Even if there is a leak on the pressure side the pump should still shift some oil but it does not seem to be doing anything at all.
Next step may be to start dismantling things to check in the sump and the oil pump itself.
Keep the ideas coming.
Cheers, voncrump

Looks to me that you have no other choice.

[Howard R]

One of the more popular things to get wrong is the "tabs" on the oil pan gasket, if one of those got shifted around it could either block, or allow an air leak on, the pickup side of the pump.  That's where I would start looking, taking the oil pan off is probably easier than going into the timing chest to look at the pump so start with the easier stuff.

Good luck!

Howard

[voncrump]

Just an update. Sump was taken off and a hose connected to the oil pickup and a funnel raised in an intravenous drip fashion. The motor was cranked over and almost immediatly sucked the oil through.
Another fine job from an enthusiasts back shed. The bike is running fine and sounds awesome.
Cheers, voncrump