Mcculloch Power Mac 310 oil pump inop

[kenmpls]

I have a McCulloch Power Mac 310, model 600042D, serial #14-014429 with an inoperative oil pump. The pump does not pump oil either with the manual button or automatically when running. The pump does not suck oil out of the oil tank. All of the hoses, oil passages, and the screen in the oil tank are clear. I removed the pump and covered the 'piston port" from the engine and the manual pump button still does not suck oil from the reservoir. I'm thinking that there must be a check valve somewhere in the pump or screen that is sticking open. Anyone know if or where a check valve is located? Is replacing the pump the only option? Thanks for any comments.

[donbj]

Odd that neither will work. On some old homelites the same vintage as yours I'm working on. The brass fitting that the lines connect to right at the tank is a check valve. The orings in your pump plunger might be bad too.