New Oil Pump

just bolted in a new oil pump.

when i tighten it down to the case the cover clamps down to tight and the shaft of the pump is very hard to turn. the cover is to tight on the gears inside the pump.

I slide the chain gear on the shaft and still cannot rotate the shaft with my bare hands.

once i loosen the bolts up it spins freely.

im afraid to install it like this and the first time i start it the shaft shearing off. im sure it would only take a few seconds after starting before the steel gear wore into the aluminum cover (if the shaft did not shear instead) but that just don't even sound like a good idea.

anyone ever had this issue?? or any suggestions. Did i just get a faulty pump??

thanks
Kyle

who's the pump made by , is it a yamaha

did your other pump feel there same when you tried it when you tore it down?

I will add that when I rebuilt mine the new oil pump was easy to turn after it was bolted in I don't think being hard to turn is wright just my thought, what tork are u putting on bolts

think i found the problem over the weekend.
yes it is a yamaha pump.

seems to be the shaft on the new pump is slightly to big and when i torque the pump down in place the shaft will not turn inside of the hole in the case.

i put shaft from my old pump onto new pump and bolted in place and all worked free as it should.