YZ426F oil pump damage

[michaeltaz]

My brother just bought a used 426. I checked the oil pump. Looks like metal pieces went through rotors, according to marks on rotors and sides. How critical are these marks? Must I replace the rotors or cover plate/housing aswell? Can I test the pressure of the oil pump somehow? The oil side water pump seal had blisters on the side where the numbers are. Could this be from overheating? Valve clearances I shimmed. Clutch basket I filed notches out. What else must I check? How can I check timing chain and piston without tearing apart?

 

[Pete Payne]

As a rule of thumb I normaly replace the whole thing.

 

[michaeltaz]

Pics of oil pump

I removed alot of sand and aluminium paste from the oil tank. Is this oil pump still ok? I know how critical the oil pressure is, on the modern high performance 4strokes. On an old type of 4stroke I would re-install the the pump.

 

[Ol'89r]

As a rule of thumb I normaly replace the whole thing.

For the price of the pump and the potential for engine damage, I would take Petes advice.

I wouldn't use that pump in an old XR much less a modern YZF.

 

[IndyMX]

Why risk thousands in damage for the price of an oil pump..