I bought a new 3.5 L Head from Grainger to replace an older B&S 3.5 used to power a water pump. Mounted the engine, mounted the pump, added 18 oz of B&S 30 weight oil, added gas and fired it up. It ran great for about 5 minutes and then locked up tighter than drum. Did I forget something before the fire up? I read the book and can't find anything I missed. Any ideas???

Thanks,
Mikey

You might want to disconnect the pump and make sure it's the engine thats locked and not the pump causing the issue. If it's the engine, then you need to contact Grainger and see what their policy is in regard to your issue. If you serviced the engine as you described then it should either be repaired or replaced under warranty.

As in it seized? I'd check the oil again...

The motor is fine, it runs like a top! :woohoo: The pump impellar (direct mount pump) had froze up against it's back plate. I had to saw the back plate mounting screws to release the impellar in order to remove the impellar from the shaft. Anyway, thanks for all your help! :)

The motor is fine, it runs like a top! :woohoo: The pump impellar (direct mount pump) had froze up against it's back plate. I had to saw the back plate mounting screws to release the impellar in order to remove the impellar from the shaft. Anyway, thanks for all your help! :)

Let me ask this...because somebody else surely will...

did you have water in the pump before you started the engine?