Lower unit sheared bolt

[Snarrows]

I was intending to replace the water pump impeller in the lower unit of my Yamaha 175. I loosened seven of the eight bolts, however, the eighth bolt in the cavity behind the zinc anode that is inserted from the cavity upwards sheared (not the anode bolt that is accessed from the top) in such a way that it is nearly impossible to try to remove it using an extractor. My question is: The bolt that is inserted upwards threads into the upper unit . Is it possible to separate the lower unit without removing the remaining portion of the bolt since the head is no longer on the bolt? Thanks.

[99yam40]

yes it should if you have all of the other bolts out.
but the corrosion around the remains of the bolt may make it difficult

[Snarrows]

Thanks for your response

[TownsendsFJR1300]

You may actually have a broken stud left to work with (remove) once disassembled...

If you access to a MIG welder, PLUG WELD a nut to the broken stud and then spray some penetrating oil
on the stud and work on spinning it out. The heat immediately after welding the nut will also help break it loose..

I'd disconnect the ECU just to be safe..

[Snarrows]

Tnx, Scott. Good advice & much appreciated.