Yamaha 100 hp 2000s flywheel locked up

[tavacska]

I am going to buy this motor, 4 stroke. The owner says the flywheel locked up in a fishing trip because of the lower unit. The lower unit can not be taken off because the shaft locked into the powerhead.
It said to be caused by the bushing, or the oil pump problem by a mechanic. How bad the motor could be?

 

[saltchuckmatt]

I am going to buy this motor, 4 stroke. The owner says the flywheel locked up in a fishing trip because of the lower unit. The lower unit can not be taken off because the shaft locked into the powerhead.
It said to be caused by the bushing, or the oil pump problem by a mechanic. How bad the motor could be?

Overall what he is saying doesn't make sense. Here is what happens. If the gearcase is not removed periodically and greased, the driveshaft gets stuck in the bottom of the powerhead (crankshaft). Usually means the motor becomes a parts motor. Flywheel or oil pump has nothing to do with it.

 

[99yam40]

getting to and cutting the drive shaft off maybe needed, Not sure how or where to do that.
then drill and tap a hole in the shaft to try to remove the cut off piece out of the power head.
this all depends on what is sticking the drive shaft

 

[tavacska]

Thanks. That's pretty much what I assumed.
I am not familiar with Yam. Can't I pull the powerhead and replace the crankshaft?

But with a double thinking, the motor got seized and that means either the power head or lower unit got blown, or both in this weld case.

I also learned that the oil pump gear spindle may weld itself and LU shaft.

Just wondering if $1000 is worthy for a future rebuild project.

 

[saltchuckmatt]

Thanks. That's pretty much what I assumed.
I am not familiar with Yam. Can't I pull the powerhead and replace the crankshaft?

But with a double thinking, the motor got seized and that means either the power head or lower unit got blown, or both in this weld case.

I also learned that the oil pump gear spindle may weld itself and LU shaft.

Just wondering if $1000 is worthy for a future rebuild project.

Not from where I'm from.

 

[tavacska]

I bought the engine. Going to see what happens to the shaft.

The drive shaft stuck to something, but not the crankshaft, which is good. I found this out because when I tried to drop the lower unit, it dropped 1 inch and stuck somewhere.

I need to remove the powerhead. Does anyone has PDF manual for 2001 F100? How many bolts to remove to take out the powerhead?