Newbie outboard question: what drives the prop?

[yourmomm]

Hi. Sorry about the basic nature of this question but I'm just teaching myself how to service outboards fr the first time.

So I've inherited a 2hp yamaha (2cmh) which doesn't work. After some effort, I've got the engine running cleanly, and the gear splines look fine, but the prop doesn't turn, which I'm assuming means someone has hit a rock at some point and stripped something. But since I don't know how the prop is turned, I can't see what's stripped (as its presumably not there anymore).

I doenloaded the attached exploded parts diagram, and it's still not clear to me what turns the prop from the lower gear. Is it the pin (40 in the diagram)? If so, mine is flush with the gear shaft, so I need to source a new one. If not this, what is it?!

 

[VicS]

Yes the pin # 40 should drive the prop.

Commonly known as a shear pin. It will shear if the propeller strikes an obstruction Yours has sheared.

Many people improvise with piece of rod a of something they think/ hope will shear when necessary. It should be possible to determine how long it must be by looking at the back of the prop hub.