Starting an old 2 stroke 15hp Yamaha outboard?

Hi,

I just bought a boat that has an old 2 stroke 15hp outboard. It is my first outboard.
I have no user manual so notsure of the date or model)
It has started well but today (which was cold and wet) it wouldn't.
I've pumped the primer till hard (and I can see fuel filling the little reserviour under the cover. Cleaned the spark plugs.
The only thing I have noticed is that when I looked today there was rod that had seemed to pop out of the back of the engine. Put it back in (and looking under the cover it seems to move some sort of level about a quarter turn).
I have remote levers but no cutout switch. Pull start only.

thanks
Chris
Any suggestions or is it off the the mechanic?

Chris