Since I sank my skiff 3 weeks ago, I needed to buy a replacement engine... I had a 77 rude 25 hp tiller so I got another Evinrude. My stupid question is this, " what is the little knob that sticks out the end of the tiller handle, beyond the twist grip?" Also, the engine now has a push button start switch where I would imagine it had a key switch. Did they come with a key switch? Lastly, the engine wont start unless I choke it for 1 second, even when warmed up. Any suggestions?