Worst day ever... please helid

So I finally got the wife agree to go out on the pontoon today with the kids. We hit Eagle Mountain and did a little fishing... not a bite. So.. we decided to leave early and the motor overheated on the way back to the launch. It is a Yamaha 50hp... not sure of the year, boat is an 82... I think motor is newer though. Anyway, the motor was shooting the water out just fine... so I was confused... I thought that the way a boat motor cooled itself was buy circulating water through the motor and shooting it out the back.. and as long as you saw that steady stream, you should be good. So we waited a bit, let it cool.. moved back towards the launch and it overheated again.. I was sure to check it multiple times while moving and the motor was shooting water out just fine. Oil was full, just filled it last night... Anyone got any guesses as to what it could be?

I can't afford a mechanic right now... not to mention wife will NEVER go back out with me.. not sure if I am putting that on the pro or con list yet though..

Anyway, if anyone can help me with some advice, I would be grateful.. Thank you.

Even if the tell tell stream is good I would start with a impeller replacement
Takes about an hour and easy to do yourself for around 50-75 bucks

You tube the motor and process

Clean the poppet and thermostats with Lime Away.

This!

Yep , should be a easy fix. I would still replace the impeller to make sure you're getting the most out Of it

buying used like that you also never know what previous owner did, dry start motor no muffs etc, Ive even seen them slam it in gear and run it on muffs and needless to say walked off. So all advice you have received is correct.

If the thermostats are hung open due to debris or corrosion, the engine will still have the telltale, but water will run through too quick to cool the engine properly. That is the most common scenario. Its also possible that water passages in the block are partially blocked.

Pull your thermostat(s)first and clean/replace as needed.

Too much water flow will not cause a motor to over heat. If anything it will prevent it from reaching the proper operating temp causing it to run rich.

T-stat, pull it, put it in boiling water see if it opens. If not replace.

^^^^^^this i bet you find it bad.
I learned a lesson from Marc Mitchel at lake fork on the thermostats.

Thanks for all the help on this.. I have located the thermostat, but I cannot locate the pop-it valve... i is not listed on the parts diagram..

http://www.crowleymarine.com/yp/VC457073/cylinder-crankcase-50tlra-2002-50hp

Anyone have any thoughts... I can post pictures of both sides o the engine if it will help

It is there with the thermostat on early models. 34, 35,36: http://www.boats.net/parts/search/Yamaha/Outboard/1984/115ETXN/CRANKCASE%20CYLINDER/parts.html