Seeking help with 70 hp Mercury 2 stroke

[slmcnulty]

My husband acquired '76 Lund VFR-15. The boat ran good a few years ago. The motor was worked on and winterized 2 years ago. We got the boat home, cleaned up and on the water today. The battery is brand new. The motor starts up and runs right away. We putt around the lake a few moments going slowly to start. There seems to be a slight bog in the engine. After another moment my husband continues to go through gears. We get to full throttle and the engine stops running and starts smoking. Won't restart. Doesn't seem to be getting spark. There is one click in motor when key gets turned. We paddle to shore.
I am seeking suggestions on possible causes and advice on where to start the repairs. It is an outboard Mercury 700 70hp 2 stroke 3 cylinder Thunderbolt ignition.
Thank You.

 

[racerone]

Is it overheating ?-----Waterpump impeller inspected / replaced ?------Mixing gas and oil at 50:1 on this motor ?

 

[slmcnulty]

It did overheat. Not sure why. I will be checking the impeller today. The oil is mixed to spec. I will update with further information as it develops.

 

[clueless75]

Sounds like it seized... If it overheated the powerhead or the water pump has seized, resulting in a "click" when you turn the key as the starter wouldn't be able to crank the engine at all. Remove the lower unit, check the water pump (it is most likely melted), and try cranking the motor by hand after removing the lower unit. If it turns, then the water pump seized; if it doesn't turn, then the powerhead seized. If the powerhead seized, then there isn't much you can do depending on what has seized. If it's the water pump, then simply remove the old pump, buy a new one, and install it. Hopefully it's just the water pump!