Did my boat seize a motor, or could it be in the lower unit

Hi,I am new to this forum. I was out in my pontoon boat this weekend 7/26/14, and going back to the dock to load the boat up on the trailer, it just shut off. I was going no more than 5 mph. I had to get towed into the dock, because the motor would not turn over. At that time, I didn't know if it was the starter... I took the starter out yesterday and it works fine. So something is froze up somewhere. It is a 1999 2-cycle Evinrude 115. It has plenty of 2-cycle oil in the reservoir. It did not even hick up or struggle, when it shut off. I am hoping that the motor did not seize. Can it be in the lower unit gearing, that is keeping it from rotating? Does anyone have any suggestions, on how I should troubleshoot this thing, before I just start ripping through things. I am thinking of taking the heads off, to see if the cylinders are scored, and would not mind starting with the lower unit, if it can be a possible cause. Any help or suggestions would be very welcome. Thanks, Gator from Helendale California!!!

Assuming the engine did not overheat and "temporarily" seize the engine..... dropping the lower unit will tell the tale of whether the problem is the powerhead or the lower unit.

Does the starter even try to spin or does it just sit there like it has no power?
Bill

Wow! On Sunday when I worked on it (after it failed on Saturday), I tried putting the controls in forward and prying the prop, to see if I could get it loosen up, to no avail. When driving home in California traffic yesterday, which takes me two hours to get home, I thought I might put it in reverse and do the same thing with the prop (since it failed when in forward). When I got home, I did this, and with a little umph, it spun. I put the key in and it started right away, with no apparent malfunctions. I even put it in forward while it was running and it worked with no problems, or noises. Now I am more than curious. Doe anyone think that it could have some debris in the lower unit that got caught up in the gears. It was barely idling, when it stalled out on the water. I am going to drain the gear oil this weekend, to see if I can see anything... Thanks for the replies!

Thanks for the reply kimcrwbr1. I changed the impeller two years ago, along with changing some of the seals, as it was leaking gear oil out of the prop shaft carrier. The prop was easily spun when in neutral, when this thing was locked up. If it was debris, I have to wonder were it came from... I am going to drain the oil, and depending on what I see, just go ahead and pull the lower unit off and take apart...

Check to see if your overheat warning horn is functioning................

Key ON (engine NOT running). Ground the TAN wire that's attached to the warning horn OR the heat sensor lead where it exits the cylinder head. The horn should sound steady and constant.

If it does not, find out why as should the engine overheat, that's the only warning you'll receive before the powerhead screeches to a sudden halt.

Take off your prop and check for fishing line or similar behind it.