40hp overheated and other issues

The motor is a 1990-96 ish, (cant get a full SN# off the tag XX267832) 40hp oil injected 4clyinder 2 cycle outboard.

We were out for the first time the other day in a pontoon that I just bought. we were idling near shore when an alarm started sounding. Now bear with me because I am new to anything larger than 10hp, and never heard an alarm on a boat before. I thought that it was something stupid like a low voltage alarm or something like that because it was coming from the dash and the wiring on this thing is a joke. (I later realize that this was not the case) :facepalm:

To make a long story short, as we pulled away I notices smoke coming out of the engine. I realized that no water was cycling through, so I shut it down. It was probably like that for about 4-5 min. I let it cool, raised it to check for blockage and started back up once the alarm stopped.
It was running fine for a few minutes until it seemed to miss a couple times and then it would only hit about 3000 rpm, about half power. So I shut it down again, and this time I had a hard time re-starting it. I limped it back to the dock and loaded up.

I have read that some motors have a "SLOW" run feature in the event of overheating, but how do you reset this if that is the case.

I inspected the spark plugs and they don't look burnt, and externally everything looks fine. There is a bit of 2cycle oil on the carbs, and I wonder if that is what is causing the starting issue. But I have no idea how it got there.

Any help or advise is greatly appreciated.

Thanks

Re: 40hp overheated and other issues

If you have no water coming out of the pee hole, it is either clogged, or more likely the impeller is shot. The fact that the alarm came on and you had no water coming out leads me to believe that the impeller is bad. You will have to remove the lower unit and replace it. I hope that you haven't done any damage by running it that way, you better service it before taking it out again or it will melt down on you!

Re: 40hp overheated and other issues

I will look into replacing the impeller. Thanks for the tip.

I hope I didn't do any damage either. As we started back out I made sure that water was cycling through and out the pee hole. It was... However at that point it wouldn't rev up past 3,000 rpm. And once I turned it off, I had a hard time getting it going again.

When we first started out, it was a bit stubborn to start and stay started at low RPM/idle, and it didn't seem to me that the motor was reaching its full potential. Just sounded like it had a lot more to give, but the throttle lever was maxed out, leaving me to believe that there may be something wrong with the cable adjustment, fuel lines or the fuel mixture. It?s an oil injected motor, so I just assumed that the mixture was ok. But when I noticed the carbs covered in raw 2 cycle oil anything is suspect at this point. Any ideas?

Thanks again, and any advice is greatly appreciated. I'm new to this, and I want to learn as much as I can.

Re: 40hp overheated and other issues

I have never worked on an injector motor but I have heard if issues where people premixed their fuel instead of letting them inject. Maybe somethijng has gone haywire with the injection system, and again, purely a guess.

If your motor was that hot, you may have been vapor locking making it hard to start. That is when the fuel is overheated in the carb due to transfered heat from the block.

Something is definately wrong if you see oil covering the carbs, probably a leak of some sort. The gasoline will evaporate leaving the oil and mess behind, or maybe something is leaking from your injection system. Maybe your oil is excaping rather than mixing?

Re: 40hp overheated and other issues

Look on the powerhead and see if you can find a s/n disc like this one:

http://img84.imageshack.us/img84/8224/391496208.jpg

Gerry

Re: 40hp overheated and other issues

Ok, so I had a guy check it out today. Turns out the power pack was bad leaving me with only two cylinders. The impeller apparently was worn enough that it could not keep up with the reduced rpm level. Plus the carborators need to be rebuilt. I figured the carborators needed attention, but I am glad that there was nothing major. He checked compression, and said that everything looked good.
Although I'm not happy about having to sink more money into a doat that I just bought, I am glad that it can be fixed for the weekend.
Thanks for the advice.

Re: 40hp overheated and other issues

Hope your guy guarantees his work. Two cylinders dropping can be a sign of switchbox, trigger or stator problems. Without a s/n we have no idea of what system your motor uses. Also since you bought a pontoon, make sure it is propped right. The biggest killers of two strokes are pontoons with overpropped motors. I think you may be in more than you bargained for