1990 3.0 mercruiser having overheating problems and lost of power

[silly132]

i have a 1990 sea ray with a 3.0 alpha one motor. I bought it last year and it ran fine all summer long. I winterized it and took it out back in June and it ran fine until 2 weeks ago it wouldn't plane at its usual way but since it was the end of the day i didn't think much about it. So i took it out yesterday and within 10 minutes after i left launch it i looked behind it and the water was churning brown. I turned it off didn't notice anything wrong then i turned it back on and it was overheating. I turned it off and a fellow boater towed me back to the launch. Once i got boat home i fired it up on the muffs for a few minutes and i could smell something burning. So i decided to check to see if the water pump was working and removed all three hoses and no water was coming out so i know the impeller is bad so I'm going to replace it. But my main concern is why did the brown discharge come out and i notice I'm missing a bolt. Is this why? and if so what is this hole where the bolt is missing. Notice on the other side the exact same hole but with a screw in it with rubber cap

 

[oldjeep]

That is your gimbal bearing grease zerk. Pretty sure the hole on the other side is always open.

 

[nateo]

I feel compelled to share some things I learned from others on this forum. Steps to troubleshoot overheat problem. With boat on trailer...Shift remote control into forward gear. With engine off try spinning prop counterclockwise. If it locks then your engine coupler is good (this step takes like 3 minutes but could save you hours). Determine if water flow problem is inside or outside boat. One can do this by removing just the one water inlet hose that comes into boat at transom. Remove either before it reaches power steering cooler or attach another hose to transom so water doesn't go everywhere. If no water comes into boat, then proceed to remove outdrive check impeller, etc. Removing the drive without a stand and experience is doable but a bit of a pain.

 

[silly132]

Ok thanks^^ and if no water pumping out all three hoses does that mean impeller shot? And installing a new impeller should fix the overheating?

 

[Rick Stephens]

Check the entire cooling system. You can melt exhaust shutters if you got it really hot. The water pocket will melt as well - its the plastic fitting the water pipe from the pump plugs into. If the impeller fractured pieces can stick in other parts of the cooling system. Again, if gotten hot enough, the water pump base can be deformed or melted. Once you get it hot you need to look at anything else that might have also been cooked.

Rick

 

[airshot]

If you had any type of overheat I would want to remove and replace the impellor for piece of mind, also look at exhaust shutters as these normally burn away in an overheat case. May want to do a complete flush and clean of the cooling system and check all the hoses for any blockages. These are things you should do on a new to you boat anyway just to be sure she is seaworthy.

 

[nateo]

Ok thanks^^ and if no water pumping out all three hoses does that mean impeller shot? And installing a new impeller should fix the overheating?

What 3 hoses? If you have a power steering cooler there's a small possibility it could be clogged. If you end up removing outdrive, be sure you try sticking garden hose into water inlet hole in bell housing and run engine that way. This will also tell you if problem in inside boat or out. Do this before splitting the outdrive apart to replace impeller. I replaced my impeller tonight by leaving upper on but splitting them in two. there are multiple ways to approach these tasks. Needless to say replacing my impeller did not fix it. I'm keeping the old one as a spare though. Never through away old parts that you've replaced that are still good.

 

[Rick Stephens]

I would disagree. The outdrive needs to be pulled, the entire pump, water pocket, and cooling system inspected. The exhaust shutter should be looked at and if not in one piece, fished out before other damage is caused. If the impeller has fragmented it also needs to be tracked down. Not a place for shortcuts.