View Full Version : 43 Overheating Water can go out not in

05-04-2006, 12:54 PM
"So last year I had a small overheating problem, if I was stopped or went slow too long, it would heat up to 220-230, and when I accelerated, it would go back to 160.

This year, first time in, it overheated after 10 minutes warmup at the dock ! So I went out figureing it would cool down. Then blue smoke started coming out ! So I shut down and got towed and went home. Then after it was cooled off, and I added 2 quarts oil, I fired it up, and it might be OK. The I went to work to try and figure out the problem. First water pump, removed, seems fine. Then thermostat housing, looks OK, was going to replace anyway, but I wanted to check water flow.

Here is where it gets interesting. If I disconnect the hose going to the stern drive, and put my house water hose in it, and turn on the water, it comes out the water inlet by the prop pretty good. If I put the adapter on the engine for normal out of the water running (where the water was just coming out), and turn on the hose, nothing comes out the other end where I just had the hose ! Then I remove the little plates on the water intake, and a bunch of hard rubber pieces fall out. So I remove them and think I solved the water flow (even though now I need to figure out where that rubber came from) and still same water flow problem.

HELP ! BTW, this is my first year of boating, last summer I bought it, used it for 8 weeks, winterized it myself (may have done it wrong) and now this ! Any advice is appreciated.


05-04-2006, 02:22 PM
"If you removed the lower gear case and looked at the water pump, did you replace the impeller? Do the rubber pieces look like they were once part of an impeller? Good chance the motor wasn't maintained well before you bought it. Your water pump should have no problem drawing water up from a body of water or with the muff if the impeller is good and there's no blockage. If you ran it dry (no water getting in), you need to replace the impeller and if you have the Gen I Alpha One drive, you have the plastic water pump housing, which is also melted and needs to be replaced. DO NOT just replace the impeller if it overheats as badly as it did the last time. If you do, the pump body is warped and won't keep water out of the gear oil, which will keep the gear oil from doing its job."

05-04-2006, 02:27 PM
"I didn't take the lower gear case apart, just the water pump on the engine (I am new to boats). That makes sense now, thanks. Do you think I toasted the engine since it runs now without smoke ? (not under load, just running a little over idle)"

05-04-2006, 03:00 PM
"The pump you checked has nothing to do with water getting into the motor. The raw water pump is in the lower gear case and needs annual maintenance. The motor may be OK but overheating it isn't one of the best things you can do to it. Change your motor oil, it's useless now. Re-read my last post about raw water pump maintenance. If you're good mechanically, get a manual for your motor and drive. You don't really need any special tools to replace the water pump and impeller but you do need to know how it comes apart and goes back together. If you ever want to do any work on the upper or lower gear cases, you'll need specialty tools.

There are things that need to be done for a boat that are absolute- water needs to get in for cooling, oil and filter needs to be clean and changed about every 50 hours of use (if you don't have an hour meter on the boat, get one) and any seals that go near the water need to be replaced occasionally. I don't know where you are but winterization is a big problem for some people, too. They see it as an unnecessary expense until they freeze their motor and need to replace it. When a boat is winterized properly, the oil/filter gets changed, gear oil is changed and the impeller's function is either checked or it's replaced. Also, the water is drained from the block or replaced by RV anti-freeze and the motor is fogged before being shut off. This is only a partial list.

Again, I don't know your boating history or where you are but these things need to be done in order for you to be able to enjoy your boat. Boats crave attention more than cars."