searay heating issues

[richc007]

Hello all....

Got a 1988 searay 4.3 mercruiser that heats up. Ran great last year, now first time out we hit 200 deg. Before i got it shut down. Tore the t-stat out and all looks good, but after getting towed this great guy gave me a few things to look for. I took the little water intake grates off on each side of the lower unit and it had rubber chunks that came out. Bingo..... So now my question is where did they come fron and where to next?

He said there is a raw water pump I believe that was probebly the isssue... Question is. Is it the round cylinder that the hose from the transom goes into, and the other end connects to the water pump. There is also 2 more smaller hoses that go to somewhere else. I ddint get that far. or is it the water pump itself?

Thanks in advance for all your help guys.

 

[ShaneCarroll]

Re: searay heating issues

Those little rubber chunks you speak of would be your impeller. When is the last time the impeller was changed on your engine? It's an easy DIY-er, pick up an impeller kit, probably in the neighborhood of $25-$45. What type of outdrive do you have? I am guessing Alpha One Gen I? You will also have to flush and replace your lower unit oil in this process, most of them take less than two quarts.

 

[richc007]

Re: searay heating issues

it is an alpha1 lower unit. Is this a pretty hard project to do. Do i have to take the lower unit apart? I already have the oil and had planned on changing it anways, so thats a good deal...

 

[180shabah]

Re: searay heating issues

Thermostat only controls minmum temperature.

Raw water pump is a good place to start, it is inside the lower unit of your outdrive. The first thing you need to ask yourself though, are you comfortable with this type of repair?

 

[180shabah]

Re: searay heating issues

Is this a pretty hard project to do

Start by cruising through the adults only section, download the manual for your drive.

 

[richc007]

Re: searay heating issues

is it a pretty complicated repair. I am prety mechanically inclined, but know nothing about boat repairs. does the lower unit need to be completly disasembled?

 

[MikDee]

Re: searay heating issues

No, it's not that hard, requires a bit of muscle the average guy can handle. If it's a Mercruiser the bottom part of the outdrive has to come off, with the driveshaft, & water pump housing mounted on it. Most of us guys here have done it ourselves, no problem. Just read up on it as mentioned.

 

[ShaneCarroll]

Re: searay heating issues

It's basically a matter of removing 4 (or 5, depending if there's one under the "trim tab") bolts, pulling the lower unit off, removing the old, and in with the new. DO NOT forget any of the o-rings, gaskets, or seals. The 5th bolt, which I am not sure if it is on a Gen I drive, you have to take the trim tab (fin right above the prop) off by using a 1/2"(?) extended socket from the top, in that little hole. After that, go underneath where the trim tab was sitting, and there is a 5th bolt there.

 

[richc007]

Re: searay heating issues

I want to thank each and everyone who replied to this. Seems pretty basic, but I can say that reading this you guys gave me a bit more confidence. Thank you very much. Will tackle it tomorrow if the parts are in stock locally..

 

[richc007]

Re: searay heating issues

One final thing. Does the unit need to be in gear before starting the procedure?

 

[MikDee]

Re: searay heating issues

Yes, in forward,,, don't forget the stud in the front, by the shift arm, and the hex head hidden bolt holding the zinc trim tab on from the top, then the bolt under the trim tab,,, the other bolts on the sides are visible. Take note there is a small O-ring and oil passage between the upper, & lower, units located on the left side when you split the drive. When replacing the impeller, make sure you put it on the driveshaft key properly, use dishwashing liquid liberally on it, and when putting the housing back on, spin the driveshaft by hand clockwise as you seat the housing in place.

 

[richc007]

Re: searay heating issues

I may be in trouble. Got too excited and took the lower unit off without putting it in forward first. What next... Am I in trouble.. It sure came apart easy enough, and sure enough the propeller is in chunks..

 

[MikDee]

Re: searay heating issues

Actually when you remove just the lower unit, there is a small spline piece on the front of the lower unit (the shift shaft) that controls the shifting, and a small coupling that the spline slips into on the upper unit. Make sure it's lined up properly for shifting. I don't remember if it can only fit together one way, or not? But if not, I have a method to line it up, just let me know, good luck, Mike

 

[180shabah]

Re: searay heating issues

Got too excited and took the lower unit off without putting it in forward first. What next... Am I in trouble..

Seriously - get the manual.

and sure enough the propeller is in chunks..

Find all of the pieces, or they will end up clogging passages.