1973 115 hp outboard waterpump

Chngingtymes

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Jul 4, 2003
Messages
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Hey,<br />I have been noticing the water flow coming from my 1973 115 hp mercury outboard has been getting less and less. I am sure it is the water pump for it completely stopped today.<br />Couple of questions, where can I get one? And is the following posted by someone in August in 2002, the same procedure fro 115 hp.<br />Thanks for your help, anyone.<br />chngingtymes@kc.rr.com<br /><br />Previous Post:<br />3******. Mine has no thermostat, but not sure about yours. I would bet the water pump impeller in your outboard is toast. Time to replace it. You can find a good Merc service manual on Ebay for not a lot of $$$...they are superior to aftermarket manuals like Seloc or Clymers.<br />To change the impeller, you will have to drop the lower unit off the outboard. Here's how:<br />1.) Put the outboad in neutral at the control box (throttle& shift lever by drivers seat) Raise the outboard up, in traveling/trailering position.<br />2.) Remove the prop<br />3.) Remove the trim tab (the shark fin above the prop)<br />4.) Remove the nut from the bolt that is in the trim tab cavity.<br />5.) Remove the nut from the bolt that is behind the trim tab cavity.<br />6.) Have someone hold onto the cavitation plate while you remove the two nuts that you can see on either side and above the cavitation plate.<br />7.) Now everything from the cavitation plate on down will slide down/off as one unit. <br />8.) Look at the base of the long driveshaft, there is a housing surrounding the driveshaft that should be held on with 2 or 3 nuts. Remove these nuts, pull the housing up off the driveshaft and check the impeller. The impeller looks like a rubber pinwheel with several rubber blades.<br />9.) The impeller also fits on the driveshaft. Pull the old one up and off and put a new one on. Put the housing you took off back on. Gently push the housing down against the impeller as someone turns the driveshaft clockwise. You want the impeller vanes to bend counterclockwise so the impeller fits back into the housing you are re-installing. <br />10.) Bolt the housing back down and put the lower unit back on the outboard leg (Reverse the order of removal)<br />11.) It may take more than one try to get the Lower unit back up correctly...just takes patience.<br />12.) You'll know its back on correctly if the prop spins freely in either direction when in neutral, ratchets clockwise when in forward, and turns only counterclockwise under some force when its in reverse.<br /><br />Sounds intimidating, but its not. Impellers should be replaced every other year if you run only in fresh water, and every year if you run in salt water. Have fun or pay to have it done!<br />Thanks<br />D.
 

The Marine Doctor

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Jul 25, 2003
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2,177
Re: 1973 115 hp outboard waterpump

The new impeller you require is 89984T available at any Mercury or Mercruiser dealership.<br /><br />Just follow those directions...there should not be a problem.<br /><br />TMD
 

The Marine Doctor

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Jul 25, 2003
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2,177
Re: 1973 115 hp outboard waterpump

If you have trouble finding one...just email me @<br /><br />marinedoctor@shaw.ca<br /><br />I will send one out...we stock them<br /><br />TMD
 

Chngingtymes

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Jul 4, 2003
Messages
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Re: 1973 115 hp outboard waterpump

Thank You Ron,<br />How much do they cost? How soon could I get one.<br />Thanks again<br />D. Medlock
 

The Marine Doctor

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Re: 1973 115 hp outboard waterpump

Email me your contact info...should be able to have something sent to you on Monday.<br /><br />TMD
 

Chngingtymes

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Jul 4, 2003
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Re: 1973 115 hp outboard waterpump

Ron,<br />I took the motor apart as directions showed, and looked at the impeller, and to me, it looks new. I just bought the boat.<br />The only thing is, is looked like the fins on one side were pushed too tight against the one side, while the other side was almost straight.<br />Does that mean it is bad?<br />I put it back in, and it was oversized(normal I guess), and bent the fins back into position. It is sitting straight now, but not sure how it could have gotten wedged or off center like that.<br />Maybe I just need a new one, but this one is black rubber, stiff, but bendable, and as I said, looks new.<br />Thanks for your help.<br />D. Medlock
 

profish00

Petty Officer 3rd Class
Joined
Jul 18, 2003
Messages
91
Re: 1973 115 hp outboard waterpump

The impeller does hug 1 side of the waterpump housing. I just replaced mine on a 1993 150 blackmax didnt need replaced just the teltale wasnt strong and still not very strongafter I replace it. THEY JUST RUN HOT ITS A MERC...<br /><br />hec what do I kno,drive it like you stole it
 

The Marine Doctor

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Jul 25, 2003
Messages
2,177
Re: 1973 115 hp outboard waterpump

Both sides of the fins should look the same...if one side is flat...its worn. Should be replaced. When reinstalling it...turn the D/S clockwise as you press the housing over the impeller, so the fins bend the correct way.<br /><br />TMD<br /><br />BTW...Ron is my Boss :) <br /><br />My name is Jay<---his son<br /><br />TMD
 

Chngingtymes

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Jul 4, 2003
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Re: 1973 115 hp outboard waterpump

Thanks everyone for your help.<br />Nice to meet you Jay.<br />Gotta hand it to you. Working for Dad can be tough. ;) <br />I am going to try to find one today and if not, I will order one form you and Dad.<br />How long does it take to get here. I am in Kansas City Missouri?<br />Thanks again<br />D. Medlock<br />chngingtymes@kc.rr.com
 

The Marine Doctor

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Joined
Jul 25, 2003
Messages
2,177
Re: 1973 115 hp outboard waterpump

I would expect a few days for shipping. Its as you know a small part...they sell for around $46 Canadian here.<br /><br />I will mention the part # again for you.<br /><br />89984T<br /><br />This should help you out in finding one locally.<br /><br />TMD
 
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