Guests - If You want access to member only forums on HSO. You will gain access only when you Sign-in or Sign-Up on HotSpotOutdoors.

It's easy - LOOK UPPER right menu.

Sign in to follow this  
Followers 0
slabberknocker

75 merc

14 posts in this topic

I have a 75 horse merc that I have a problem with. The last time I took it out, there was hardly any water comming out of the hole. Could moss have gotten into the jets or is there a pump that sucks the water in and could that have gone out? I dont know much about motors so I figured I could get a good answer here.

Thanks

Share this post


Link to post
Share on other sites

Any idea what one of those cost? How hard to install? I just talked to a place in Delano and said that the pump would cost 26 dollars and 225 dollars to install. Does this sound right?

Thanks

Share this post


Link to post
Share on other sites

I am sure others here have a better idea of the specifics for replacing the water pump.

I have never worked on a boat motor, but I believe the water pump is basically a paddle wheel. It is not uncommon to have to replace it every couple of years. I think most manufacturers suggest replacing it every couple of years whether it needs it or not. As far as the labor required, I think the lower unit needs to be removed to replace the water pump.

Call a couple of other marine/small engine repair shops to find what a reasonable quote for labor is.

Share this post


Link to post
Share on other sites

Slabberknocker first thing to check is the tattle tail hose. Remove it from the top of the water jacket and see if you can blow air in it. This has happened to me twice the first time there was a seed pod blocking the tube the second time was two weeks ago on gull and it was a chunk of ice.
Mike

Share this post


Link to post
Share on other sites

How old is the motor?
First check the hoses as stated above, I had a wasp once build a nest in the discharge hose in a 65 Merc.
Merc suggests changing the impeller every 2 years, but for most I think this is a little excessive. I change mine in my two motors every 3 or 4 years. Once you do one, it's easy to do if you have the Merc Factory Manual which you should order from your dealer. It takes me about 1/2 day to do 2 motors, and that includes changing the oil in the lower housing (which should be done EVERY year) If you let it go to long, the impeller will shred, and the pieces will have to be removed from all the passages in the water system, and the motor head (Been there, done that....not fun).

Share this post


Link to post
Share on other sites

The water pump is easy to change yourself. First thing to check is that the the hose and water intakes are clear. In the case of a worn impellar the flow from the telltale gradually weakens. If stopped abruptly it is more than likely a blockage as the others have noted. You can replace either the impellar or the whole pump. If you pull it apart and the cup is fine ( no scuffs or scratches you can just replace the impellar). If the cup shows wear or damage then it should replaced also. Bear in mind that the cup will show wear in one spot more than the rest of the area. If it should wear all the way thru it will create a knife edge. If it gets to this point it will then destroy the impellar in a matter of seconds. Since there is only 3 bolts to remove the lower unit you should be able to do the job in an hour or less. A couple of tips tho, as you take the lower unit off it is easier to have 2 people so one can lower it and the other one can remove the pitot hose from the eng. It is usually attached with a wire tie. Also put the eng in a certain gear as you remove the l/u then put it back on with the shifter in the same gear. Nuetral is usually the most convenient. This will insure that the shifting pattern stays the same after reassembly. Good luck!!

Share this post


Link to post
Share on other sites

I've had my the water stop or slow to a trickle a handful of times on my 75 Merc. Everytime it was clogged at the exit place. As others have noted, remove the hose where it shoots out water at the back of the motor and make sure the little plastic piece is clear of debris. Everytime I had a few grains of sand clogging it up from running the motor too shallow or trailering the boat. This is a good first step, otherwise the impeller is easy to replace. Good luck.

Share this post


Link to post
Share on other sites

It is the the impeller. The guy told me 26 bucks for the peice and 225 bucks to install. I think he is bending me over because he said it takes three hours to replace. Either I'll try to figure it out myself or can snyone recommend an honest marine repair shop. Thanks for all your help.

Slab

Share this post


Link to post
Share on other sites

A lot of good info folks. I also have a 75 merc and didn't realize I may have to do the same maintenance replacing the impeller. Thanks.

slabberknocker, I hope you have good luck getting your motor fixed and reading for next season.

Share this post


Link to post
Share on other sites

Yeah I figured I was getting screwed pretty good by this guy. The place is Anchor Marine Repair in Delano on Highway 12. I do not know anything about motors. This is my first boat and I dont know anyone with a boat so that they can show me how to winterize it or anything. The help i recieved from you guys is great and saved me $$$$$.
Valv,
I may have to take you up on that offer if I cant get it done. My father-in-law might be able to do it. He is pretty good at mechanical stuff. Anyway good luck at Mitchell there are also some really nice slabs in there. If there is no ice I have had really good luck on the west side in a bay along the road.

Thanks for all your help guys!

Slab

Share this post


Link to post
Share on other sites

Three hours???? He better get another job or take less coffee breaks. Heck, I do one every 5 years or so and can do it in less than an hour on my 60 hp Merc. I'll need to do it again this spring. Just make you get all the bolts undone before you try taking the lower unit off. There's one hidden under the trim tab that I had a hard time finding the first time. After that there in a cotter key that is part of the impeller assemble. Do not lose it as it will fall out as soon as you pull the impeller off.

Good Luck!

Share this post


Link to post
Share on other sites

Do it yourself, I always replace impeller to my motors every spring when I de-winterize, it's a $ 15.00 expense that gives you peace of mind for the whole year. It takes probably 15 minutes to remove lower unit, and 1/2" hour to installe it, impeller approx 15min/12" hour. Borch is right, there is a hidden bolt under trim tab. When you torque water pump bolts don't be too "energetic" since housing is plastic and breaks easy. Also be careful with impeller driveshaft key, it's easy to loose inside waterpump. Honestly is a easy job if you know how to do a little machanical work. If you want to drive south near Faribault, I'll be glad to do it for you, it will cost you maybe some of that Leinenkugel "barley pop" wink.gif .

[This message has been edited by Valv (edited 11-22-2002).]

Share this post


Link to post
Share on other sites

I put a new Impeller on my 75 Mariner a few years back because I had the same symptoms as your explaining. Now I'll be the first to admit that my mechanical skills are lacking so temper my statements with that in mind. For me, changing that Impeller was tough. I have console steering which, from what I understand, makes it even tougher because the long gear that goes down to the lower unit needs to be in the exact position when putting the unit back on. So, I had to monkey around with the throttle because I inadvertently moved this gear. In other words, when your taking the lower unit off, make sure that gear does not move. I struggled with it for about two hours before my neighbor, who is mechanically inclined, came over and helped me finish. I don't know that I would have been able to complete the job without his help. So, in summation, if you can, get someone to help you do this. My experience tells me not to try this on your own.

Share this post


Link to post
Share on other sites
Guest
This topic is now closed to further replies.
Sign in to follow this  
Followers 0