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Yamaha Ebbtide 3.0L water pump/overheating issues

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  • Yamaha Ebbtide 3.0L water pump/overheating issues

    I have a 1993 ebbtide Yamaha 3.0l. I had it winterized last year, then the same place claimed to have put it back together. On my run from the public access back to the house, it started to run really hot. Noticed there was a hose dangling down under the engine with water coming out of it, and it apparently was part of the exhaust system. As I hooked it back up, the rubber exhaust bellows started smoking and eventually melted. The hose ran to the back wall into the transom.

    I have looked for the last 6+ hours trying to find info about this boat, but it all seems pretty limited since Yamaha didnt make their engines very long. I would love to find a service manual, but they seem to not exist. I am a pretty decent automotive mechanic and have grown up on the water, but have only ever owned outboards until this boat.

    So my question is, what could I have messed up by not having that hose connected? I am overheating any time I run (i replaced the bellows thanks to some serious ebay searching), and it seems like I am not pushing water properly. I dont even know where to start. I dont want to take it back to the place that winterized it, as I seem to have nothing but problems with them. I want to fix it and then make them pay for the parts if at all possible.

    Any suggestions? Other threads I should read? Please help! Thanks peeps
    Last edited by Detra319; May 23rd, 2017, 09:58 PM.

  • #2
    Ayuh,..... Welcome Aboard,..... For lessons in boat mechanicin', especially for auto mechanics,....

    Click the link in my signature, Don'S Adults Only Section,....
    It's packed Fulla stuff ya need to know, 'n things you'll understand,.....

    Boat motors need 2 water pumps,...
    The usual circulatin' water pump, just like on a car,....
    A raw water pump to pump raw water into the boat's motor,... raw water is expelled with the exhaust in the risers,...
    The raw water pump is a rubber impeller pump, either mounted in the lower unit of the drive, like a Merc Alpha,....
    Mounted on the motor, like the Merc Bravos,....

    I donno squat 'bout Yamahas, as there's so few of 'em,...
    I donno whether it's a drive mounted pump, or motor mounted,.... I Believe the latter,...

    The hose ya found is either the in-comin' line from the raw water pump in the drive, which would normally go to the t-stat housin',...
    It's the pickup hose for the motor mounted raw water pump,... in which case, it'll go to the raw water pump,...

    If it's a motor mounted raw water pump,....
    You no doubt smoked the impeller to bits, from runnin' it without water,... they die very quickly without water,...

    Good Luck, 'n We'll be here for ya,.......


    • #3
      Ok thanks alot! Im going back up north to our summer place here in a week or so and I will start ripping things apart. Do you have any idea who I should talk to about getting a basic engine diagram for the Yamaha 3.0? I have been digging around but cant find anything about the 4 cylinder versions. Thanks! I really appreciate your time, Im trying to save my old man some money as no one seems to know anything about this engine up here in the frozen north.


      • #4
        Ayuh,.... The long block motor is exactly the same as Merc, OMC, 'n Volvo 3.0l motors, built by GM,....

        It's all the accessories from Yamaha that's different,...

        Yamahas were only imported a couple of years,....
        My best advice is, get it runnin', 'n Sell it,....

        Parts are nearly non-existent,...


        • #5
          Alright, so I dont know the difference between the raw water pump and the circulating pump. Are there 2 water pumps on this engine? Every search I use turns up a raw water pump only. Can I take this one apart and expect to be able to put it back together without having to replace any seals/gaskets? It seems pretty basic to me, but I am really only a car guy as I have said.


          • #6
            Ayuh,.... There are 2 water pumps on most of the I/Os, 'n inboards,....

            The circulatin' water pump is exactly where, 'n like seen on car motors,...

            The raw water pump is a rubber impeller pump that moves outside the hull water into the motor's coolin' system,....
            It's mounted inside the outdrive on many, but belt driven on the motor for others,....

            Ya Plan on doin' a rebuild on it when ya pull it,... New impeller, 'n gaskets is minimal,...

            I've never even seen a Yamaha like yers, which is why I'm bein' vague,.... sorry,...


            • #7
              Ok, so the kit is $100+ for the rebuild kit. So maybe first I should get a manual. Does the Clymer manual for 89-91 yamaha 3.0 sterndrive cover this even though its technically listed as a 1993 ebbtide? They only made these engines for 3 years, right?


              • #8
                Does the Clymer manual for 89-91 yamaha 3.0 sterndrive cover this even though its technically listed as a 1993 ebbtide? They only made these engines for 3 years, right?
                Ayuh,.... No Clue,.... Never seen the manual or the drive/ motor,....

                I think they're still makin', 'n sellin' 'em everywhere but the America's,....

                Only imported to the US for a couple years, yes,... parts are scarce,... best advice is to detail it, 'n sell it while runnin' right,...


                • #9
                  I purchased a Yamaha sterndrive service manual on Ebay. It has a pretty good diagram on the cooling system. I can scan the page for you when I get home this weekend if you like. My Yamaha is a 4.3 and the raw water pump is on the front port side at the bottom of the motor. I believe your 3.0 is located in the same general location. I have had this particular boat a short period of time and I am beginning to believe what Bondo is saying. Get it running and sell it. Parts can be located from Nelson Marine Service, in Florida. www.nelsonmarineservice.com The owner is really knowledgeable.

                  Hope this helps a bit.


                  • #10
                    Post some pictures of the engine; sides, front, rear etc. It may be easier to tell you what the things are than trying to explain where they're at.


                    • #11
                      Ok, so I went and purchased the manual because why not? So, I found the raw water pump and the circulating pump thanks to the diagram. Pulles the raw water pump and the impeller is shot. 100% no arms left on it. So, ordered another one that I dug up on another thread that said I could use a Jabsco replacement for $30 instead of $100+ like the actual replacement is. We will see. I had my dad bring the boat back south (his place where it summers is 6 hrs north) so I can look at it myself.

                      So now I come to the part about what do to do about finding the broken impeller pieces. I dont have a power steering cooler, so they cant be there. Is there a written procedure or post about how to backflush these 3.0s? Can I pull the thermostat and housing without having to replace the seals or gaskets?

                      How do I check the circulating pump to see if it went bad? Do i have to pull it to check it? When I google it, it keeps popping up Sierra replacement for the circulating pump. It looks the exact same as the one in the engine based on the pictures. It doesnt appear hard to remove, but again we come back to the part about gaskets and seals. Will I need to replace those?

                      You guys are awesome, thank you for the help. I have been trying to learn everything I can about this boat as my dad seems bound and determined to keep it and not buy another. Wish me luck!


                      • #12
                        Ayuh,.... The odds are the ole impeller bits are hung up in the t-stat housin,..... Yes, ya need the gaskets,.....

                        The circulatin' water pump is probably alright,... they leak water 'round the shaft when they go bad,....


                        • #13
                          Just a follow up on this guy since ya'll gave me so much help. The raw water pump was belt driven and only 2 bolts to take off. Very easy. The impeller inside the pump was shot. I spent literally hours on the net trying to find one, only to eventually order a $115 replacement. Well, after it got here I looked on the old impeller and it was a volvo penta impeller, and it sells for $13! I will post the part number here later, but that will save you a ton of money if it ever happens to anyone else. The bits were actually stuck all the way at the back of the exhaust where the water flows back out.

                          Edit: Volvo Penta Impeller 825940

                          Its 12.95 on walmarts website. Ha!

                          Now if I could figure out this cavitation issue where she starts to skip a little at max throttle...
                          Last edited by Detra319; July 8th, 2017, 04:07 PM.


                          • #14
                            Its a Sherwood SHE R991 pump. I keep a spare in the boat just in case. Those things can got out quick with no warning.


                            • #15
                              Sign up today
                              Sorry I am a little late to the party to probably help you, but the person who advised you of Nelson Marine in Panama City FL is correct. Ken is THE expert on Yamaha Stern drives. He rebuilt my trim pump last year and knows his stuff for sure. In fact helped me just today find a fuel pump switch for my Yamaha 4.3. Yes, as u already know, whoever sold you that impeller ripped you off!! Ok, back to your original issue. I share this from experience in the 4.3... not sure if it's the same on the 4 cylinder or not, but worth telling if it may save you now or in the future... I had an issue a few years ago that had my engine running hot. I was short on time so I took it to a jack leg marina who said they could fix it. Replaced the water pump (like many things on these engines, it's just a chevy pump from napa), and replaced the impeller, still ran hot... AFTER they told me it was fixed. Then they said it was a bad sending unit on the thermostat to the temp gauge, and foolishly replaced that... after I ran it for about 20-30 minutes, I had a funny feeling to check the motor, as the temp needle finally started creeping up a tad... I lifted the deck and the whole engine compartment was FULL of smoke and I couldn't believe the boat was not on fire! It was WAY hot, and completely toasted the paint on the exhaust manifolds. We were blessed the boat didn't catch fire.... anyway, I won't share the conversation I had when I got back to the marina, but here's the bottom line.... the 4.3 has a weird little plastic piece that goes through the transom and a hose connects it to the motor and to the intake on the Stern drive. That piece had dry rotted, and had cracks in it. At idle, it got enough water to idle cool. At higher rpms, it sucked air. I ordered one from Nelson Marine and was eventually back in business. Ken says he would just punch a hole through the bottom of the hull as opposed to pulling the lower unit if he ever had to repair one (so as to prevent the same problem in the future)... good idea actually. So, I'm not sure if you got a busted little plastic elbow in your transom that allowed that hose to come down or not, but I would be willing to be that you do... Get your parts from Ken. He is fair on price and knows what he's doing. I learned the hard way that most do not know about these yamahas. Like Bondo said, they weren't around long enough for people to have seen them very much.
                              Good luck with it!