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Help us before my husband throws our Mercury outboard in the water!

Discussion in 'Ask All Sailors' started by SVMusic, Aug 9, 2018. Add this thread to a FAQ

  1. SVMusic

    SVMusic

    Joined Aug 2, 2018
    71 posts, 13 likes
    Beneteau Oceanis 40cc
    Music us Little River, SC
    We did try changing the the mixture yesterday. And cleaned the filter again as well.
     


  2. SVMusic

    SVMusic

    Joined Aug 2, 2018
    71 posts, 13 likes
    Beneteau Oceanis 40cc
    Music us Little River, SC
    Could you point me in the direction of how to check the coils?
     


  3. SVMusic

    SVMusic

    Joined Aug 2, 2018
    71 posts, 13 likes
    Beneteau Oceanis 40cc
    Music us Little River, SC
    Update:
    Changed the plugs and cleaned the filter.
    Just like it has been in the past, motor started up, and ran well and got up on a plane. Then after 10 minutes, it dies if you accelerate. This happens time after time, seemingly after the motor warms up. After it cools, it can be started again. Rinse and repeat. :banghead::banghead::banghead:
     


  4. kloudie1

    kloudie1

    Joined Nov 6, 2006
    7,906 posts, 542 likes
    Hunter 34
    US Mandeville Louisiana
    Unfortunately, the coils are usually checked by replacing with new. A simple check with an ohm meter will show good because of no heat (assuming that is the problem). Not easy because that stuff is under the flywheel, but not too much of a pain.
     


  5. Brian D

    Brian D Moderator

    Joined Feb 17, 2006
    3,962 posts, 633 likes
    Lancer 27PS
    US MCB Camp Pendleton, Ca KF6BL
    I had the same problem with my Yamaha 9.9 outboard. I was told by everyone to clean the carburetor. I was scared to death to take the carb off for fear of messing something up. But I did so and it worked out great. No issues since. But I read that you had the carb serviced. But you are still having the same issue. The motor boggs down when you increase the throttle. Like I said, mine did exactly the same thing.

    The issue was the jets. My motor has two sets of jets; one for low idle and one for open throttle. I am sure the mechanic correctly inserted and adjusted the jets when he/she put them back in. However, if they are not adjusted correctly then the fuel flow will be restricted.

    I doubt it is a timing issue because that would show up even in idle. A miss here, a miss there. Or overall a rough idle.

    I don't know, but I would take the carb out and remove or replace the jets. Or... check to see if that motor has a specific procedures for adjusting the jets.

    JMHO

    caveat - I did not read all the replies so if this was already mentioned, my apologies.
     


  6. SVMusic

    SVMusic

    Joined Aug 2, 2018
    71 posts, 13 likes
    Beneteau Oceanis 40cc
    Music us Little River, SC
    I am very glad you responded. This is all very very helpful
     


  7. SVMusic

    SVMusic

    Joined Aug 2, 2018
    71 posts, 13 likes
    Beneteau Oceanis 40cc
    Music us Little River, SC
    The captain responded with Oh F@$k! :whoa: That was Helpful, but he just spit out his coffee at the mention of a flywheel!
     


  8. WayneH

    WayneH

    Joined Jan 22, 2008
    631 posts, 97 likes
    Tartan 37
    US Pensacola Shipyard, FL
    Coils. Oh, God. Coils. My 2 stroke Johnson would suddenly bog down and then come back and bog down and come back. We checked the fuel, drained the carburetor bowl looking for water, changed the plugs. I finally pulled the flywheel off and you could see the crack in one of the coils.

    Getting the flywheel off the Johnson was not hard. I don't have a fully stocked tool chest but managed to get it off without banging up the Flywheel or the mechanic. But this was on a Johnson 1964 6hp.

    Your mileage WILL vary.
     


  9. isaksp00

    isaksp00

    Joined Apr 27, 2010
    937 posts, 60 likes
    Hunter 23
    US Lake Wallenpaupack
    You may also want to post this query on an outboard focused forum. I use iboats.com, where they have brand specific sections. Your Merc may be one made by Tohatsu, and there are a few professional mechanics that give a lot of advice. That said, many of the threads I see there where things die at higher speeds after running for a while are temperature related, where some electronic part (as noted in prior posts) fails when it gets hot. If your issue seems to be when the motor is hot (and it may only get hot enough after running at higher RPM for a while) it may be electrical. As noted earlier, when it starts to die position the fuel bulb with arrow pointing up and pump it. If that fixes it (my guess it won't) then it may be a weak fuel pump. At least on my Honda 8, the fuel pump is fairly easy to service or replace.
     


  10. Rick D

    Rick D

    Joined Jun 14, 2008
    6,563 posts, 164 likes
    Hunter Legend 40.5
    US Long Beach, Shoreline Marina, CA
    FWIW, I went through this for two years on 60 hp OB. Turned out to be the fuel pump despite having it rebuilt twice.
     


  11. Brian S

    Brian S

    Joined Nov 9, 2012
    2,335 posts, 146 likes
    Oday 192
    US Lake Nockamixon
    I just fast read through 3 pages, and there have been lots of fuel system suggestions that never addressed a fuel pump, until Rick D weighed in. So, definitely check your fuel pump. On a 70 hp 2 stroke Merc we used to have, the fuel pump could be rebuilt with new diaphragms. On my small 5hp 4 stroke Tohatsu, it was simply a whole new fuel pump that gets bolted on. Of course, with my Tohatsu, it wasn't the fuel pump at all, but it was the new fuel line and fittings I had purchased, mainly the motor fitting creating a very poor seal and sucking air. I used the original motor and tank fitting from the old line with the new line and bulb and I've been good ever since. Plus I have the old, good, fuel pump as a spare.

    Also, there was a great suggestion to try squirting fuel directly into the carb when it starts to die, as a way to determine if it was fuel system or coil. Did you try that yet?
     


  12. Rich Stidger

    Rich Stidger

    Joined Feb 10, 2004
    2,758 posts, 227 likes
    Hunter 40.5
    US 1997 h40.5 Bristol, RI
    Regarding the $300 carb service- A friend who owns a marina and services lots of small outboards tells me that the only successful way that he has found to completely clean a small engine carb is by using an ultrasonic cleaner. He says that nothing else will clean out the small passages that become plugged. This is especially true for the newer 4-cycle engines, but I took his advice and purchased a small ultrasonic cleaner for all of my small engines. I guess what I am trying to say is that even though the carb was serviced, maybe the job was not as good as it could have been. This may not be the first thing to re-check, but I would keep it on the list.
     


    uncledom likes this.
  13. jviss

    jviss

    Joined Feb 5, 2004
    2,842 posts, 324 likes
    Tartan 3800
    US Westport, MA
    I have two of these motors, a 1998 and a 2001. They are very good, and run well, and are repairable. If you give up, I'll buy yours.

    First, the OEM fuel tank is garbage. I had one fail because the clear, vinyl-like pick-up tube shrunk and became loose, probably because of ethanol in the fuel. By 'shrunk,' I mean the wall thickness decreased, and it no longer sealed. I had symptoms like yours. I bought a new fuel pick up assembly for $26, and it worked for a little while until the same thing happened. The only thing that fixed this was buying a N.O.S. metal tank on eBay. I still use metal tanks, and no problems in this department.

    I have had one electronic module fail. Replacing it was easy, and fixed my running problems.

    There is no choke on this carb. It has an integral fuel pump, and a primer. The fuel pump diaphragm and primer parts come with the rebuild kit. A complete new carb $214.41 in 20014. I bought one because I broke one tightening it too hard.

    Throw away the Merc tank. Get a metal tank. If problems persist, consider an electronic module ($162.03 in 2015). Maybe coils, but I have never had a problem with them.

    Good luck.

    p.s. check and change the lower unit oil every year. If it's milky, stop using it, flush it, and rebuild it with new seals. If you ruin the lower unit your options are very limited. It is cost prohibitive for anyone to rebuild it, and a new one is almost as much as a new motor ($1400).
     


    Last edited: Aug 10, 2018 at 7:02 PM
    Pearson 39-II likes this.
  14. Kermit

    Kermit

    Joined Jul 31, 2010
    4,621 posts, 1,806 likes
    Hunter 260
    US Lake Murray Sailing Club, SC
    A gajillion replies. Mine is the only one guaranteed to work.
     


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  15. SVMusic

    SVMusic

    Joined Aug 2, 2018
    71 posts, 13 likes
    Beneteau Oceanis 40cc
    Music us Little River, SC
    Awesome!
     


  16. agprice22

    agprice22

    Joined Aug 3, 2012
    2,067 posts, 385 likes
    Performance Cruising Telstar 28
    US Watkins Glen
    No. Dinghy
     


    SVMusic likes this.
  17. agprice22

    agprice22

    Joined Aug 3, 2012
    2,067 posts, 385 likes
    Performance Cruising Telstar 28
    US Watkins Glen
    I had my Merc 9.9 do a similar thing. It was a fuel feed problem. It idled fine. It started fine. No miss fires. When I would rev it, it would bog and die. The found the bulb was soft. I tried another tank with a shorter fuel hose. It worked fine. I rerouted the original hose, and it worked. The bulb stayed firm. Check all the fuel connections and the hose route before spending more money.

    Good luck!
     


  18. SVMusic

    SVMusic

    Joined Aug 2, 2018
    71 posts, 13 likes
    Beneteau Oceanis 40cc
    Music us Little River, SC
    Thank you!
     


  19. jviss

    jviss

    Joined Feb 5, 2004
    2,842 posts, 324 likes
    Tartan 3800
    US Westport, MA
    I always thought it was "kermit the frog," now I realize it's "kermit the troll."
     


  20. Sumner

    Sumner

    Joined Jan 31, 2009
    5,138 posts, 194 likes
    Macgregor 26S/Endeavour 37 .
    US Utah's Canyon Country
    :plus::plus:
    I'll bet this is it. If the fuel pump has a diaphragm in it, most do, and it is torn it can still pump enough gas at lower speeds, but not keep up at higher throttle settings. It will get worst to the point it might not pump enough for slow throttle openings,

    Sumner
    ==========================================================
    1300 miles to The Bahamas and Back in the Mac...
    Endeavour 37 Mods...
    MacGregor 26-S Mods...
    Mac Trips to Utah, Idaho, Wyoming, Canada, Florida, Bahamas
     


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