Tachometer troubles

Discussion in 'Engines and Propulsion' started by Weasel, May 18, 2019. Add this thread to a FAQ

  1. Weasel

    Weasel

    Joined May 23, 2004
    121 posts, 2 likes
    Beneteau 331
    US Iuka, MS
    Hi everyone!

    I have a problem with my tachometer. The tach needle does not move when the engine is running. I checked the connection on the engine, even cleaned up the spade fittings. Then went topside and checked the voltage to the tack. According to the Yanmar manual those are the two big checks. I don’t have the equipment to perform a “synchronisation check. Any thing else anyone can think of or am I just going to have to bite the bullet and order a new one? Btw, does anyone know how much a tach costs for a 3Gm30F yanmar, ( ball park is ok)!

    Thanks,
    Weasel
     


  2. Calif. Ted

    Calif. Ted

    Joined Jun 8, 2004
    2,215 posts, 186 likes
    Catalina 320
    US Dana Point


    Weasel likes this.
  3. Weasel

    Weasel

    Joined May 23, 2004
    121 posts, 2 likes
    Beneteau 331
    US Iuka, MS
    Thanks Ted. I think I am just going to have to get a gauge, but I will check some of the items in the information..

    Best,
     


  4. Calif. Ted

    Calif. Ted

    Joined Jun 8, 2004
    2,215 posts, 186 likes
    Catalina 320
    US Dana Point
    You might get lucky, I once had a BO fuel gauge I assumed was the sending unit (PITA) and it turned out to just be the gauge. I think the needle should bounce a little when key turned on and indicates bad gauge if not.
     


  5. SFS

    SFS

    Joined Aug 18, 2015
    1,617 posts, 528 likes
    Hunter 31
    US Tampa Bay
    When mine died (yanmar 3ym20) I checked all the connections (I thought) by tracing the wires through the sole, to the alternator. Somehow, I missed a wire running to the top of the engine, unrelated to the alternator. It had a round terminal that went over a threaded post, with a washer and a nut. The nut had backed off. A 4-second fix, once I found it. I don't have a picture, sorry.

    Edit: I may have started a thread at the time, with pics. Search my posts, keyword "tach", between March 2018 and July 2018. Hope this helps.
     


  6. Benny17441

    Benny17441

    Joined May 24, 2004
    5,764 posts, 420 likes
    CC 30
    US South Florida
    When mine died, I realized I really never had any use for it; I had used my hearing and the seat of my pants all along. At over $500 I realized I could live without it.
     


  7. kloudie1

    kloudie1

    Joined Nov 6, 2006
    8,320 posts, 765 likes
    Hunter 34
    US Mandeville Louisiana


  8. dennismenace111

    dennismenace111

    Joined Jul 26, 2015
    41 posts, 9 likes
    Watkins 29
    US Ft. Lauderdale
    I have aasimilar problem. My old tach had visible moisture in the lens. Like a cheap wristwatch that you forgot yo take off before jumping in the water. I just bought a Faria tach that works with a magnetic pickup on the fly wheel...$74.00 on eBay... Search eBay for a FARIA BEEDE 32803 FARIA EURO BLACK 4" TACHOMETER 4000 RPM DIESEL MAGNETIC
     


    nfg2u and Rick D like this.


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