Tachometer troubles

Weasel

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May 23, 2004
152
Beneteau 331 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
 
Jun 8, 2004
2,841
Catalina 320 Dana Point
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Weasel

.
May 23, 2004
152
Beneteau 331 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,
 
Jun 8, 2004
2,841
Catalina 320 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.
 

SFS

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Aug 18, 2015
2,065
Currently Boatless Okinawa
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.
 
May 24, 2004
7,129
CC 30 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.
 
Jul 26, 2015
42
Watkins 29 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