Tach Reading

[Madden]

I noticed that while the boat (60 Merc) is sitting in the garage the Tach sits at 1 then of course when on the water it goes up as you would expect. This leaves me to wonder... when Tach registers 4 is it really 3? (subtact the 1) Another oddity is, when in the garage, if I turn ignition On/Off it settles back to Zero. Is there any cause for concern here? I'd think when at idle it would go to 1? Is the sitting at 1 normal? just a gremlin tinkering with the needle?

As a sidebar, it seems very few folks ever enter anything or participate on this site. A mystery to me when so many are reading the posts that Gene puts out. There has to be a wealth of knowledge and issues we can all learn from, so why such little participation?

[rk_diver]

No problem, it's acting just like it's supposed to. When you turn the motor off the tach won't go to zero. Per my memory it acts like a needle "dampner". If you're driving home the needle may move up or down because of vibration or bumps. When it's off "0" the needle can move both directions, If it's on "0" it can only move in the upward direction because the needle stop won't allow it to go downward. Supposedly this can damage the needle. This has no bearing on tach accuracy. As you noticed, when you turn the ignition key on it drops to "0". At least that's what I've been told/read. Rick

[Madden]

Thanks. That was a great explanation. Now I can rest easy!

[laylaz]

I have a 90hp honda and tach does the same thing...honda runs so quiet...its hard to tell if its running or not

Thanks. That was a great explanation. Now I can rest easy!