88 skeeter sx 180 intermittent tach. bouncing all ove the place

[schoolboy21]

sometimes while driving my tachometer will either go way high or low without any change to throttle or trim. i've checked my connections at the tachometer itself and at the engine side. just wondering if anyone has ever run  into this before?

[SkeeterMatt]

mine does the same thing... i wish someone would post an explaination.

[clarker2000]

I would guess at as long as your engine isnt reving in a strange way then your fine.  As far as the problem it sounds like you may have a loose connection somewhere else like in the engine.  Call a local tech and IM sure they will help.

[larry matthews]

check out all ground connections, had the same problem and the mech that I use showed me the ground strap was loose on the outside of the cowling.

[bassadict69]

Mine once did the same thing...on the back of the tach, there is a small setting dial. Make note of the setting then with a small screwdriver, turn that dial back & forth a couple times then put it back on its original setting.

I did this off & on for a little over a year...It would act up, I would do this & it would work fine for a couple months then start acting up again. The bad news is that eventually it quit working all together!

[BigDBasser]

check out all ground connections, had the same problem and the mech that I use showed me the ground strap was loose on the outside of the cowling.

Larry is right on with this one.  9 out of 10 times, it's a grounding issue.  The way to fix it is check all your ground connections thru out the boat.  Somewhere a ground is loose or corroded.  It's a pain in the butt, but if the bouncing needle bothers you that much, that's what you have to do. 

[bass11.11]

If your running a Mercury it may be your regulator/rectifier.  Switch the tach wire to the oposite regulator grey wire and see if it quits.  Mine did the same thing and I ended up replacing the R/R with CDI units and problem solved.  My motor is a Mariner 135hp.

[iClass]

I agree with the ground wire. Corroded or breaking. A good tech can track it down pretty quickly.