2310D Tachometer Inaccurate

tonyg2160 · Apr 8, 2018

4get gto said:
I'm thinking you can check the cable and tech just by taking it out at the motor and putting a drill on it. That's if it's not the gear drive on the block.

GOOD IDEA! ;-)

tonyg2160 · Apr 8, 2018

Good idea on the drill GTO. I took the cable out from the engine end and put it in a cordless drill. (FYI..be careful not to chuck it up too tightly or you'll "pinch" the gap in the end together). Apparently something in the gauge itself was bound up a bit, or sticky or something. I ran the drill a bit (in reverse to "increase rpms on the gauge) and it went up to 1200 or so. I then ran it "backwards" for a bit, then forward, back and forth for a while, and the max rpm's on the gauge gradually increased. Finally maxed out at 2400-2500 rpm (which I suspect is the max reverse rpm of my drill). Put it back together and seems to be good now! ;-) Now...I would like to get a comparison reading somehow. Any suggestions on pulling a comparison RPM reading? Harmonic? Optical? Electrical?

California · Apr 8, 2018

It shouldn't hurt anything to run the engine up to maximum governed speed. That's maybe 2800 rpm depending on model. If the tach shows 2800 and the engine wont go faster - it all checks out.

tonyg2160 · Apr 8, 2018

California said:
It shouldn't hurt anything to run the engine up to maximum governed speed. That's maybe 2800 rpm depending on model. If the tach shows 2800 and the engine wont go faster - it all checks out.

Good to know! I was wondering how "high" it would run up to. I got it up to maybe 2300 or 2400 out there a bit ago, but it wasn't "maxed". Also ordered an optical/laser tach so I can verify this week.

kenmac · Apr 8, 2018

Right after buying mine. The gears locked up and kept breaking the cable. I got a new warranty tach. See if you can get some lubricant in there

Kernopelli · Apr 9, 2018

tonyg2160 said:
............ Also ordered an optical/laser tach so I can verify this week.

Good tool to have, you will find more uses for it than just this particular issue. My "uncle" gave me his old digital Schimpo DT205 after he retired and I have used it far more than I ever anticipated I would. As cheap as the new non contact tachs have become, I think it's one of those tools that everyone that does his own mechanic work should consider having.

California · Apr 9, 2018

tonyg2160 said:
... ordered an optical/laser tach so I can verify this week.

I still have the pre-electronics Briggs & Stratton 19200 Tachometer. Its a simple pocket device, you turn its dial until resonance shows the engine speed.

Here's a video.

Briggs and Stratton (Treysit) Vibration Tachometer - Honda GCV16 RPM Measurement - YouTube