2310D Tachometer Inaccurate

[tonyg2160]

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]

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]

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]

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]

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]

............ 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]

... 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

 

[MJBilbo]

Are there replacement tachometers for Yanmars? My YM226D has the needle missing on the tach

 

[Peter 315]

This one is easy to read without glasses EXTECH Laser Tachometer,2 to 99,999 rpm - 1TZP5'|'46192 - Grainger

 

[Kernopelli]

This one is easy to read without glasses EXTECH Laser Tachometer,2 to 99,999 rpm - 1TZP5'|'46192 - Grainger

Reading Glasses Superior Quality 1. To 4. Resin Eyeglasses Men And Women Hot | eBay and Digital Tachometer Laser Photo Non Contact RPM Tach Meter Motor Speed Gauge AME | eBay are more my (SUPER cheap!) style:thumbsup:

 

[Peter 315]

Reading Glasses Superior Quality 1. To 4. Resin Eyeglasses Men And Women Hot | eBay and Digital Tachometer Laser Photo Non Contact RPM Tach Meter Motor Speed Gauge AME | eBay are more my (SUPER cheap!) style:thumbsup:

Its tough getting old....

 

[tonyg2160]

Its tough getting old....

Lol. I lost my "prescription progressive bifocals" one day and told our three boys I'd pay $5 to the one that could find em...they found 12 pairs of generic reading glasses! None of em were my lost pair..LOL

 

[4get gto]

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?

Many many years ago I rolled back the odometer on a motorcycle I had and did it like that !

Wouldn't recommend doing that NOW! Young and dumb then. Also it takes a month and a day to go back a few hundred miles.

 

[clemsonfor]

Are there replacement tachometers for Yanmars? My YM226D has the needle missing on the tach

yes Hoye probably has some. I know they would have used ones from parts tractors at least. Yours is an American model you can can Yanmar USA for one and possibly some old dealer has NOS sitting on a shelf in some small Midwest town.

 

[rScotty]

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

OHMYGOD! That video took me back to school and a wretched weekend homework assignment in engineering school. I still remember the pain. I'm actually sweating as I write this !

It went something like this:

1. Design a mechanical tachometer using Principles of Vibration. Include sketch, working drawings, & all relevant calculations.

That homework gave me such fits and sleepless nights that I remember it vividly 30 years later. I think I barely got a passing grade on it. My design looked like it would work, but the scale needed to be non-linear. Now I know why, but I didn't back then.
rScotty

 

[rScotty]

This one is easy to read without glasses EXTECH Laser Tachometer,2 to 99,999 rpm - 1TZP5'|'46192 - Grainger

Heres a picture of another type of tachometer. I used this in my repair shop. It's a hand-held type that you hold against a rotating shaft. Range is 100 to 4000 rpm.
A beautiful thing about the size of an apple and quite heavy. It doesn't come apart easily so I'm reluctant to look inside. I wonder if it is a mechanical (chronometric type) or the simpler generator/voltmeter type? Based on the fact it doesn't read below 100 RPM and the linear scale I'm betting it is the generator/voltmeter type like most modern tachs. I'll ask Stewart-Warner if I can find them...
rScotty