diesel tachometer

Stumpy

New member

Equipment
L175
Dec 1, 2011
848
3
0
NE Ohio
The majority of tachs I've seen on diesels are straight mechanical. There is a spinning flexible shaft inside the cable that runs to the gauge which turns a magnet. Another magnet connected to the needle moves an amount determined by the strength of the field generated by the first magnet which is determined by how fast it's spinning. The take off from the engine can be anywhere depending on the gauge and how it's graduated. The one on my L175 is attached to the fuel cam shaft. The one on my Honda Nighthawk (motorcycle) is driven by a gear off the crankshaft.
 

sidwell50

New member
Jan 10, 2012
17
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0
Yakima Wa
I have a Kubota v2203 engine from a Carrier refrigeration unit for a semi trailer. I am installing it on my boat. I want to know the engine RPM so I don't over load my transmission.
 

Stumpy

New member

Equipment
L175
Dec 1, 2011
848
3
0
NE Ohio
Hummm. I'm not sure you'll be able to find/make a mechanical tach cable long enough to do that. The best option I think would be to find a marine aftermarket unit that uses the alternator frequency as it's source. Minimal fabricating and setup is pretty much plug and play.

Unless someone has a source on long length mechcanical cables that'd be the route I'd go.
 

kuboman

Member
Dec 6, 2009
725
4
16
Canada
There are lots of electric tachs that will work for that application. You just have to mount the sensor so it will count the teeth on the flywheel and run a wire to your tach.
Or some just need a small piece of reflective tape mounted on the flywheel.
 

Kytim

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B6000DT, B7100DT,Snowplow, RM360, Scoop, Cultivator, Carryall,Disk, plow
Aug 14, 2009
848
9
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Western Ky
theres also mini-tach that counts the fuel pulse from the sensor placed on the line to the injector. simplest solution i think. i think their website or maybe here has a install demo on a kubota engine.
 

Tweetybrun

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Equipment
L 3200 Tractor Loader B/H RTV x1100c Grand L 4060 FL 805, BH 9.2
Jul 28, 2014
69
0
6
Hancock New York
Good afternoon, I have an L3200 2015 would you know if the tach cable is a spinning shaft or something different? Mine stopped working wit h the hour meter. I am afraid a mouse got in there.
 

steve

Member

Equipment
B7100HST, B5001DT/B5100DT, JD-111H, Chevy K2500 DuraMax, CJ-5, CJ-7, TJ jeeps
Feb 17, 2009
51
1
8
Henniker. NH, USA
I just got a diesel tachometer that uses a magnetic pickup to drive it. I'm planning on using the ring gear on the flywheel for the pickup to read. My question is how many teeth on the ring gear of a B5100 with a Z500 engine? I need the info to calibrate the tach.
 

GeoHorn

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M4700DT, LA1002FEL, Ferguson5-8B Compactor-Roller, 10KDumpTrailer, RTV-X900
May 18, 2018
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My JD4329 engine runs it's tach via the field output of the alternator. (Counts the revs knowing the pulley-ratios.)
 

steve

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Equipment
B7100HST, B5001DT/B5100DT, JD-111H, Chevy K2500 DuraMax, CJ-5, CJ-7, TJ jeeps
Feb 17, 2009
51
1
8
Henniker. NH, USA
Found a picture of a flywheel on Ebay and counted 98 teeth
 

North Idaho Wolfman

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L3450DT-GST, Woods FEL, B7100 HSD, FEL, 60" SB, 743 Bobcat with V2203, and more
Jun 9, 2013
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Sandpoint, ID
I just got a diesel tachometer that uses a magnetic pickup to drive it. I'm planning on using the ring gear on the flywheel for the pickup to read. My question is how many teeth on the ring gear of a B5100 with a Z500 engine? I need the info to calibrate the tach.
Mind sharing what tach you have gotten? ;)