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  Topic Review (Newest First)
06-05-2013 08:38 AM
Re: Yanmar tach reads low rpm

I recently put a Faria tach in for my Yanmar 44; it reads fine to about 2400 RPM, then goes in reverse (showing lower) RPM as I increase throttle.
No calibration adjustment, just number of teeth (correctly set for 127).
Unlike the diagram I have a 'stbd sync' and a 'port sig' connection, both of which are connected.
Drives me nuts.
06-04-2013 05:11 PM
Re: Yanmar tach reads low rpm

Aaaahhh...... Thanks
06-04-2013 04:13 PM
Alex W
Re: Yanmar tach reads low rpm

I think that schematic is for a Teleflex tachometer, not necessarily the stock Yanmar one. Look at who produced it.

My Yanmar tach has a fixed setting for number of teeth. It is written on the face of the tach (something like P=127).

Thanks for copying the image over!
06-04-2013 12:35 PM
Re: Yanmar tach reads low rpm

The schematic of course stops before getting into the tachs inner workings...anyone have any insight if I do try to disassemble the tach what success I may have in adjusting the rpm readout and then reassembling in working order?
06-03-2013 09:14 AM
Re: Yanmar tach reads low rpm

Thanks for the tach schematic...I wonder if some tach disassembly is required to get at the 'range selector switch' and the 'calibration' screw.
Looking at the back of the tach as it's installed in the engine control panel, it looks as if maybe the 'body' could be removed as it may be covering/protecting the adjustments that may be the culprit.....
If the 'range selector switch' is set to the wrong tooth count range - seems like it would cause a large error in reading accurate rpm.......
Anyone disassembled a tach before?
06-03-2013 08:27 AM
Re: Yanmar tach reads low rpm

Hope this photo comes through.
06-02-2013 11:03 PM
Alex W
Re: Yanmar tach reads low rpm

Ugh, the IP forum requires me to have an account to read that webpage. Would it be a lot of work for you to cut and paste the useful post?
06-02-2013 05:08 PM
Re: Yanmar tach reads low rpm

This may be enlightening; its from the Island Packet forum:
06-02-2013 12:40 PM
Re: Yanmar tach reads low rpm

Your pickup is for a 1GM. If not for a 1GM, it's the wrong one.
06-02-2013 11:46 AM
Re: Yanmar tach reads low rpm

could be as simple as a corroded wire/conection. Otherwise, bad pickup or tach
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