How do you test a rev counter ?

[SpottyDog5]

My rev counter not working on my rib, it has Mariner 25hp outboard.
Can it be tested with a multi-meter?
Any advice please.

 

[jimboooo]

hi mate , sorry its not really an answer more a comment , i had my rev counter set correctly on its last service , the speed v revs v speed just wasn t adding up . I belive some counters can be fiddled with and adjusted at the rev counter end .

 

[SpottyDog5]

Hi Jimboooo
Thanks for the post, at least you bought the post back up to be viewed again by the forumites, I had hoped for a bit more response on this.
Cheers Buddy.

 

[elton]

You can use a multimeter on 20V DC range, between ground and the rev counter input to check if a signal is getting there from the ignition circuit. The displayed voltage should rise with revs. If there's no voltage, check it at source (the ignition ciircuit). If you have a signal at the source but not at the rev counter, check the continuity of the connection with the multimeter on Kilohms range (and everything turned off). If it's a digital rev counter, you should also check the supply voltage.

 

[SpottyDog5]

Thanks Elton, Just what I needed to know.
cheers

 

[ulyden]

Easiest way is to borrow a optical tachometer and compare.

Else you can use a frequency(Function) generator to make signals to the tachometer.
Then you need to know the number if pulses per rev you get from the engine!

A skf tachometer looks like this!

http://www.skf.com/files/100184.pdf

A fFunction generator loks like this!

http://www.teknetelectronics.com/Search.asp?p_ID=18664&pDo=DETAIL&Fluke_PM5136

 

[snooty fox]

get one of these and check the circuit.

http://www.maplin.co.uk/Module.aspx?ModuleNo=46449

 

[SpottyDog5]

Thanks,that looks interesting.
cheers

 

[Refueler]

Ebay ... Hand Held Optical LED rev counter .... less than a tenner ....

QED