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Checking RPM's


720nut

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I have 2 Kohler 980's in my Exmark's and would like to know how to check the rpm's on them as one seems to turn a little higher than the other thus spreading cut grass better, if that makes sense.

Anyway was unsure where to ask this but with the knowledge that's on this site I was hoping someone could tell me , been years but my dad had a little hand held tach to use on single cylinder engines 

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I use a combo hourmeter/tach that’s the same size as a regular rectangular hour meter. You wrap the sensing pickup lead around a plug wire.  The battery is supposed to last about 10 years. 
I also have another one (a present) where you cut a piece of reflective tape and stick it to the crankshaft. I’ve only used it once when I compared the readings of the 2 devices which were very close. 
 

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I have a Tiny Tach that I mostly use for tuning chainsaws.  On many of today's chainsaws you adjust the high speed jet to achieve a certain maximum RPM for that saw.  Too fast and it can be burning lean causing piston scoring.  

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Talntedmrgreen

That Fast-Tech sure looks slick.  I use the laser/reflective type for rpm of power transmission stuff...PTO shafts, pulleys, etc.  Those work great for measuring things like blade speed, figuring our ratio changes for input speed differences (just changed a 1000rpm flail mower to 540).  I don't have anything measuring rpm thruogh ignition though, and that would be great.

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5 hours ago, ShaunE said:

I use one of these. 

 

I have one, too. Cheap (like me)

Edited by dhoadley
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