I do my own lawn equipment motor repairs myself. So lately I have been thinking and it would be good for me to have a good means to check the rpms on some of this equipment. I know I can buy an Ebay or amazon tach that you wrap the pickup around the plug wire but not sure if this is the correct way to go. So, question is what do you real world repair people use? If you all feel that the inexpensive ones are good enough than I would go that way, they just seem to be hokey. Because of having 2 and 4 cycle plus single to twin cylinders the inexpensive ones you have to keep changing the info to get the proper rpm readings. I don't think I would need to spend $300.00 to get something that would work for my use. Thanks Maybe I am just over thinking this.
Maintenance Tachometer
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4getgto
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I've used this type for the last 40 years and servers me well...
Opinions will vary but I feel its about as accurate it gets. And works on any running motor and any given rpm...
Look around as I'm sure it can be bought cheaper.
Opinions will vary but I feel its about as accurate it gets. And works on any running motor and any given rpm...
Look around as I'm sure it can be bought cheaper.
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No you don't have to be constantly changing the settings.
99% or better of small engines uses magnetos with wasted spark. Otherwords the plugs spark every revolution. 1 spark per RPM; be it two cycle or four cycle. Doesn't matter if they one plug or two plugs so inductive tachs are set to to one spark per rev. It only when you start getting into engines that use distributors when you start needing a different setup for measuring rpms. Even then it is usually one per two revs when it is a four cycle engine but that can be different depending where you are taching off the distributor which operates off the camshaft.
It like the old JD 420 here if tach off one of the plugs then use one setting but if you are tach off the coil lead then you use a different setting. When you do coil lead it fires the number cylinders per rev of the distributor. Otherwords the cylinder engine would be reading double on meter than the actual rpm or vica vesa. I never really got into that area with any of my tachs here.
As in shop RPM checks I have use Tiny Tach inductive meters but currently I using a Husqvarna/Echo tach to these tests. Note that I rarely check the rpm on anything other small engines.
Now if you plan to leave the tach on the engine then wrapping the pickup lead to one of the plugs is best.
99% or better of small engines uses magnetos with wasted spark. Otherwords the plugs spark every revolution. 1 spark per RPM; be it two cycle or four cycle. Doesn't matter if they one plug or two plugs so inductive tachs are set to to one spark per rev. It only when you start getting into engines that use distributors when you start needing a different setup for measuring rpms. Even then it is usually one per two revs when it is a four cycle engine but that can be different depending where you are taching off the distributor which operates off the camshaft.
It like the old JD 420 here if tach off one of the plugs then use one setting but if you are tach off the coil lead then you use a different setting. When you do coil lead it fires the number cylinders per rev of the distributor. Otherwords the cylinder engine would be reading double on meter than the actual rpm or vica vesa. I never really got into that area with any of my tachs here.
As in shop RPM checks I have use Tiny Tach inductive meters but currently I using a Husqvarna/Echo tach to these tests. Note that I rarely check the rpm on anything other small engines.
Now if you plan to leave the tach on the engine then wrapping the pickup lead to one of the plugs is best.
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Do I do not want to leave any one of the options on the units I plane to use it on different motors at different times as needed. Thanks, for the replies and I still am debating on the options people have been using.
bertsmobile1
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I Bought a TinyTac inductive unit as well
The shop came with an Inductive dial tach, I use that a lot as well but it is big & clunky where as the TT sits in my pocket .
The dial display is good for things that fluctuate a bit like a chain saw that dose 12,000 rpm, hard to get a handle on that with a digital tach
I also have a reflective tape laser tach I use for lathe work because the original speed decal had worn off the small one & a change or motor on the big one caused it's plate to be wrong but at $ 500 ( aus) a bit expensive for mower work .
The shop came with an Inductive dial tach, I use that a lot as well but it is big & clunky where as the TT sits in my pocket .
The dial display is good for things that fluctuate a bit like a chain saw that dose 12,000 rpm, hard to get a handle on that with a digital tach
I also have a reflective tape laser tach I use for lathe work because the original speed decal had worn off the small one & a change or motor on the big one caused it's plate to be wrong but at $ 500 ( aus) a bit expensive for mower work .
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The one that I use from Husqvarna seems to do a good job @ 12K. My Tiny Tach II did a fairly good job at 12K too, just the battery failed as it on all the time instead of stand by like the Husqvarna tach.
It depends on what you want to measure?
I got a mechanical/photo tachometer. Then I don't need to have any ignition or electrical connections and I can do stuff like PTO/shaft rpm's or electric motor speeds. I have some stuff that it's very difficult to get to anything so access is a major problem. Interestingly it also can measure surface speed for say a sanding belt. The photo part can read to 100K rpms and the mechanical section can read to 20K rpms.
I have an Extech Model 461895. Way too expensive new at around $266! BUT I shopped used on EBay and they are much cheaper. Usually you can find one under a $100.
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I got a mechanical/photo tachometer. Then I don't need to have any ignition or electrical connections and I can do stuff like PTO/shaft rpm's or electric motor speeds. I have some stuff that it's very difficult to get to anything so access is a major problem. Interestingly it also can measure surface speed for say a sanding belt. The photo part can read to 100K rpms and the mechanical section can read to 20K rpms.
I have an Extech Model 461895. Way too expensive new at around $266! BUT I shopped used on EBay and they are much cheaper. Usually you can find one under a $100.
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Castleford
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I have an old photoelectric tach from days past that I used on model airplanes. Never sold it or threw it out, it comes in handy for measuring engine speed at the flywheel as long as I mark it properly...