Checking RPM
Dirt don't hurt
Joined: Jan 2011
Posts: 21,065
Likes: 4,561
From: Haslet Texas
Do you have a link to a multimeter like the one you have?
Elite HDF Member
Joined: Jan 2006
Posts: 4,344
Likes: 67
From: Hooterville, Fl.
Road Master
Joined: Oct 2011
Posts: 957
Likes: 2
From: Carlsbad Springs Ontario
Go to any auto parts store , they will have a motor testing tach. that is much less expensive than a multimeter with this feature. I think i paid around 20 - 30 bucks for mine . They have only two connectors , one for ground and the other receives pulses from your low voltage connector at the coil. Can be set for 2 - 8 cyl. motors . Be sure to follow the directions in the handbook.
Elite HDF Member
Joined: Jan 2006
Posts: 4,344
Likes: 67
From: Hooterville, Fl.
Go to any auto parts store , they will have a motor testing tach. that is much less expensive than a multimeter with this feature. I think i paid around 20 - 30 bucks for mine . They have only two connectors , one for ground and the other receives pulses from your low voltage connector at the coil. Can be set for 2 - 8 cyl. motors . Be sure to follow the directions in the handbook.
Stellar HDF Member
Joined: May 2009
Posts: 2,856
Likes: 127
From: Middle of Kansas
I never thought about it before, but I have a tach that reads the prop on my model airplane engines to check rpm. Since it reads two prop blades I would think I could hook up my timing light to the front cyl, and since my stock ignition fires both cyl every revolution, I should be able to use it to check rpm on my Harley by pointing the tach at the timing light. Since I am the curious type, I will have to try it to see if it will work.
Road Master
Joined: Oct 2011
Posts: 957
Likes: 2
From: Carlsbad Springs Ontario
Deep Purple
Machinehead (the Deep Purple guy) LOL is correct. There are less expensive ones out there that will do what you want. Texas Hill country wanted to see one like mine so that is the one I posted. One of the most handiest gadgets to have around the house. Use it all the time in the house, on the bike, on the trucks, etc.
Have you noticed that Ozzie has let his wife get all the air time lately ?
Could not beleive he went for this reality show ??
What is the world coming too ...!?
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Stage I
Joined: Jan 2021
Posts: 1
Likes: 1
From: PA
Well this is late, but maybe it'll help someone out.
There's an app (Android only) designed for measuring idle speed from the exhaust sound. It's $0.99.
Video:
Play Store: https://play.google.com/store/apps/d...m.cma.idleTach
You could also try an inductive tachometer from amazon or ebay. They cost about $10-$15. They have a wire that wraps around the spark plug wire and picks up the signal each time the spark plug fires. From my testing it seems that the single fire carbureted sportsters use multi-spark at low RPM, so make sure to choose the right setting. It should be easy to figure out based on the reading and what it sounds like.
There's an app (Android only) designed for measuring idle speed from the exhaust sound. It's $0.99.
Video:
Play Store: https://play.google.com/store/apps/d...m.cma.idleTach
You could also try an inductive tachometer from amazon or ebay. They cost about $10-$15. They have a wire that wraps around the spark plug wire and picks up the signal each time the spark plug fires. From my testing it seems that the single fire carbureted sportsters use multi-spark at low RPM, so make sure to choose the right setting. It should be easy to figure out based on the reading and what it sounds like.
