How to Use This Device to Measure Dwell and RPM's

Bulbash

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May 22, 2012
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Guys,

I acquired this device for measuring dwell and rpm's. Now it might be a stupid question, but how would I measure dwell and rpms. If you look on the picture when it is on and probes are not connected to anything it still reads a value, is this the way it supposed to be?
 

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alldodge

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That looks like a volt ohm meter, and if that's correct your not going to read dwell. Cannot make out the dial and button names
 

Bulbash

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May 22, 2012
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Sorry for the unclear picture. This meter has dwell settings for 4,6,8 cyl and same for rpm's. The only questions is where do I attach the probes to?
 

Bulbash

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May 22, 2012
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So just so I understand it right:
1. Remove cap rotor and etc to access points
2. Adjust points with filler gauge
3. Connect Dwell meter to coil, positive probe (red) to coil output or positive small wire on the coil? Black on any good ground?
4. Turn ignition ON without engaging starter to read dwell angle
5. Adjust points with ignition ON until correct dwell angle is achieved?

Does this looks correct?
 

Schtoopid

Petty Officer 3rd Class
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Jul 23, 2016
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Wow, long time since I did dwell on an engine.
Yep, gotta be running. I think one line to the lead from the points, one line to ground. But its been 30 years since I did one.
 

dennis461

Chief Petty Officer
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Aug 11, 2011
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516
If you get it working...
Please post up the manufacturer make/model of the meter.
On my old boat, the HV ignition coils and points operation makes a digital meter go crazy.
I have always used the analog meters I own to read dwell.
 

bruceb58

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Mar 5, 2006
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BTW.....you can get a reading of dwell with the distributor cap off by just cranking the engine. There will be a slight offset so measure the dwell while the engine is running and then while cranking with the distributor cap off to see what that offset is. Then you can adjust the points little by little with the distributor cap off to the exact spec +/- offset
 

Maclin

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May 27, 2007
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Also there are two measurement units, one is percent and the other is degree (angle). Most older dwell meters have a scale on the back to convert, with different lines for number of cylinders.
 

Maclin

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May 27, 2007
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6,761
Just need distributor to be spinning at a good cranking rpm. For cars (dating myself now) we would do this on a distributor machine with distributor out of the engine, could get points set exactly. Also could spin higher and check the mechanical advance curve, pre-electronics era.
 

boobie

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Nov 5, 2009
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20,826
The one we had in our shop you could also check the vacuum advance.
 
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