Snap-On Dwell Tach

Y-Blockhead

Y-Blockhead

Well-known member
I was given a Snap-On Dwell Tach Model # MT-715 the other day. I was wondering if anyone knows where I can find instructions for it. I Googled it with no love.

Connecting it is pretty straight forward, I am just wondering about the knob on the far right, specifically the "Set" setting? It doesn't have any hard detents, more like a potentiometer. Thanks.

I'm told the dwell angle for a Model A distributor is 42°.

51335521378_857396c31a.jpg
 
When center knob is at "set" adjust right "set" knob so meter needle is in the "set" area on the right side of scale
 
Call Snap-On customer service at 800-424-7226 or email them. Give them the model number of the meter you have, and they will send you a pdf of the manual.
That's what I did (a couple of years ago) for my MT414 and there customer service was top notch.
 
A few comments. From the picture, the needle zero is off to the right of zero. To adjust first take a damp cloth or paper towel and wipe the plastic meter movement cover. Leave damp, this reduces static charge on plastic cover, then with a small blade screwdriver turn the plastic slot near the center bottom of plastic case to zero meter pointer. As it has a set pot that Kurt mentions, there may be a battery inside the unit. Turn unit over and see if it mentions an internal battery. Enjoy the dwell tach meter.
 
Kurt in NJ said:
When center knob is at "set" adjust right "set" knob so meter needle is in the "set" area on the right side of scale
Click to expand...

Kurt, Thanks. That makes Sense. I will do that in the morning. After "setting it" do I turn the pointer to the proper voltage for my car?

GRutter said:
There is a battery inside. Open it up and be sure that there isn't any corrosion
Click to expand...

GRutter. Yes, I opened it up. I replaced the three "C" cell batteries. I cleaned the minimal corrosion.

Herb Concord Ca said:
A few comments. From the picture, the needle zero is off to the right of zero. To adjust first take a damp cloth or paper towel and wipe the plastic meter movement cover. Leave damp, this reduces static charge on plastic cover, then with a small blade screwdriver turn the plastic slot near the center bottom of plastic case to zero meter pointer. As it has a set pot that Kurt mentions, there may be a battery inside the unit. Turn unit over and see if it mentions an internal battery. Enjoy the dwell tach meter.
Click to expand...

Herb, excellent. I wiped off the lens earlier and I think I caused the static electricity! I did try to adjust the meter. I'll try with a damp cloth as you suggest.

Thank you all for your responses. It seems like it is in pretty good shape. The wires have a few cracks in them, I may replace them.
 
But what is the correct dwell for the 'A', guys? I thought I heard Les Andrews say in a YouTube video that 31 degrees was right for a 4 cylinder engine???? A curious mind wants to know the correct number. LOL
 
Rob Doe said:
But what is the correct dwell for the 'A', guys? I thought I heard Les Andrews say in a YouTube video that 31 degrees was right for a 4 cylinder engine???? A curious mind wants to know the correct number. LOL
Click to expand...

Rob, in post #1 the dwell angle was said to be 42°. When checked, 42° equals .020" point gap. 30-35° would be for a six.
 
Last edited:
No change should be done to the gauge by adjusting the screw slot on front of meter. When new batteries are installed and meter is set to "Adjust" turn the dial till it matches the set line on front of meter. As the batteries age the set line may need to be adjusted since the batteries don't deliver the needed current.
 
KR500 said:
No change should be done to the gauge by adjusting the screw slot on front of meter. When new batteries are installed and meter is set to "Adjust" turn the dial till it matches the set line on front of meter. As the batteries age the set line may need to be adjusted since the batteries don't deliver the needed current.
Click to expand...

Thanks, KR500. I didn't have to adjust screw in front of the meter. The needle retured to zero by itself.

I put new batteries in and adjusted to the Set Line. What is confusing is what are the 6v, 12v and 24v positions for?

Since my car is 12v, do I turn the dial to 12v when the middle knob is in the dwell or tach positions? Thanks
 
GRutter said:
Call Snap-On customer service at 800-424-7226 or email them. Give them the model number of the meter you have, and they will send you a pdf of the manual.
That's what I did (a couple of years ago) for my MT414 and there customer service was top notch.
Click to expand...

I just called Snap-On customer service and no luck and couldn't get past the automation.

I am looking for the manual, for a Snap-On folding primary Dwell Meter MT416.

Thank you,

Merc Cruzer
royd13483@aol.com
 

Attachments

  • Dwell 111.jpg
    Dwell 111.jpg
    42.6 KB · Views: 205
I think the 31 dwell is for the original A. And the 42 is for the B cam which is what all the venders sell now.
 
Looks self explanatory to me. Decide which RPM range desired, then select 4,6 or 8 cylinder engine. Bob's your uncle.
 
katy said:
Looks self explanatory to me. Decide which RPM range desired, then select 4,6 or 8 cylinder engine. Bob's your uncle.
Click to expand...

Found one on e-bay for $35, to include shipping. Got it today, you are correct, is it pretty much self explanatory.

I replaced a few bad wires, then removed the works, and sanded the case and primed it. Will repaint it tomorrow.

The first thing I did was the 9 volt battery test, to confirm it worked. Great idea!
 

Attachments

  • Dwell 111.jpg
    Dwell 111.jpg
    42.6 KB · Views: 16
  • Dwell case 1.jpg
    Dwell case 1.jpg
    38 KB · Views: 14
  • Dwell case 2.jpg
    Dwell case 2.jpg
    62.1 KB · Views: 14
  • Dwell case 3.jpg
    Dwell case 3.jpg
    50.6 KB · Views: 13
  • Dwell case 4.jpg
    Dwell case 4.jpg
    54.3 KB · Views: 10
  • Dwell case 5.jpg
    Dwell case 5.jpg
    49.9 KB · Views: 9
  • Dwell case 6.jpg
    Dwell case 6.jpg
    51.1 KB · Views: 9
  • Dwell case 7.jpg
    Dwell case 7.jpg
    54.9 KB · Views: 11
Last edited:
Rob Doe said:
But what is the correct dwell for the 'A', guys? I thought I heard Les Andrews say in a YouTube video that 31 degrees was right for a 4 cylinder engine???? A curious mind wants to know the correct number. LOL
Click to expand...

I use Mallory(bullet proof) dists.
One of my units has an alum ID tag riveted
to unit. This tag,unfortunately …. is not
present on all my units (anyone know why ?).
This tag info:
POINT SET AT… 0.021;
DWELL SET AT…0.034.
Your choice what you do with your equipment.

BTW… your friend gave you a GOOD piece of equip !!
I have one , nearly 60 yrs. bot new !!
 
Last edited:
The 715 is a great tool. I had one for years but an undetected leaky battery pretty much ruined it. Take care of yours.
 
You must log in or register to reply here.
Back
Top