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Mac
08-22-2003, 12:05 AM
I'm using a Snap On MT-418 tach and dwell meter to set the points on my BJ7 and when I set the points with a feeler the dwell meter shows about 20 however to reach the magic 35 plus or minus a couple, the points appear to be too far apart. So, one I'm thinking that my dwell meter just isn't working corectly or I'm not hooking it up correctly. The manual does not talk about a positive ground situation just that the red clip goes to the positive side of the battery and the black to ground and the yellow to the distributor side of the coil. Any thoughts? Mac

John Loftus
08-22-2003, 12:33 AM
Hmmm ...

Make sure you have the right type of points for the distributor (Lucas DM6). I've seen two different style points (the P.O. had used the wrong ones ... probably for a DM6A).
When I use the dwell meter (have an old SnapOn model too!) I'm able to get the 35+-3 setting and the correct gap (.014 to .016"). Of course, make sure you have any switches set for 6 cyl. motors and are reading the right scale on the guage.

Cheers,
John

[ 08-21-2003: Message edited by: John Loftus ]</p>

Mac
08-22-2003, 01:04 AM
John, On your dwell meter, do you hookup the red to the positive ground terminal and black to negative? Mac

ThomP
08-22-2003, 09:42 AM
Here's how I connect my dwell meter in a positive ground situation.

The black lead needs to go to the negative battery terminal. The brown wire on the voltage regulator, the big lead from the battery on the solenoid or a brown connection at the fuse box all work. (The supply side (-) of the coil also works if the coil does not use an external resistor). The positive lead needs to go to ground. I use the bolt that holds the coil to the generator. The dwell lead goes to the point side of the coil.

It is not unusual for old automotive test equipment (even Snap-On) to get outta wack. A comparison to a friends unit will provide a reference point for your unit. If the two units agree, you're probably OK. If they don't agree, you both should seek a third opinion or send them into the Mfg. for repair and calibration.

Dave Russell
08-23-2003, 03:06 AM
<blockquote><font size="1" face="Verdana, Arial">quote:</font><hr>Originally posted by Mac:
when I set the points with a feeler the dwell meter shows about 20 however to reach the magic 35 plus or minus a couple, the points appear to be too far apart. Mac<hr></blockquote>

Mac,
Something doesn't add up. Dwell is the amount of time (expressed in degrees of cam rotation) that the points are closed. Increasing the point gap reduces the dwell & vs.
D

Mac
08-23-2003, 03:24 AM
Dave, Good point. That's what I was thinking too and why I was thinking that I was hooking it up wrong for a positive ground car. However I'm hooking it up much like John suggested so maybe there is something wrong with my dwell meter. Guess I better borrow one from someone else and see if there is a difference. Mac