-
Enjoy XS650.com? Consider making a donation to help support the site.
XS650.com receives a small share of sales from some links on this page, but direct donations have a much greater impact on keeping this site going.
Question about new multimeter and dwell
- Thread starter CaseySmithersxs
- Start date
Yes, that looks like it will work. It is digital read out, right? You don't want the old fashion dial type. Got a link to that listing? I've never seen one that has 1 cyl. and 3 cyl. settings before. They may give a more accurate reading on the 650 than the 4 cyl. scale if you could figure out what math formula to use on them (for converting the 2 cyl. value).
CaseySmithersxs
XS650 Junkie
Yep its digital, heres the link. http://m.ebay.com/itm/321211107863?nav=SEARCH&sbk=1
CaseySmithersxs
XS650 Junkie
Any idea?
Newagerocker
XS650 Addict
Use a timing light no math involved.
CaseySmithersxs
XS650 Junkie
I need a dwell meter to set the points........
CaseySmithersxs
XS650 Junkie
Correct me if im wrong? Lol because I set my timing last night, AFTER I gapped my points. 5twins whats your take on this? Haha
Yes, that looks good, it'll work fine. I may even get one. Like I said, I never saw one with lower than 4 cyl. settings. Jeez, I wish someone would make one for a twin. There's enough of us out here, I think there's a market.
You did right Casey - points gap 1st, then timing. Newage is lost somewhere in that "new age", lol.
You did right Casey - points gap 1st, then timing. Newage is lost somewhere in that "new age", lol.
Our points ignitions are basically two single cylinder engines side by side. Shouldn't the 1 cylinder scale work?
On points if you are following the book you can set the points gap with feeler gauges. Once the gap is set you time them with a light bulb or buzzer box or just the volts or ohms scale of any meter. Use the volts with power to the points. Use the ohms with no power to the points.
The dwell meter just gets them a bit more precise.
Leo
On points if you are following the book you can set the points gap with feeler gauges. Once the gap is set you time them with a light bulb or buzzer box or just the volts or ohms scale of any meter. Use the volts with power to the points. Use the ohms with no power to the points.
The dwell meter just gets them a bit more precise.
Leo
The dwell meter is for setting the points gap, that's all, it doesn't do timing. But the thing is, you want the best and most precise points gap to go along with your timing. The points gap effects the timing so it needs to be right. As mentioned, you do the points gap 1st, get it right, then proceed to the timing.
CaseySmithersxs
XS650 Junkie
Lmao he must be. Thanks for the help Twins, going to order that meter tonight. Like Leo said, do you think it would work on the 1 cyl setting?
On the gap, being more precise on the gap is better. It controls the dwell angle or the time in degrees of rotation the points are closed. This is important to properly charging the coil.
Once the gap is set it won't change, so it won't effect the timing. To adjust timing you adjust when the points open. You do this by adjusting the backing plate to cam relationship. You don't change the points gap.
Leo
Once the gap is set it won't change, so it won't effect the timing. To adjust timing you adjust when the points open. You do this by adjusting the backing plate to cam relationship. You don't change the points gap.
Leo
Do you know how hard it is to find a match book cover these days?
CaseySmithersxs
XS650 Junkie
Yea I know how to do all of that, and yea the gap does change over time with cam wear ext.
I agree with Leo, in that you can measure dwell for 1 set of points (left or right) as if it was a single cylinder engine.
With the meter selected to 1 cylinder, you want to see a reading of 93 degrees (Yamaha spec) on the meter.
If you selected the 4 cylinder position on the meter, you should read 23.25 degrees.
With a 4 cylinder engine, 90 degrees is the maximum angle available, and 93/360 is the desired dwell from Yamaha's spec.
93/360 X 90 = 23.25 degrees.
If you selected 6 cylinder:
60 degrees is the maximum angle available,
93/360 X 60 = 15.5 degrees.
With the meter selected to 1 cylinder, you want to see a reading of 93 degrees (Yamaha spec) on the meter.
If you selected the 4 cylinder position on the meter, you should read 23.25 degrees.
With a 4 cylinder engine, 90 degrees is the maximum angle available, and 93/360 is the desired dwell from Yamaha's spec.
93/360 X 90 = 23.25 degrees.
If you selected 6 cylinder:
60 degrees is the maximum angle available,
93/360 X 60 = 15.5 degrees.
Newagerocker
XS650 Addict
I tried to figure what dwell angle should be on my ancient analog dwell tach and equate it to the 8 or 6 cyl scale arcs. Feeler guage and a light have served me well. If you need to be real precise I have quite a few matchbooks here as I gave up smoking 40 years ago.
Have you ever actually measured the dwell angle, of your XS650, using the 6 or 8 cyl scale?
On most analog meters, the scale starts at 20°, not low enough to read the converted 6 and 8 cyl. values (1/6 and 1/8 of the actual 2 cyl. value). That's why I use a digital unit. When doing this, you should use the lowest scale you have available for the most accuracy. I may get one of these with the one cyl. scale. That would be great if it could be used and read the full 93°. Well actually 88°-98° (93°Â±5°).
Yes, the XS650 uses a very short dwell angle as compared to a 6 cylinder or 8 cylinder engine. I believe the 6 cyl and 8 cyl, typically had the points closed for 60% of the time available, as compared to the XS650 that only has points closed for 25% of the time available.
The more cylinders an engine has, the less time available to charge up the magnetic flux (especially at high rpm's). 1 and 2 cylinder engines can use a shorter dwell angle, because they have more time for the dwell to happen. Pamcopete was able to reduce the Pamco dwell from 93 degrees to 60 degrees, which reduces current needed, but still gives a healthy spark.
The converted dwell would be:
6 cyl scale = 15.5 degrees
8 cyl scale = 11.6 degrees
Last edited:
Newagerocker
XS650 Addict
I actually came up with the dwell angles as stated by Retired Gentleman albeit the scale only goes down to 15 degrees for 8 cylinder and 20 degrees for 6 cylinder as stated by 5Twins. So I didn't see any point to using it. I have always been happy with my '77s running just using feeler gauge. I did happen to notice my MAC tools multimeter has 4 cylinder dwell angle selection. I'll try it sometime.
