Points Dwell & Timing Settings

I tried setting the dwell on my 650 with an Actron dwell meter which only has 8 cyl & 6 cyl scales. My manual states 180° as the dwell spec, which after dividing by 8, is 22.5°. I got it to 23° which should be close enough. The problem is that I couldn't get the timing right. The 1-4 points had to be set all the way to one side and the 2-3 points were set all the way to the other side, and I still couldn't quite get the 2-3 side set properly. So I'm wondering if 22.5° is correct, or if I need to divide the spec by 4 and set them to 45°. BTW, prior to adjusting, both sides were at 28-29°. Does the dwell reading increase or decrease over time with wear? Am I using the correct specs?

Thanks.

My book says to divide by the number of cylinders your meter is set to, so apparently you have it right.

I wouldn't sand the spring. It won't help anything and you might promote stress cracks.

Dwell is the amount of time (ok, degrees of crank rotation) that the points are closed, so dwell will increase as the rubbing block wears away.

You can check if the dwell spec is right by using a feeler gauge. If the gap is close to spec, you're using the right dwell meter reading. If the gap is way off, your meter reading is too.

steell wrote:

Dwell is the amount of time (ok, degrees of crank rotation) that the points are closed, so dwell will increase as the rubbing block wears away.

That's what I was afraid of. I took another look at the manual for the meter, and it says, for a 4 cyl, to multiply the 8 cyl scale by 2. Since the KZ behaves like two 2 cyl engines, wouldn't that mean I need to multiply by 4, not 8? If so, that means I need to adjust the dwell to 45° on my meter's 8 cyl scale, but that doesn't explain why they were set to 29° before.

Sounds like I may need a new set of points. Anyone have any experience with those available at Z1? They have two different brands, Sudco and K&L. Which are better?

You are measuring the CRANKSHAFT dwell angle which is 1/2 the CAMSHAFT dwell angle. so you need to multiply by two more

-Duck

Duck wrote:

You are measuring the CRANKSHAFT dwell angle which is 1/2 the CAMSHAFT dwell angle. so you need to multiply by two more

-Duck

So is it different for cars vs bikes? Just thought of a way to check this. 180° of camshaft rotation is 360° of crank rotation which I can check with the ignition cover off. I can just connect a multimeter across the points, rotate the engine and see when the points close and when they open.

Most dwell meters are for cars. Cars measure dwell in the distributor which turns the same as the camshaft. Your KZ measures dwell at the crankshaft which turns twice as fast.

So as Duck said, and as you already suspect, you need to multiply by two more.

For example, my Sunpro only has an 8-cyl scale for cars and it measures cam-angle. (Same as your Actron.)

I have to double it for a 4cyl car.

On the KZ, I double it again because you only measure one set of points at a time, which makes it appear as a 2cyl engine.

Then I double it again to take the cam-angle reading and convert it into crank-angle.

In my case, I have to multiply the reading by a total of 8.

Post edited by: loudhvx, at: 2006/09/12 12:58

bemoore wrote:

steell wrote:

Dwell is the amount of time (ok, degrees of crank rotation) that the points are closed, so dwell will increase as the rubbing block wears away.

That's what I was afraid of. I took another look at the manual for the meter, and it says, for a 4 cyl, to multiply the 8 cyl scale by 2. Since the KZ behaves like two 2 cyl engines, wouldn't that mean I need to multiply by 4, not 8? If so, that means I need to adjust the dwell to 45° on my meter's 8 cyl scale, but that doesn't explain why they were set to 29° before.

On your meter it should be the 8-cyl scale times 8 like on my Sunpro. You should set it to 22.5 degrees.

More importantly, how do you get that little degree symbol to show up on posts?

Post edited by: loudhvx, at: 2006/09/12 12:54

loudhvx wrote:

bemoore wrote:

steell wrote:

Dwell is the amount of time (ok, degrees of crank rotation) that the points are closed, so dwell will increase as the rubbing block wears away.

That's what I was afraid of. I took another look at the manual for the meter, and it says, for a 4 cyl, to multiply the 8 cyl scale by 2. Since the KZ behaves like two 2 cyl engines, wouldn't that mean I need to multiply by 4, not 8? If so, that means I need to adjust the dwell to 45° on my meter's 8 cyl scale, but that doesn't explain why they were set to 29° before.

On your meter it should be the 8-cyl scale times 8 like on my Sunpro. You should set it to 22.5 degrees.

That's what I set it to but it doesn't make sense that the multiplier is 8 instead of 4.

loudhvx wrote:

More importantly, how do you get that little degree symbol to show up on posts?<br><br>Post edited by: loudhvx, at: 2006/09/12 12:54

Hold down the Alt key while entering 0176. Alt 0177 is "±" which also comes in handy on occassion.

OK. The verdict is in. I set the dwell to 22.5°, shut down the engine, and connected the dwell meter and rotated the engine slowly to find the open/close positions. The result: 22.5° on the 8 cyl scale equals 180° of crankshaft duration on the KZ. The only way this can be right is if the meter reads in camshaft degrees. My Clymer manual specifies dwell in crankshaft degrees so I thought that the meter would read in those units. Also, this reading (22.5°) corresponds to a 50% duty cycle. I.e. the points are closed 50% of the time. Which means that 45° on the meter corresponds to 100% duty cycle, which, of course, is not possible. I couldn't have achieved 45° if I had to.

OK. That's settled. Anyone have an answer on my question regarding new points from Z1; Sudco vs K&L? These points were a pain to adjust. I think I need a new set.

New question: Should there be any arc'ing across the points? I thought it was the job of the condensor to eliminate that, so the arc'ing I'm seeing makes me think my condensors are bad.

Post edited by: bemoore, at: 2006/09/12 20:38

bemoore wrote:

New question: Should there be any arc'ing across the points? I thought it was the job of the condensor to eliminate that, so the arc'ing I'm seeing makes me think my condensors are bad.<br><br>Post edited by: bemoore, at: 2006/09/12 20:38

The condenser doesn't entirely eliminate the arcing. If it's arcing a lot, then maybe they're bad.

If you are interested in tinkering, I have plans for an electronic ignition which uses the points as a trigger. You'll still need new points, but they will last indefinitely. The ignitors cost about $15 each at parts stores.
www.geocities.com/loudgpz/GPZheiModForPoints.html

The alt-0176 doesn't seem to work for me... probably some setting I need to fiddle with.