Points and spark questions... on a VLH

[Jim]

I am trying to get a '36VLH running again. It has sat for maybe close to 5 years without running it. After a few "fixes", I tried to start it and found that it had no spark. I checked the points and found they didn't spark. Then I tested with a test light, it was "lit" with them open AND closed so I figured they only were very dirty and just weren't making contact. I took them off and cleaned them with some emery cloth. Now, I tested them and I had a 'good' contact with a multi-meter. However, after I put them on the bike, I cannot get a spark to jump or snap when I flick them open. (know what I mean?) IF I see any type of spark it is so minimal and next to nothing. I also have my plugs out and laying on the heads so when I kick it, I can try and see if I have any spark jumping on the plug... which I DO NOT (yes, I know it is because I am not getting any point spark) plus, it is easier to kick over without plugs for "testing" reasons.

So... are they just bad points? Condenser? OR is it possible for the coil to go bad from sitting so long? Is there anyway to test the coil and/or condenser?

The battery is OK as I just took it out of another VL which DOES run.

Thanks!

[Jim]

All right... 2 hours later, I decided to swap out the points and condenser from the non-running VLH bike and I put them in the running VL. After I put the points in the VL, it started right up. OK... points and condenser from VLH are BOTH GOOD.

So... I suppose it is the coil. Anyway to check or test a coil?

[Jim]

Upon some further testing and checking. I found out that when I turn the key ON and the points are closed, the amp meter goes FULL Discharge. It should only be a couple of amps drop. So, now I am wondering if there is a 'short' somewhere on the HOT side. Sure, it could be shorting out inside the coil too. Will check it out tomorrow.

[knuckleheadtim]

You may have both the coil pos. and neg. primary wires connected to the same terminal on the coil, or as you said, a bad coil.

[Jim]

You may have both the coil pos. and neg. primary wires connected to the same terminal on the coil, or as you said, a bad coil.

I haven't touched any wiring.... and it "used" to run. I am going to try and test the coil tomorrow. Will post back then with any result I find.

[Jim]

Looks like the coil it BAD. I only got a .6 Ohm reading on it. Doing some searches, I found that the aftermarket coils were built backwards? Then that made me check mine and sure enough, I had the Points wire connected to the PLUS (+) side of the coil.

Is there only one manufacturer of repro coils?

[knuckleheadtim]

I disagree with all of the posts saying that coil polarity matters on a dual-fire coil. One cylinder will always fire reverse polarity, and switching the primary wires only changes which cylinder fires reverse. The primary and secondary windings are isolated from ground and from each other, unlike a single fire coil.

I measure about 1 ohm across the primary terminals on both stock and repop coils. On the secondary windings, I get 30k across the stock, and 200k across the repop, Both primary and secondary should measure infinite to each other and ground.

[Jim]

I had seen a diagram with the one plug firing always firing reverse.

As for ohms, I found on my 'good' coil checking between the terminals I get 1.2 ohms. The bad coil, I get .6 ohms (as said above). So, when I DO get my new coil, I will just put the Switch wire (+) onto the (+) side of the coil to be on the safe side. I suppose that I should have said that the coil is about 20 years old but really hasn't had much "running time" on it. I don't ride them 1000's of miles. Maybe a few hundred miles a year. I have Not checked them to "Ground".

[Jim]

Just an update... The coil was bad. I replaced it and now the VLH runs again. The new coil ohm reading across the terminals is 1.5

[bselph]

Great. From whom did you end up getting the coil? Maybe I need a spare for my long rides.

[Jim]

Hey Bob, I got it from "45Restoration: http://45restoration.com/.

Here is a link to the coil I bought: http://45restoration.com/Products/Co...02-30B-6V.aspx