Wanted, Bad Venture Coils

[V7Goose]

Kent, That is good news!

 

Now keep in mind that I had removed that

cap off that wire a couple of times and screwed

it back on.. not sure if that helps you your not.

 

Is the problem deep inside the cap OR were it screws into

the cap?

 

Also, is it possible for us to maybe cut off a 1/4 Inch

of the wire on the so called bad coils?

 

Will you be able to cross section that cap?

 

Anyways, thanks for what your doing!

 

Jeff

Since the wires are copper core, screwing the cap on and off does not hurt anything. And there is no value in trimming the end. Those are both reasons why I said we are lucky to have copper core wires instead of carbon core.

 

Now for those that may not understand the difference in spark plug wires and caps, let me explain a little. Carbon core wires were developed to reduce radio interference from ignition spark. The carbon core works like a resistor that dampens the transmission capability of the power pulse. The problem with carbon core is that it is brittle and breaks down easily. This is especially true at the end where it is common for the cap to make contact by turning a screw down the center of the wire.

 

Another way that is used to suppress spark noise is with a resistor inside the spark plug cap or the spark plug itself. The cap on these coils is a resistor cap, and it can be taken apart. And that is where I found the problem. Below the resistor is a long heavy spring, and one end gets corroded (the end way down deep in the cap). On yours, the corrosion looked fairly innocuous, just a dull grayness on the last 1/4", but it was significantly affecting the conduction of the spark through the cap. This was shown on the scope by the coil having to push a 50% higher spark before the plug fired.

 

Interestingly, I dismantled the two rear caps on my own RSV (and those coils are working perfectly), and I found much greater corrosion in mine than I did in yours! Pictures will be included in my detailed writeup later. The corrosion on the springs in my caps was more thick and crusty instead of the thin oxidized layer on yours. Until I cut one of these caps open, I can't speculate on what is causing it or what we might do to prevent it, but it is hard to imagine that it is caused by moisture. If we can find a way to properly clean way up in that little hole, then clean the end of the spring, I think dabbing the spring in a bit of dielectric grease before it is put back together might be a permanent fix.

 

Actually, now that I think about it, that may be the whole answer - maybe there WAS factory dielectric grease in mine, but none in your coil? I remember back in the day when just about all cars and trucks used normal distributor caps, and some called for dabbing a bit of dielectric grease on the new rotor and cap contacts. I always found a nasty, dry crusty mess on those parts when I took an old cap off, very similar to what I found on the ends of the springs in my caps! Gonna have to think about this more, and inspect more bad coils to see if that spring looks the same on all the bad ones. I'd also like to take a peek inside a brand new cap!

Goose

[juggler]

...I think dabbing the spring in a bit of dielectric grease before it is put back together might be a permanent fix.

 

Actually, now that I think about it, that may be the whole answer - maybe there WAS factory dielectric grease in mine, but none in your coil? I remember back in the day when just about all cars and trucks used normal distributor caps, and some called for dabbing a bit of dielectric grease on the new rotor and cap contacts. I always found a nasty, dry crusty mess on those parts when I took an old cap off, very similar to what I found on the ends of the springs in my caps! Gonna have to think about this more, and inspect more bad coils to see if that spring looks the same on all the bad ones. I'd also like to take a peek inside a brand new cap!

Goose

 

I was thinking the same thing as soon as you mention corrosion. Having grown up in my Dad's gas station garage I did lots of tune ups and dielectric grease was the order of the day on the older cars. I never did try to clean the old stuff up since we just tossed out the plugs, caps and wires during most tune ups.

[Cougar]

Kent, Also remember my 2000 only had 11,700 on it

when I removed the coil I sent you.... your bike

has WAY over that I am sure. (more time, heat, weather etc.)

just a thought. I still am trying to get out to the garage today

and will let you know by tonight or tomorrow what I might

find on the two front coils.

 

Another thing that came to mind is that I always run a number (7)

plug and my bike likes it. (hotter plug) not even sure if that has

any effect on the coils or not. just wanted to add that as well.

 

Thanks so much for your hard and dedicated work on this matter,

 

It would be interesting to have that cap of mine cross sectioned!

 

Jeff

Edited August 9, 2009 by Cougar

[V7Goose]

I have now received one coil from Cougar and two from wkboard. In addition, I have tested my own coils (2005 with 70,000 miles), and dismantled/inspected the caps on a 2004 and a low mileage 2008. I hope to get more coils to continue testing, but I can begin to draw some conclusions from what I have seen thus far.

 

As noted in a previous post, Cougar's coil was put through a full battery of tests, including an automotive oscilloscope and a heat test. The coil itself passed all tests, but the cap had high resistance. When I dismantled the cap, I found a layer of oxidation on the end of the internal spring that goes deep inside the cap (near the end where the wire attaches). After I cleaned the end of the spring and reassembled the cap, all was well.

 

Of the two coils wkboard sent me, both coils check out fine on the bench, but one cap (from the right rear) was absolutely bad. I have not yet hooked these coils up to my bike and the scope, but I feel fairly certain they will pass all tests that way. When I dismantled the caps, both had heavy corrosion on one end of the spring. After cleaning and reassembly, the good cap, which had been within spec on resistance, was improved with lower resistance. But the bad one was completely shot! Turns out the resistor was bad, and the more I played with it, the worse it got.

 

All of the caps on my bike had heavy corrosion on one end of the springs, but still had good resistance too. I found the same thing on all four caps on the 2004 I worked on at Vogel last week. On the one cap I dismantled on a low-mileage 2008, the spring was NOT corroded at all, nor was there any sign that there had ever been any dielectric grease on it.

 

Conclusions thus far:

I suspect that 90% or more of all the bad coils we hear about are REALLY bad caps, and the coils are fine.

 

The corrosion I find on the springs is always on the end near the wire, but I cannot find any cause for it - when I look inside the cap with a bright light, it is always perfectly clean. The cap is completely sealed and also has a rubber boot around the wire and top, so there is no way any moisture can leak in that way. In most cases, cleaning the end of the spring on a wire wheel, or simply rubbing it on concrete, solves the connection problem and puts the cap back in spec for resistance.

 

There is a possibility that the corrosion on the spring is actually a red herring and is not affecting the connection in any way. The problem might actually be the connection on the resistors, and just unscrewing the internal parts and then reassembling the caps may be what is cleaning up those connections. I will need to work on several more coils before I can test that possibility. From my experience with the one bad resistor, it seems that they are a little delicate and cannot be cleaned the same way the spring can.

 

More to come if I get more coils to test!

Goose

[LilBeaver]

Goose:

 

Your hard work on this is definitely appreciated. As far as I know mine are working fine, but I am tempted to pull mine apart out of curiosity (not this weeked because I am still going to try to make it out to wildhair's tomorrow)...

 

Keep up the good work! We all appreciate it!

[Cougar]

Great Job VGoose...

What and were is the bad resistor? (picture?)

 

You say (spring?) what and were is that? (picture) .

 

This is something we can do or prevent as a yearly maintenance thing?

 

OR do these caps need to be replaced?

 

Thanks for what your doing!

Jeff