Checking cap-to-cap resitiance. You can laugh at me.

[Redman]

GOing to the Brown couty rally thursday (290 miles for me), and I was about 3/4th the way there and bike started running bad. At higher speed was a bit of hesitation and under acceleration was worse, power would not completly die (like happens when fuel starved) but was like the power would go to half and then back real quick and real abrupt, chattering some times.
I concidered turning around and head north back toward home so when if completly quit I would maybe be a little closer to home. But it wasnt getting any worse, so I kept going south.
Made it to Bedford, but didnt say anything about the problem. I dont really know why I didnt say much. THere are all these guys there that are quite knolodgeable and helpfull friendly. But I didnt want to have to discuss it. I was pondering my options.

Friday morning I did tell Norm and some others that I would not be leading a group.
I carry some tools and multimeter. I asked to borrow a spark plug wrence from Steve.

Waited untill most folks left for the day. THen I took off the fairing lowers and removed the seat and the tank.

Greg GBW was there and hepled me hold the meter leads and we measured resitance from cap 1 to cap 4, and the meter reading was infinite most of the time but might also jump all over and going to zero and going to infinite, so Hey, I thought I was on the right track of broadly locating the problem, since I was not getting the reading I was expecting. But geepers, could it really be the first thing I suspected and checked? CAn I reall y be that good, that I properly dignosed the problem just from the basic symptioms....?
So to verify things, and to troubleshoot things to furter narrow down the problem further, I took off the caps, and each cap meaured right at about 5k, good, and from wire to wire was just under 20k, good. So that both seemed good but was not consitent with my reading from cap to cap. So I looked and pondered some more and noticed that I had stuck the meter probe well up into the wire, but right at the end of the wire was only like one thin strand of wire and it looked all discolored. So I trimed back each wire about 1/4 or 3/8 inch to where there was more strands and looked better. Put on the caps, and measured again expecting to see better reading.... but nope, meter jumping all over, showing numbers then 0 and then infinite then numbers bouncing around and so on. So I pulled off the caps again, to inspect things, and put back on, and measured again, nope.... still suspect readings on meter.
By this time Dale Dogma was around, lending a hand with meter leads. THe meter did go blank on one occassion, so we though maybe batrtery going weak.
I also though that maybe the meter did okay reading the resistance of the resistor in the cap, and did okay reading the resistance of the coil of wire, but the coil of wire is really an inductor that can build up a magnetic field. And maybe for some reason the meter has a problem when the caps are on because then the circuit is then resistor and inductor... but that didt really make scence either. Dale and I are discussing the physics of this phenomia.... some others looked at us like we were some weirdos or something.

Was not till this morning, 5 days later, it occured to me: I had the meter on the 20K scale (so up to 19.99K) and the caps plus the wires plus the coil is about 30k ... doah. That is what was going on with my meter, I was overranging the meter. TO measure something that is suppose to be about 30K the 20k scale is not going to do it. Next scale would be the 200K (up to 199.9k) .... doah....

[Redman]

My selfie. Tanks off, seast off, lowers off. Meter out to ohm check the ignition secondary.
Exclaiming that "Ah, Here, Am on the right track. This is suspect."



To use Bob Baatfam post/pics:

Friday Morning....
.
As Redman (Dave) mentioned, he had a bit of an electron issue, but he resolved it that morning, with a little help from GBW (Greg).



....

[Nessism]

Did trimming back the high tension leads solve the running problem?

[Redman]

Did trimming back the high tension leads solve the running problem?

Yes... Maybe.... Dont really know.
I also found a couple suspect sparkplugs with a molten ash build up on the ground electrode. It didnt close up the gap, but plugs were fairly old. So also installed 4 new sparkplugs.

The main point of my story is about me having strange reading on the meter, and me trying to analyise the physics of how the meter operates and the electrical propertys of the ignition secondary .... and the strange readings on the meter was due to not having the meter on appropiate ohm scale. Duhhhh.

My story purposly avoided the defered basic maintenance aspect story.

[Hinermad]

The main point of my story is about me having strange reading on the meter, and me trying to analyise the physics of how the meter operates and the electrical propertys of the ignition secondary .... and the strange readings on the meter was due to not having the meter on appropiate ohm scale. Duhhhh.

You're not the first person to overlook his meter's settings. Several times I've popped a fuse in a meter when I tried to measure battery voltage on an amps input. My biggest oops was trying to measure the voltage of a wall outlet with the meter set to resistance. I let the smoke out of that one.

[Wingsconsin]

The use of a meter is primarily wizardry for me-Alchemy and black magic is all I need to keep the smoke inside the wires.
And if the smoke goes out -- I buy new wires
After that it may as well be a course in Chinese arithmetic for it is well beyond my scope of experience.

I feel your mistake was in the NOT seeking advice adn help from that group of incredibly knowledgeable GS folks -
If you had mentioned it I would suspect a chorus of people checking the bike over and finding a diagnosis within hours if not minutes.

If I had been there I would have surely stood around and wondered out loud if I could help - and of course my limited experience would not give you recourse to accept - at which point I would feel vindicated for my willingness yet sorrowful for my ineptitude.

[Dogma]

Hmmm..... Wrong range on the meter, or induced transients from the coil... You might have had some electron/positron annihilation going on too. That might cause some funny readings.

[Redman]

Oh, No, electron/positron annihiation.
I thought it was my mental malfunction.

On the 20k scale it would read the wire-to-wire of about 19.something K ohms, good and solid, and that is portion off all this that has the inductance.
And would read each cap at 4.9something or 5.0something.
But cap-wire-coil-wire-cap (about 30K) reading would bounce all over, maybe go to zero and infinite and then bounce around some more. So, I now know that is how that meter indicated overrange on the ohm scale anway.

I suppose a good test would be to try it again, on the next scale (200.0 K).

Dont use this meter much, is the one in my sidebag. My other meters (Flukes) that I used more are autoranging.

[Redman]

Did find the problem of the suspect wires in a couple minutes after removing the seat-tank-lowers.
Toatal time, including trip to parts store (Thanks again Bob Baatfam) and short test ride was about 2 1/2 hours.
I know I was out on the road for an afternoon ride at about 1230 and I started working on it about 915.

[dorkburger]

...... auto ranging meters are nice. Probably overkill and expensive for hobbyist though, and not particularly small for packing on a cycle.

I've also blown a number of fuses on my older meter due to having leads in the wrong port. The small fuse in it blows at 44/100 of an amp- in other words easily, and naturally its a specialty fuse.

The local supply house had a meter that they would show customers- its owner wrapped the blown fuse in it with tinfoil in a pinch and smoked the entire meter.

[BigD_83]

How about I laugh with you? I think we've all done something similar. Usually the second set of eyes picks up the mistake right away, but often it is late in the day and we're caffeine deprived.

[Redman]

.... .... .... ... , but often it is late in the day and we're caffeine deprived.

My problem, other than being nervious, was that the meter(s) I am accustome to using at work and in my garage are auto-ranging. When I was using the meter I carry in sidebag there in the motel parking lot, I set it on the ohm scale, the 20k range, and didnt stop to think about it again. It checked the caps okay at about 5 K each and the wire-coil-wire okay at just less than 20k, 19.9something, but was giving me goffey readings for the cap-wire-coil-wire-cap ..... DOAH!

When I first checked the cap-wire-coil-wire-cap it showed a good solid OPEN, unless I wiggled the wire some. So i knew was some problem there. Trimmed the wires and then would give the goffey readings all the time, so I know I had made some improvment for the better. But was still puzzled by the goffy readings for sometime.

Got into a detailed discussion about the physics of checking a resistiive-inductive circuit with an ohm meter, a very theroretical discussion, when overlooking the practical matter of what range I had selected on the meter DOAH Sccceeeesssccchhhhhh.
Somebody should have told the two engineers to go away, and let an electricain or a technician or a mechanic work on it. har har har

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