Bad Coil

[oldyam80sg]

I checked my ignition coils as per the thread. I switched wires (orange and grey) and the coil i suspected was bad had a weak spark.How come the bike starts with the #2 and #3 cylinders but when i hook up the coil for #1 and #4 the bike doesnt want to crank? Is the coil internally bad or is it just the spark plug wires?

[midnight1980]

Re: Bad Coil

Originally posted by oldyam80sg
i hook up the coil for #1 and #4 the bike doesnt want to crank?

i never heard of this i changed my coils and wiring harness and my bike will not crank over at all ? know one said anything about this here
i hope its not the same probem as yours..

[oldyam80sg]

I put a set of Accel wires into the old coils as per the thread.Right now as we speak, the rtv sealant is curing.Will let you know the results.

[TopCatGr58]

Hey OldYam,

You'll need to be a bit more specific on what you have switched, etc., it's difficult to follow XSactly what you have or are trying to do, with 2 coils and 4 plug wires???

You mention swapping the Grey/Orange wires....and you found a suspect coil had a weak spark. Then you state about hooking up the coil for 1-4 and it runs...are you now talking about still having swapped the gray/orange wires, or are you talking about having gone back to the OEM config, and the bike will run when the 1-4 coil is connected, but won't run on just the 2-3 coil, or won't run with the 2-3 coil in conjunction with the 1-4 coil????

Have you pulled the plug caps off and inspected the wire on the suspect coil? Have you checked with an Ohmmeter both the suspect coil thru the plug wires WITHOUT the caps, as well as measuring the plug caps for resistance??? The caps can go bad, but so can the coils, or you can just have a lot of corrosion inside the cap where the wire connects!!

More info, and please be more specific....remember, we're not there looking over your shoulder, so you have to draw us a very good mental picture!
T.C.

[oldyam80sg]

Top Cat- per the thread, i switched the orange and grey wire that connects the one set of coils.#1 and #4 coil- the spark is barely there.I switched the wires back to where they belong,and the #2 and #3 fire indicating that the coil is good.The spark is nice and white in color.I replaced the spark plug wires in the bad coil and will see if that does anything.I will test them with an ohmmeter tomorrow.

[oldyam80sg]

Top Cat also the wires that i replaced in the suspected bad coil have the caps built into the wire.The old spark plug wire looked like it was burnt.

[randy]

TCI solder fix may be in order. Take a look at my profile and go to my www. for instructions

[TopCatGr58]

Hey OldYam,

At the risk of repeating myself, although many here(or at least PROM ) will say I do like to hear/see myself talk!

Before you went thru all of that trouble of replacing the wires on that ?burnt? coil, did you check it with an Ohmmeter, both Primary leads and high tension side? IF it didn't measure out to within spec, the wires won't do much good!?

Also, you switched the trigger wires, so that both coils were tested with the same trigger set, got poor spark from the 2-3 coil, but good spark from the 1-4 coil, both using the same trigger wire. Then the 2-3 coil is BAD, not good. I think I remember recently reading and reviewing the Tech Tip that was written many years ago, and found that it wasn't quite correct in it's conclusions on it's diagnostic steps!

IF you had gotten good spark from both coils on the same trigger wire(ie. gray), but poor spark from the "other" trigger wire( orange), then the coils would be good, but either the TCI or Pickup coils are faulty. Hope this helps and clears things up.
T.C.

[oldyam80sg]

Randy do you live in Stroudsburg PA ? I could meet you and give you my TCI unit and pay for you to look at it.I checked out the TCI unit as per the block of instruction and tested it with an ohmmeter set on volts and everything checked out as per the specs.Years ago i had aproblem with the coils and replaced them-(thats when they were available !)I think that the problem lies within the coil /wires.I can only try and see if the new wire in coil fix as per the thread does the trick! But Randy think about my proposal please!

[TopCatGr58]

Randy's good people and does great work on these TCI's! He's also had folks MAIL them to him as well!

IF you do end up replacing the coils, there's a thread, and soon to be tech tip added about the inexpensive and quality high output ones from MikesXS.com . They work very well, and much cheaper than trying to get OEM from Yamaha!
Good Luck.
T.C.

[randy]

oldyam80sg;

I'm only in Stroudsburg on weekends, you're welcome to come over and we can swap your TCI onto my bike for a difinitive test?

[oldyam80sg]

TopCat- I checked to make sure that the wires in the advancer unit are good.I took the 4wire connector in the ignition unit,unplugged it and the meter said 738 ohms (checking pick up wires thread)According to the thread it is supposed to read 600 ohms.So it is a littlle high.Tried to check if i was getting spark in #1 and #4 wires to spark plug- no good, bike will only backfire and not run.I had to remove battery because it would not crank and the battery read 11.38 volts not connected.Only #2 and #3 cylinders will fire.Tried to check plug caps. Will need to see how to check these.

[oldyam80sg]

Randy, When i get a chance i will contact you about meeting in Stroudsburg on the weekend and i will bring up my TCI unit.Maybe we can do breakfast at Perkins!Thanks

[oldyam80sg]

another problem

TopCat as i previously mentioned i removed the battery from the bike because i went to hit the starter and the bike would not start.I push started it 2 times to get it going.I had the battery sitting on a charger for 3 1/2 hours and still the lights would not change.No bubbles or anything in the cells.I suspect one cell is dead as it did look pretty low. Battery is no good even though i tested it with a voltmeter and it read 12.26 volts.New battery is $45.00 at wal- mart.Took old battery off of charger and volts started to drop.Could the battery have an effect on spark?

[HobbyMan]

Just because a battery shows 12v has no bearing on if it is good or not. Internal resistance well prevent it from putting out its rated cranking amps. I too am confused about how you swiched the coils. I probable will never understand exactly what is going on. As long as you switch the wires on the coils and those on the harness. Just measure the resistance on the primary and secondary coils like said. Rember the caps have resistance too.