Ok here is an interesting Electrical question

[snyper316]

Alright I have a question for any of you who has ever been Bit while working on spark plugs wires while the key was in the on position... but noone hit the starter button.

 

The question here is when Marie was up and running and I had to trim Back wire to get rid of some corrosion I was listening to my radio and had flipped the key too far anyways while i was using wire cutters to cut thru the spark plug wire i felt a little tingle.. So that gave me an idea to use a test light to check the rest of the wires i found another dead wire that way out of 4 i had 2 dead ones... all i did was simply used my test light put it in the cap and hooked other side to ground and had a dim light in the tester after i trimmed all the wires i then hit the starter to check them all and the light would go from dim to brighter when i would crank the bike. well it no longer does this and i can only check for a spark by sticking screwdriver in the cap and ground against body and i see weak sparks and one coil aint getting power at all which has basically left me to believe the TCI unit is bad.. However my question is just about that initial thing i discovered with low voltage going thru plug wires. so i have seen talk about Initial charge here and there and that pick up coils send the signal to tci to send fire charge to cylinders, so basically if i havent confused any of you at this time cause i am just curious if that is something i was supposed to see happen? the low voltage coming thru the wires when key was just in On Positions anyways thanks for all the help this far... by the way Marie was built in 83':think:

[Flyinfool]

As far as your ignition circuit is concerned having a bulb filament is like having a direct short across the coil. No electronics appreciates that. The reason that the bulb does not die instantly is because the spark circuit is not capable of producing enough amps to make the bulb act like a fuse. That is why they make spark testers so that the power is still jumping an air gap for proper resistance.

 

As for what you are seeing with your test. I wonder if it is indicating bad coils. You have +12V to both the primary and secondary sides of the coil at all times the ignition is turned on. The TCI switches the ground on and off to the primary side control the spark. So with the key on you should see voltage at the high tension leads at the spark plug. there is a small resistor in the spark plug cap, it is very common for this to corrode and cause a poor connection. You can take the plug cap apart and clean the parts. DO NOT remove any material from the resistor element or you will kill it.

[snyper316]

As far as your ignition circuit is concerned having a bulb filament is like having a direct short across the coil. No electronics appreciates that. The reason that the bulb does not die instantly is because the spark circuit is not capable of producing enough amps to make the bulb act like a fuse. That is why they make spark testers so that the power is still jumping an air gap for proper resistance.

 

As for what you are seeing with your test. I wonder if it is indicating bad coils. You have +12V to both the primary and secondary sides of the coil at all times the ignition is turned on. The TCI switches the ground on and off to the primary side control the spark. So with the key on you should see voltage at the high tension leads at the spark plug. there is a small resistor in the spark plug cap, it is very common for this to corrode and cause a poor connection. You can take the plug cap apart and clean the parts. DO NOT remove any material from the resistor element or you will kill it.

 

Yeh I have taken these caps apart and cleaned them up and i knew not to mess with resister basically my question was if there was supposed to be very low voltage in the high tension wires with the key on i would say there was posibley 2 volts give or take. Ive already done all the other testing by reversing coils etc to see if there was spark and i know all 4 coil packs are good.. and all 4 high tensions are good just replaced spark plugs so she does try to turn over but the only thing i dont have anymore is the low voltage going to my high tension wires. I just never would have done that if i hadn't got bit while the bike was just in the on position. I just dont have papers with a certification and all the bikes i have ever owned were on the points system and the old way of testing spark well im too hold to hear hold this medal thing while i pull the chord lol... so I may be confused of what your saying because there again i see primary and secondary and if i have understood everything correctly I think what your telling me yes I should see low voltage in the high tension wire.... and the secondary is from the pick up coils and the one that actually sends the spark... correct me if im wrong.. I have problem when i try to explain things and sometimes sound a bit well cocky not try to but i am pretty much learning with the bikes because i have always had point systems and this electronic stuff on the bike is crazy i never did like it in the cars... but have learned to live with and learned to work on them and it seems it has made them easier to work on for the most part......

Edited July 25, 2016 by snyper316

[snyper316]

O and by the way i used to work at Coin Ops and we put together boards and test them and sometimes they would have bad resisters so i took good resistor home and bad resister and took them apart... the wire went from what i remember all the way thru that stoney stuff and after tearing those resisters up i never did figure out what was wrong with the bad resister

Edited July 25, 2016 by snyper316

[snyper316]

Got a question what does yamaha do with there stuff when there done building a specific bike because if they have discontinued the tci boards would mean that they would have the testers to test them.....

[Flyinfool]

First we have to be on the same page with terminology.

The pick up coil is located down by the Stator and it is what tells the TCI the location of the crankshaft and the RPM of the engine.

The TCI uses the information from the pick up coil to decide when each plug needs to fire. Since the coils are all wired hot the TCI controls this by switching the ground on and off. At the moment that the ground is taken away by the TCI is the moment that the spark plug fires. Each ignition coil has 2 windings of wire, the primary and secondary. The primary is the one that the TCI is controlling the power to. When the power is flowing through the primary it is an electromagnet and builds up a strong magnetic field. As soon as the power is turned off BY the TCI that magnetic field collapses, it is the magnetic field that is collapsing around the secondary winding that actually creates the spark voltage for the plug.

 

With all of that said, since the coils are wired hot to both the primary and secondary windings you will me able to measure a voltage present at the spark plug with the ignition on and the engine not running.

 

As to what Yamaha does with the old test equipment from the factory floor, Most places will put it into storage for a while until it gets in the way and then destroy it to protect any proprietary design info.

 

In the past I have tried to buy tooling and info for a discontinued items and there was no way they were going to sell it.

[snyper316]

Ok that makes sense as to y I got bit can't I just put points in the bike

 

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[bongobobny]

Yup! The coil is an "autotransformer" which is in reality a very big coil with a "tap" on one side of the coil to make it act as a primary winding. As Jeff stated, the TCI opens and closes the ground to the primary side of the coil, and 12 volts is always on with ignition on. Now, theoretically because the voltage applied to an open circuit is the same at whatever point along the circuit you measure it, you should see 12 volts at the end of the coil, and at the plug side of the plug wire...

[snyper316]

Not no more I don't but I can now hold metal while I crank it and it tickles

 

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[snyper316]

But it's not something I will do with a good TCI I would prolly get knocked on my ass

 

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[cowpuc]

First we have to be on the same page with terminology.

The pick up coil is located down by the Stator and it is what tells the TCI the location of the crankshaft and the RPM of the engine.

The TCI uses the information from the pick up coil to decide when each plug needs to fire. Since the coils are all wired hot the TCI controls this by switching the ground on and off. At the moment that the ground is taken away by the TCI is the moment that the spark plug fires. Each ignition coil has 2 windings of wire, the primary and secondary. The primary is the one that the TCI is controlling the power to. When the power is flowing through the primary it is an electromagnet and builds up a strong magnetic field. As soon as the power is turned off BY the TCI that magnetic field collapses, it is the magnetic field that is collapsing around the secondary winding that actually creates the spark voltage for the plug.

 

With all of that said, since the coils are wired hot to both the primary and secondary windings you will me able to measure a voltage present at the spark plug with the ignition on and the engine not running.

 

As to what Yamaha does with the old test equipment from the factory floor, Most places will put it into storage for a while until it gets in the way and then destroy it to protect any proprietary design info.

 

In the past I have tried to buy tooling and info for a discontinued items and there was no way they were going to sell it.

 

Yup! The coil is an "autotransformer" which is in reality a very big coil with a "tap" on one side of the coil to make it act as a primary winding. As Jeff stated, the TCI opens and closes the ground to the primary side of the coil, and 12 volts is always on with ignition on. Now, theoretically because the voltage applied to an open circuit is the same at whatever point along the circuit you measure it, you should see 12 volts at the end of the coil, and at the plug side of the plug wire...

 

All this brings another question to mind for you two guru's... I was always told that with non-contact point ignition it is really hard on the ignition system to not have the spark plug(s) grounded to allow the coils to discharge a spark across the air gap if you are doing engine work and need to spin the motor over with the ignition on (for doing a compression test ect..).. Is there any truth to this or is it ok to just leave your plug wires hanging empty with no plugs in them and opportunity for the coils to discharge? Any of that make sense???

 

After reading all the stuff about Snyp's situation,, I cant help but wonder if it's a coil problem OR, maybe a bad connection at the 12 volt input into the coil's,,,, Snyp,,, can you take an ohm meter - stick it on DC Volts and check the leads going to your coils - maybe your just dealing with a corroded connector somewhere...

[snyper316]

And do it with voltage and test the voltage

 

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[snyper316]

I'm getting -0.09 on coil connections with just the key on but if I remember right I got 12 volts going to TCI it's just not coming out that way I just measured resistance coming from plug it all measured in specs and switched the coils last night to see if I could get spark from no. 4 which I did get spark. It just wouldn't make sense 4 the coils to just die I may have confused some by asking the questions.

 

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Edited July 25, 2016 by snyper316

[snyper316]

I haven't taken the TCI board out yet but is there capacitors on the board and should b 4 heat sinks in there one for each circuit and seems almost like diode problem

 

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[snyper316]

That's if memory serves me correct from working at the coin ops

 

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[snyper316]

But would need the board tester that Yamaha probably destroyed

 

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[snyper316]

The main function of a diode is to block the current in one direction, and allow current to flow in the other direction. Current flowing through the diode is called forward current.

 

There are several types of diodes:

Rectifier diodes -- these are the most common, with its function described above.

 

Detector diodes -- these are more sensitive than normal rectifier diodes. They are used in radios and televisions to convert radio signals to audio or television signals.

 

Zener diodes -- These diodes are the opposites of the normal diodes, because they are designed to conduct current in the backwards (reverse) direction BUT only at a very precise voltage. Zener diodes are used to regulate voltages (to behave sort-of like a battery).

 

Capacitance diodes act as tunable capacitors and are also used in radios and TVs to allow electronic automatic tuning.

 

Tunnel diodes are used in oscillator circuits

 

HOLY CRAP ALL THOSE BANGS TO THE HEAD DIDNT HURT MY LONG TERM MEMORY LOL

[snyper316]

You know cowpuc you got me thinking about one thing but then i read the BIG RED letters in a post I did recall i wasnt getting ground to my tci unit on pick up coil side and sure enuff i wasnt but... read the big red letters that told me that I wouldnt have ground if the plug was not plugged in... Dang it Man you got my hopes up i was gonna get to ride today........ but only if I