Overcharged but won't turn starter?????

TCI is Transistor Controlled Ignition, where CDI is Capacitor Discharge Ignition. While they both perform the same basic function (triggering coils) they do operate differently.

TCI was an improvement over the CDI and is what the 80s XJs have.

By 1990 Yamaha was going to computerized ignitions. This is what the SECA II seems to have as it has a single pick up coil.

Generically Yamaha seems to refer to them all as igniters.

I'm completely at a loss how a charging system running at 15V (in spec) can result in a battery that reads 22V when shut off. The battery should be discharging into the electrical system in that circumstance.

 

Um...yes, you did say the battery was dead but my post was to point out an obvious error in your information. If you don't know what you are talking about, please, PLEASE don't fire off with mistaken information without prefacing it first with "in my humble opinion" or "I'm not 100% certain about this...". It's ok to quote sources when possible, it adds to the validity of the statement. We aim to educate folks here and we do that by explaining things as clearly as we can with valid knowledge.
If my explanation was too in depth, just say so and I'll gladly rephrase it to better meet the needs of our inquiring audience. Let's get back on track with the issue at hand please.

 

‘22’ on the digital meter may really be 2.2 (two point two)
No starter turny at 2.2 volts.

I have an electronics background. I have maintained my own automotive batteries for years. I did a quick Internet search to see I’m missing something.
I feel very confident you will not get more than 13 volts from a static 12 volt battery.
13 volts is being generous accepting some degree of error in meter or reading.

MN-Maxims questioned if you are attempting to revive old, broken or somehow bad battery. I am beginning to think that is the issue. If the battery was deep discharged (2.2 volts is deep) and especially if let sit for days in deep discharge, then the battery will be permanently damaged.

I have not seen posted that you have attempted a known good battery, either on the bike or to test meter(s) readings.

Post-post:
Possibly .22 (point two two) volts. If the digital meter is auto-ranging, it is easy to mis-read.

 

Mdee, good points all^^^. I agree with the static voltage, I've never seen more than 13.8 on any 12 volt battery, even new.

 

The reading was in excess of 15v as thats all the meter reads upto'
I thought the igniter was a different part again - a sort of spark booster in the ignition system - I have one of those too.
This 22.1v did eventually drop to around 13.5v,
and would it discharge any other way if the reg/rec was duff?

 

I have had this digital meter for in excess of 10 years, I know how to read it, I know what a decimal point is, It doesn't auto select range - it has a dial
The meter was initially set to read upto 20 vdc, it started at around 12-13v then slowly (roughly at 0.1 per second and getting slower over approx 2 mins) climbed to read '1' so I had to turn it up a step to 200 vdc range and it then stopped climbing at 22.1v, I merely read what it displayed - I don't know WHY it read 22.1 volts, and why would I lie?
The battery was connected to the bike at the time and the ignition was turned off, the battery is NOW showing 13.3 volts (I have not removed it from the bike yet as it hasn't stopped raining for long enough).

 

No worries Dub, we are just making observations and comparing notes. I confess, your problem is the first time I've ever heard of a battery outputing that much voltage in a static state. A real brain-teaser...
A thought just crossed the mind, does the meter have fresh batteries in it? I've seen old batteries in meters lead to wonky readings.
The only way I could see the battery doing this is if it had been overcharged (and do I mean overcharged!). I'd put a call into Yuasa and ask them what gives. I'd also be doing an alternator check once the new battery is fitted. If you don't have any odd readings out of the charging system, you have a mystery on your hands.

 

What about the readings I got of roughly 6.2v at each white wire from the alternator? at revs between 1000 -2000, (I got no tacho)

 

I don't think the Alternator on any XJ-Bike is going to make anything close to 22 Volts.

If I had to place a bet on how 22 Volts came into this discussion, ... I'd bet on:

Meter on wrong scale.
Misread meter.
Operator inexperience troubleshooting electrical.

 

TOPIC NOW CLOSED.

 

[quote="Jay~Dub]What about the readings I got of roughly 6.2v at each white wire from the alternator? at revs between 1000 -2000, (I got no tacho)[/quote]
Was that AC voltage or DC? I don't have my book handy so troubleshooting is a bit of a pain at the moment.

 

Was that AC voltage or DC? I don't have my book handy so troubleshooting is a bit of a pain at the moment.[/quote]

Read at DCV setting

 

Read at DCV setting[/quote]

White wires have AC output from the stator. You would read between two of them with the meter set to AC. I don't believe Yamaha has a spec for them. Since it's a field coil alternator the output will depend on how the regulator/rectifier energizing the field coil. I've only seen AC output specs for fixed magnet alternators.

If you're pegging a 15V DC gauge at the battery at 2K RPM or more your stator and rotor are fine. You need a meter that will read higher so you know what the charging voltage really is. I don't have the book here but I believe the spec will be below 16V. If you're high it'll be the regulator/rectifier or the wiring to it.

 

digital meters require batteries. usually 9v. i've seen meters do funky things if that 9v battery gets low.

if your meter runs on battery. might try a fresh battery.

the manual doesn't give specs either. just says 14v 19A @ 5000 rpm.

 

Thanks, I will see what the weather is like later and I would like to re-do some tests so as to confirm my previous results, as I am getting a bit p*ssed off with other people making out that either I don't know what I'm doing, or I'm lying or don't know how to look at a test meter... Its getting just a little bit tedious, so I'll take a break until I know more.
Thanks to everyone else for all the positive input though.

 

Update:
FIRSTLY! - thank you to everyone for your input.
Right..., cleaned and inspected all connections,
Starter solenoid: contacts were slightly burned and pitted.
Reg/rec connection block: the terminal with the red wire shows a definate sign of overheating, i.e. the spade connector blackened and the surrounding plastic slightly melted.
Repaired some dubious looking connections.
Bought a new test meter.
fitted new battery.
replaced starter solenoid and reg/rec (from an XJ900).
at low revs, its reading 13 -13.90v and now showing an average 14.30v at 60 mph in 5th, at the battery terminals,
Does this all sound OK now?
I would like to do a proper AC voltage test on the generator, it all seems to be working, but as I just bought a new meter I should make good use of it!

 

Sounds just about right. Glad you are pressing on with the project rather than giving up. Alternator should be outputing about 40 volts peak-to-peak (from the calculation of 14vdc regulator output and this conversion formula (RMS x 1.414) x 2=P-P). You would measure between any two leads of the alternator output.
Good luck and enjoy having a nice new meter, they can be a great tool!

 

but the meter is only going to read about 28.2 vac/rms

 

Please Robert, my head! I'm just a welder!.
- (RMS x 1.414)???
do I test between any 2 white wires from the genny, at the AC setting, or all wires i.e. 6 readings?
I never give up btw, I always win, somehow. :twisted:

 

AC volts 3 readings, call the wires a,b,c you read
a-b=
a-c=
b-c=