Electrical Problems

The issue:
Whilst riding the bike will lose power - this tends to be gradual with some spluttering or can be just a loss of power under throttle then nothing, when this happens tachometer will fluctuate wildly.
Will pull over and sometimes it will start, after doing the sounds like a flat battery thing, other times I've had to push start the bike.
After my last ride where this happened 4 times I've got to fix it before I ride again.

When trying to start the bike it sounds like a flat battery but isn't. There is a whirring sound, the starter may turn over slowly, like a flat battery would turn it and the tacho will fluctuate to 3-5,000 rpm but no start.

Now I just get a clicking from the starter solenoid with no starter motor crank.

What I've done:
Replaced the original fuse holder with posi-lock in-line fuse holders.
Checked the alternator brush length (OK) and cleaned the rings.
Did the Gamuru's "How to test your starter circuit" - all passed
Pulled the fairing off and replaced most of the connectors with posi-lock weathertite connectors
Cleaned remaining & used die-electric grease on all connectors.
Re-did Gamuru's "How to test your starter circuit" - this time no cranking of the starter motor when I short the solenoid out and fails the neutral switch continuity test (even though the neutral switch light is OK and actually will not start in gear)

What I'm going to do tonight:
Check & clean the negative earth wire
Check the starter cut off relay - there's a testing procedure in the Haynes Manual

Any thoughts or suggestions are welcome as it's starting to drive my wife crazy

 

fluctuating idle? My bet is air leak. Who's with me?

 

Not me - I re-read his post twice and nowhere did he mention the word idle :lol:

Also, nowhere in his post did he mention anything about the battery. Is it fully charged? Holding it's charge? Is the bike charging the battery when running? Will it start with jumper leads? 'Cause it sounds like a charging problem to me, rather than a starting problem.

 

Tested the starter cut off relay according to the manual and no problems. Resistance from battery negative to frame checked OK 0.5ohm.

I've had the bike only a few weeks. The PO owner assured me battery was 6 months old.
Bike's been idle for a couple of weeks and I drained the battery when I left the ignition on one night "doh". Recharged and tested about 12.7 volts. Have put the battery on a trickle charger for now and will test once charged - was showing 10.6 volts but I've been doing a few starting tests to no avail.

Hooked up a multimeter to the battery
11.5 volts - ignition off
5.8 volts ignition on, neutral and trying to start
Pushed started the bike
At idle 1050 - 1100 RPM - 14.46 volts
At 2000 RPM - 14.65 volts
At 3000 RPM - 14.70 volts

Looks like I need to get the battery tested for a start then investigate how to test the regulator.

 

Charging system seems OK from those readings. Try to start it with jumper leads off your car (just make sure the car isn't running). If it fires up, you've got a weak / shot battery. If not, check all the wiring and test the starter motor.

 

11.5 is an indication that the battery is weak. The 5.8 when trying to start tels me the battery is "dead" and should be replaced. A fully charged battery should be in the 13 volt range and cranking voltage should be 9.5 to 10 volts.

If you put a known good battery in the bike and cranking volts are less than 9.5, the indication is that the starter is drawing too much current, possibly shorted armature.

The 14.6 volts tells us the charging system is OK

 

Crow, my impression is that you need a new battery based upon your static and starting voltages.
The goofy tach could either have an ignition pickup going bad or your TCI is giving you grief.

 

Sorry. Fluctuating tach. Now you can see where my first thought was idle.

 

NP jarreddaughtry

Thanks for the input guys. I'll pickup a battery over the weekend and see how that goes. Looks like I'll need to check the ignition pickup and I suspect have the TCI unit rebuilt sometime in the future.

My better half wanted me to take the bike to a mechanics to be fixed but I'm having too much fun working it out myself and I haven't even started on the mechanical side of the bike yet.

 

i'm kinda leaning with robert, batt, but pick-up coils or maybe primary
coils be going so check coil resistance before spending $70.00 on a
batt.

 

Crow - before you go and buy anything, try and jump start it with another battery. Seriously - you're only guessing until you've tried this (although it's a 90% chance your battery is shot).

And from memory, I think one of my old XJ9's had the fluctuating tacho when I tried to start it when the battery was down on charge, so I don't think this is anything to worry about.

 

Ducked home at lunch time and tried your suggestion Hillsy. Bike had been on a trickle charger all night so should have been good to go. Pressed the starter and just a groan.

Jumped the bike from my car battery (car not running) turned the ignition on, pressed the starter and she roared into life

So new battery on the way.

Now will have to run some checks to see if there is an overcharging problem. For example I still need to work out how I've got a 14 odd ohm reading at the connector end of the rotor but the correct resistance across the rings themselves.

 

$AUS180 for a new Yuasa battery!! Salesman reckons don't buy the cheap ones unless you plan to sell the bike.

Looks like I'll have to do a bit of research....

 

A salesman would say that.

You should get about 2 years out of the cheap battery if you make sure you fully charge it before you put it in the bike. It does make a difference to the life of the battery when you do this.

What is the warranty on the Yuasa? 12 months?

 

I had the same problem but it was much worse at about 35ohms. It turned out to be the alternator brushes had some of that really fine green corrosion on that mesh/fine strand wiring that comes off of them for connection. You can't really clean it off either. Get some new brushes, I bet the problem goes away.

 

Here's a cheapie on eBay:

http://cgi.ebay.com.au/Battery-Yamaha-F ... 842wt_1074

$79 shipped. 6 month warranty.

 

Right picked up a new Yuasa battery YB14L-A2 and will install it tonight or tomorrow depending upon time.

I'll also pull the alternator cover off again and check the brush holders as per your suggestion BDM - the problem is certainly between the brushes and the connector.