Dying at idle with brake or blinkers on

[greatnw]

I' ve been enjoying riding most every day for a couple of months now. Touched most systems and performed mods or repairs.

Last weekend I started having a new problem. I had the idle set a little low and the bike starting dying at idle. I bumped the idle up to temporarily override the problem but then I noticed that if I held the brakes on or had the turn signals on that the bike just died instantly.

Sometimes it took a few seconds before I had power to start again.

I haven't run the charging systems diagnostics yet. I have cleaned all the connectors and rechecked and cleaned the ones behind the fuse box again last night.

I can run the brake lights and turn signals no problem with the bike not running.

Can't find this specific problem in any posts so I thought I'd run it up the flagpole.

Thanks

[Schming]

Flag at Half Mass

Start with the battery and a multimeter and check D.C. Voltage not running and running and let us know what you find.

[XJOK2PLAY]

Also, is your tach working during all this? Tach is related to charging issues sometimes...

The chart on my XJ calls for the idle speed to be set to 1100 @ idle.

They can discharge at idle if it's set too low...

I found the chart on the inside R.H. side cover on mine.

Do the earlier model XS's call for that high idle rpm?

I know the XS system puts out less amps than the XJ's.

By 1982 they were heavily changing things in the carbs and trying to meet emissions standards...

A fully charged, good working battery voltage should be between 12 - 12.5 volts, bike not running.

Should be around 13 running at idle, up to 14.5 or more at 2500 - 3000

Sounding like low or no charging output or a bad ground point... I'd check charging voltage as previously suggested next.

Voltage has to be certain amt. to make the TCI work for the ignition system. I think it's 12 + volts... TC knows for sure...

[greatnw]

12.6v at the battery not running.
12.86v running
12.86 v at 4K rpm

Should have bumped to about 14v shouldn't it?

[XJOK2PLAY]

It woulda been nice to see more...

Did you by chance try your signals at idle while watching battery voltage?

I've seen many times in my career as an electrician, voltage will be present until a load is applied and it tries to pass through a bad connection... then it vanishes... sometimes will come back, once the load is removed.

It sounds like that could be happening, which is affecting the voltage to the TCI and the coils.

Don't you love electrical Gremlins???

JAT
Good luck, and keep hangin' 'til you score... it's a great feeling.
Bob

[greatnw]

It really should have jumped up, shouldn't it?

I am not the best at the electricals but I can do them.

I thought about the fact that I should have checked it it with the blinkers and brakes. I'd already buttoned it up and am heading to bed.

[Ivan]

12.8 at 4k makes me wonder if there is an internal problem with the battery. I would definitely pull it and have it load tested. A quick and dirty load test is to disable the ignition and put your volt meter over the battery terminals and watch teh voltage while cranking the engine. If the voltage plummets after a few seconds of cranking, chances are the battery is done.

[XJOK2PLAY]

Good call, Ivan... he could have a bad, dead, or broken cell...

I bet when the load's applied to it, the voltage drops below what the TCI has to have to function...

(Hope things keep getting better for ya, Ivan. It's great to see you back on more!)

[Schming]

"Touched most systems and performed mods or repairs. "

Have You inspected, cleaned,repaired if necessary, lubed with dielectric grease every electrical connection including grounds? Don't forget to take apart your turn signals and brake light as the brass on the bulbs tend to corrode also. HTH

[oldyam80sg]

That happened to me a while ago.Battery showed 12.5 volts at 4000 rpms-did not increase.A trip to the auto parts store on the machine confirmed something wrong with the battery.I bought anew battery at Wal-Mart and after charging it showed 14.5 at 4000 rpm.Battery that i had was less than a year old.

[oldyam80sg]

I think it has been posted numerous times that you don't want to put dielectric grease on grounds.

[greatnw]

This is why this forum is amazing.

I'll be yanking my new (4 or 5 months ago) sealed XS battery from Mike's XS and having it checked. If it's bad it'll be a Wally World wonder replacement until I know I have the other stuff sorted out.

The only other thing I can think of is that my starter solenoid is a little flaky. But it is either all on or all off isn't it?

[oldyam80sg]

Yes i think so.I have a spare one to try out and a spare starter.After the battery was confirmed to be bad,i replaced it and have not had a starting problem since.Good luck!

[CatatonicBug]

I think it has been posted numerous times that you don't want to put dielectric grease on grounds.

I can't imagine why this would be the case. An electrical circuit is a loop, and you want the loop to have no lose ends. Wouldn't greasing the grounds be just as important as greasing the other connections??

[TopCatGr58]

Hey Bug,

Dielectric grease is an INSULATOR, and IF it gets between the metal parts that you want to make contact, it can actually inhibit current flow. For the large grounds and such, you want to clean the contact surfaces, put the parts together, and THEN you can slather the Dielectric grease AROUND the connection to seal it from the elements/corrosion.

However, that said, the type of bullet connectors that our bikes use can make it hard/difficult to apply the grease around the outside once it's reconnected, and the pressure of the bullet style connectors should squeeze the grease out from inbetween the metal parts when they are connected.

What I had warned about using the grease on primarily were the spark plug high tension leads and where the plug caps screw into them, not wanting to cause anymore resistance in that circuit.

Hey GreatNW,

That voltage not running sounds fine. I know what has been posted about bad batteries, but sounds also like the Reg/Rect may not be working properly. If you take a tap wire and tap into the light green wire on the Reg/Rect connectors and put it to ground, and then check the charging voltage at 2.5k. IF the charging current goes up to the 14.5 level or more, then the Reg/Rect is suspect. But make sure that you first take the REG/RECT off the frame, clean the frame contact points, as well as the securing bolts and wires, and both sets of connectors. ALSO charge your battery overnight before doing these tests.

T.C.