1982 XJ550

Bike was running great when I parked it for the winter. New battery in Oct. and parked in Nov. Trying to get it going for the spring and I'm having starting issues. It is very cold blooded and it usually takes a bit to get it going. But this time with the battery fully charge, I only get a few cranks and things stop. Battery is reading full charge.

Checking the ohm reading (three white wires) on the stator, the manual says 0.5 +/- 10%. I'm getting a reading of 1.1 at all three connections. When I check the ohm reading on the alternator (green & brown wires) the manual says it should be 4.8 +/- 10%. I'm getting 5.5 on both.

Manual doesn't say what to do if the readings are out of range.

Do I need to change my stator? alternator? both?


Reply to comments - Thanks to all for the great input. I will start with the battery and work from there. As to how the starter is sounding/reacting; with a full charge on the battery, the starter sounds really good but slows very quickly like the battery is losing all it's power. With such a new battery I wasn't really expecting trouble with it. I will also check all my brushes. I have never changed them and the odo says 22,000.

 

It wouldn't be the first time a battery is supposed to be full charged but doesn't deliver enough power to crank the engine with efficiency. Personnaly, I would bring the battery to a mechanic and have it load tested (I guess these are the right words).

 

Do you have a car battery of the same voltage nearby that you can just run jumper cables too just for the start? Spring is always a pain because it needs to be warm enough to vaporize the gas, and I've only had success starting the machine below 40 degrees when it was running daily.

 

You can use a car battery as stated (car not running) or I like to use my portable car battery jumper instead which are popular these days. Wouldn't hurt to spray couple of shots of starting fluid in the carbies before cranking her over. If it does start with the starting fluid then dies each time, you may have fuel delivery issues.

Edit: Advanced auto parts or Autozone will also load test the battery for you for free.

 

X2 on making sure the battery is in tip top shape - jumping from a known-good/strong/healthy 12v car battery is a good tester.

But be sure to have the car OFF when you do so.

A battery can easily have "good" voltage reading out on a DMM, but when load tested can be 100% toasted.

Try that before worrying about anything deeper.

 

Autozone will either have a small digital battery tester that measures amperage, or every store should have the B.E.A.R. tester, which is a big one that rolls around on wheels. The computer says the battery is 190 CCA but thats ridiculous, have them test it for 100 amps, its the minimum the BEAR at my local store would test at.

The only way to tell if a battery is bad with a multimeter is if the battery has a bad cell. Most batteries dont go bad from a dead cell, its from diminished cranking amperage. A battery with low amperage will charge fully to 12.7 volts, so the only way to determine its bad is to place a load test on it(to see how far the voltage drops) and watch how quickly the voltage recovers from the load

 

You didn't say how forceful the revolutions you're getting are? Does it sound weak and barely turn or is it strong and abruptly stops?

As far as Ohm readings on the stator and alternator field coil-yours indicate that it hasn't failed completely but it looks like your due for new brushes at the least. Basically it's an electric motor that is run in reverse by the bikes mill to generate E-. The higher resistance indicates more distance between the conducting bodies than there should be-if it was gone your resistance would be infinite or higher.

Always start with the battery to eliminate the easiest piece of the puzzle to check off your list. You can do a poor man's load test by hooking up your meter while cranking and see where your voltage drops to (shouldn't drop much below 10v) and should return to previous voltage within 10seconds. This is what a load tester is doing but it does it with an integrated circuit programmed to read VTS (or voltage transmission speed) and min/max V readings during a load event. Before you do that make sure it's topped off with dist. H2O and fully charged using a trickle charge (2A).

Also it's uncommon for a 12V battery to fully charge to >13V (where a good battery will go as it's being charged, then settle back to 12.7-12.6) if it has lost the ability to produce CCA-can happen but not often-such batteries usually will max below 13V and settle to 12.4 or less. More often you have one or more partially dry cells which will create resistance during cranking and sap the Amps.

 

How many miles on the bike? It might be time for alternator brushes.

The best test for the charging system is its output when the motor is running; below 2200rpm, it's all up to the battery.