Starter Issues

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Well, the OP has taken dramatic steps to resolve his starting issue. On to 2fjr.

I'll offer a few small variation on what Radio' posted.

Definitely check a recently charged battery after allowing the surface charge a chance to bleed off. The minimum time is 30 minutes (industry standard) but 4 or more hours won't hurt. It is critical that the battery has at least one cable removed to isolate it from the electrical system. An AGM like we have in the FJR should be 12.8 volts.

It is highly unusual for a stator to have an issue that would cause the battery voltage to be 13.8-13.9 volts. Usually a stator issue will cause the voltage at the battery to be around or below 12 volts.

You do need to check the charging system but I have a different approach. Unclip the battery connector from the R/R (the two wire connector with the Red/Black wires). Start the engine and measure the voltage directly on the pins of the R/R. You should read between 14.3 - 15.5 volts, 14.5 is target. If this fails low, read no farther in this step and go to the next step. If it fails high go to the last paragraph. If this passes, plug the connector back onto the R/R then back-probe the connector and measure the voltage with engine running. At idle the voltage should still be in the 14.1 to 14.4 volt range. If it is lower then something is dragging down the electrical system and it could even be the battery. We can troubleshoot this separately later if this is what you find. If the voltage is within this range at the R/R then you have voltage drops between the R/R and the battery. It is normal to have some voltage drop and as a bike ages the drops get bigger. You will loose a small voltage at the main fuse and its connector, there will be a small loss at the starter studs where the R/R wires connect to the heavy battery cables. There is a black cable that attaches to the engine block at the lower right corner, directly behind the #4 cylinder head pipe, and you can loose a bit of voltage there too.

To test the stator I suggest that a voltage test is better than a resistance test and the resistance test is unnecessary. If you have a DMM, set it for the lowest ohm scale then touch the meter leads together and read the meter. Typically the resistance of the meter leads that you are reading is higher than the .15 - .23 ohms of the stator windings making this test invalid. To mostly quote 'Howie, "Finally, switch your multimeter over to check AC voltage in the 100v range, start your bike and read the voltage coming from the stator connector unplugged from the R/R. At 5,000 rpm From pin 1 to pin 2, then pin 1 to pin 3, then pin 2 to pin 3 -- 3 separate readings -- you should see >50 volts AC on all three checks. If the rpms are lower, the voltages will be proportion but lower. If there is a serious discrepancy more than 5-6 volt at 5,000 rpm variation in the readings, then your stator is almost certainly in need of replacement." The absolute voltage reading is not nearly as important as the three reading being very nearly the same.

If the R/R output is low or >15.5 volts with the battery connector removed and the stator output tests good, the R/R is bad.

 
Last edited by a moderator:
Howie and Ion.......good info. I'll work through the tests this weekend and see what comes of it. Thanks!

 
Well, the OP has taken dramatic steps to resolve his starting issue. On to 2fjr.
I'll offer a few small variation on what Radio' posted.

Definitely check a recently charged battery after allowing the surface charge a chance to bleed off. The minimum time is 30 minutes (industry standard) but 4 or more hours won't hurt. It is critical that the battery has at least one cable removed to isolate it from the electrical system. An AGM like we have in the FJR should be 12.8 volts.

It is highly unusual for a stator to have an issue that would cause the battery voltage to be 13.8-13.9 volts. Usually a stator issue will cause the voltage at the battery to be around or below 12 volts.

You do need to check the charging system but I have a different approach. Unclip the battery connector from the R/R (the two wire connector with the Red/Black wires). Start the engine and measure the voltage directly on the pins of the R/R. You should read between 14.3 - 15.5 volts, 14.5 is target. If this fails low, read no farther in this step and go to the next step. If it fails high go to the last paragraph. If this passes, plug the connector back onto the R/R then back-probe the connector and measure the voltage with engine running. At idle the voltage should still be in the 14.1 to 14.4 volt range. If it is lower then something is dragging down the electrical system and it could even be the battery. We can troubleshoot this separately later if this is what you find. If the voltage is within this range at the R/R then you have voltage drops between the R/R and the battery. It is normal to have some voltage drop and as a bike ages the drops get bigger. You will loose a small voltage at the main fuse and its connector, there will be a small loss at the starter studs where the R/R wires connect to the heavy battery cables. There is a black cable that attaches to the engine block at the lower right corner, directly behind the #4 cylinder head pipe, and you can loose a bit of voltage there too.

To test the stator I suggest that a voltage test is better than a resistance test and the resistance test is unnecessary. If you have a DMM, set it for the lowest ohm scale then touch the meter leads together and read the meter. Typically the resistance of the meter leads that you are reading is higher than the .15 - .23 ohms of the stator windings making this test invalid. To mostly quote 'Howie, "Finally, switch your multimeter over to check AC voltage in the 100v range, start your bike and read the voltage coming from the stator connector unplugged from the R/R. At 5,000 rpm From pin 1 to pin 2, then pin 1 to pin 3, then pin 2 to pin 3 -- 3 separate readings -- you should see >50 volts AC on all three checks. If the rpms are lower, the voltages will be proportion but lower. If there is a serious discrepancy more than 5-6 volt at 5,000 rpm variation in the readings, then your stator is almost certainly in need of replacement." The absolute voltage reading is not nearly as important as the three reading being very nearly the same.

If the R/R output is low or >15.5 volts with the battery connector removed and the stator output tests good, the R/R is bad.
Dear Admins.....PLEASE PIN THIS POST SOMEWHERE PERMANENTLY....IT IS PURE GOLD FOR CHARGING SYSTEM TESTS!

Thanks for the clarifications, Alan.

 
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