If you're doing a true voltage drop test, you WANT to see 0v. Voltage is a measure of difference, so you would want to see 0 difference from the battery + to the starter lug with the starter button pressed.

If you see 6 volts for example, it means you are losing 6 volts somewhere between the battery and starter.

Edit: If you're just measuring the voltage at the starter lug (black probe on the battery -, red on the starter lug) and you are getting 0 Volts, that's a bad thing. In that case I would look more closely at the solenoid.

 

Are you getting the same results with jumper cables?

 

Are you getting the same results with jumper cables?

Yes, I get the same results with the jumper from the car.

If you're doing a true voltage drop test, you WANT to see 0v. Voltage is a measure of difference, so you would want to see 0 difference from the battery + to the starter lug with the starter button pressed.

I'm still having trouble with this concept. As I understand, when measuring between the battery + terminal and the starter motor, voltage drop is the DIFFERENCE between the voltage before and during the time when the starter button is pressed. From the manual I understand that we want there to be very little voltage drop. But I am getting complete voltage drop.

Before pressing the button the reading is 12.4V. WHILE the button is pressed the reading drops to 0V. AFTER the button is released the reading comes back up to 9.4. It stays at 9.4 until I disconnect the wire from the starter motor.

 

You are getting only 9.4 volts with a car battery hooked up to it?

 

You are getting only 9.4 volts with a car battery hooked up to it?

Yes, 9.4V is the reading from the battery to the starter motor AFTER I have pressed and released the starter button.

 

It sounds like both batteries are bad if you are only getting 9.4v at the car battery too. That or there is one heck of a short somewhere.

 

I know the batteries are fine. Late last night I started thinking about a short as well.
Before the button is pressed I'm getting 12.4V.
When the button is pressed I'm getting 0V. This is bad, right?
After the button is released I'm getting 9.4V

One time, but only one time, when I was putting the starter motor lug nut back on I got a spark when the ratchet touched something. I've tried to replicate this without success. But I think that overall the indications are a short. Perhaps in the starter button area?

 

Where/how are you measuring that 9.4 Volts? If that's the battery voltage it sure does point to either a bad battery or nasty short like you said. Any issue with fuses popping or melted wires? Anything getting hot?

 

Where/how are you measuring that 9.4 Volts? If that's the battery voltage it sure does point to either a bad battery or nasty short like you said. Any issue with fuses popping or melted wires? Anything getting hot?

I'm measuring it from the battery + to the starter motor bolt, AFTER pressing and releasing the start button. I believe that this should read the same as the battery both before, during and after pushing the start button. Is this correct? I have not found any hot wires.

 

If you're measuring that way, you should get nearly a 0v reading WHILE the button is pressed - voltage should be equal from the battery to the starter lug, hence a 0 reading. What it reads before and after depend on how the starter is built.

Try measuring a different way. Measure from the battery - to the starter lug. You should get a 0v before and after the starter button is pressed, and get roughly battery voltage when it is pressed.

 

So my concept of "voltage drop" has been completely wrong. I have been looking at "voltage drop" as the amount that the voltage dropped during the test. i.e. from 12.4 to 0, indicating a drop of 12.4V when the book says there should be close to 0V voltage drop.

Try measuring a different way. Measure from the battery - to the starter lug. You should get a 0v before and after the starter button is pressed, and get roughly battery voltage when it is pressed.

I did this test and got exactly what you were thinking. 0V before and after the button is pressed, and 12.3 When the button is pressed.

So, this still does not solve my basic question, of why the motor won't start? And why does the + to starter motor read 8.4 AFTER I have pressed and released the button. Any ideas?

 

When you're getting 8 or 9 volts measuring the way you are, you're measuring your battery voltage (from +) using the starter lug as a ground. This will give you a reading, but you have to measure through the starter brushes, which add resistance - lowering the voltage reading you see. You're measuring battery voltage, but with a really poor ground. I have no idea why it's different after the button is pressed from before. I hate electrical work!

As for your starter issue, if you're getting battery voltage to the starter with the button pressed, and you've tried multiple batteries/jumper cables and it still won't turn over, try jumping the two posts of the solenoid. They make remote start trigger switches for this, or you can use a wrench or screwdriver to bridge the two. It will arc and you need to be careful. If the starter still doesn't turn over, it's time to consider pulling it and rebuilding/replacing it.

EDIT: Be careful with this. I don't know how sensitive your bike's electronic brains are. Sometimes these can be damaged by arcing things - jumping the posts may not be a good idea.

If you have access to an inductive ammeter that would be a good tool to use at this point, also.

I could be missing something here - text is no substitute for being there - but that's my current thinking.

 

Did you try jumping power directly from the battery to the starter post with a jumper cable?

 

Did you try jumping power directly from the battery to the starter post with a jumper cable?

No, I have not tried it. Can you please describe it exactly. Do you want me to take the jumper cable from the battery + to the starter motor lug nut and then press the starter button?

 

No button pressing is required. Disconnect the starter cable so you just have the bare lug. Clip one red clamp on the battery + and touch the other red clamp to the starter lug. (It will arc - be careful.) As soon as you touch it the starter should turn over. If it doesn't suspect a starter issue.

Again, don't go too nuts as the arcing probably isn't good for it.

 

Got a nice spark when I accidentally touched the clamp to a piece of the engine. But nothing when I touched the starter lug. So this is a good indication of problems with the starter motor?

 

Ya, be careful with that!

Yes, I would strongly suspect something is wrong with the starter. Check the battery negative cable both at the battery and where it attaches to the bike, as well as any other grounds - you might get lucky and find a bad one. Beyond that my guess is something is wrong with the starter. It gets juice but doesn't move.

You're SURE that's a good, charged battery, right?

 

You're SURE that's a good, charged battery, right?

Although the bike sat all winter, I started it and let it idle once a month. Also I've had a charger on it all week and I've also boosted from the car in these tests, so I'm thinking the battery can be ruled out as a problem.

Also, a week ago I was attempting to start the bike and it turned over very easily for a few seconds. I stopped pressing the start button to let it rest for 5 seconds, then when I pressed the button again I got only the relay click. So whatever it is that happened, happened in the 5 seconds between those two attempts.

 

Interesting. Do look for dirty grounds or bad connections before you go too nuts removing the starter. Also, it might be a good idea to verify the engine will turn over by hand, either with the rear wheel or with a wrench on the crank (look up in the manual how they want this done - usually take the plugs out and use a wrench).

Just trying to think of easy things to check before taking things apart.

 

Try to give focus on for dirty grounds/bad connections before you go too nuts removing the starter. To verify the engine will turn over by hand, either with the rear wheel or with a wrench on the crank.
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Before you go crazy with the disassembly, try "rapping" on the starter. I had friends who had "fair weather cars" that never got touched from September till March. I'd get calls to come look at their cars all the time.

From sitting, the brushes (contacts) inside the starter would get a little corrosion and not make good contact. I'd take a small ball peen hammer and tap on the starter while they held the key....

Note 1 - when I say hit it with a hammer.... I don't mean to pound the hell out of it... I mean tap it slightly harder than starting a nail into a board. Keep tapping it while someone holds the start button... If it starts or tries to crank you're on the right track.

Note 2 - I've never had a motorcycle starter apart but I'm assuming they are just smaller versions of car starters and therefore they work the same way.

 

RaconLdr: Your geniosity is unsurpassed. It took exactly one tap with the hammer to start working. Thanks very much to all who helped. I'm up and running again!

 

Glad to hear that.... Keep an eye on it, it will get worse over time.

 

Good, Foolish. Your starter may need to be rebuilt or replaced soon, though. Usually that's not a good sign when starters need some persuasion.