I have an '85 YFM200 ATV that won't start with the electric starter. It runs fine with the pull start though.

I have replaced the battery and starter and when I hit the button, I still get nothing. With a voltimeter on the battery, when I hit the button it drops from 12.4v to 0v, then slowly climbs back up. I followed the procedure in the Clymer manual of turning on the headlight (which works when the ATV is running via a pull-start) and hitting the button and the light doesn't come on either.

So the procedure says to check the battery charge and connections and then the starter connections at the battery, solenoid and starter switch. The battery charge is fine and the connections seem to be as well - inline fuse is good, and I get the neutral light within a couple seconds of turning the ATV on. Starter connection is good, it's only the one wire and the starter itself is new. The switch seems ok, since the battery voltage does drop when pressed.

I'm out of ideas, what else should I check? There is a lot of dirt from the previous owner underneath, but all the connections are in plastic plugs and appear to be in good shape. There is one wire hanging down the back of the engine, has a C connector on it and does not match any others on the ATV, nor can I see anywhere it should be connected. Any thoughts on what that might be from? Should I ground it?

Any advice is appreciated! Thanks!

- rob

 

You could try jumping it off of a car battery or a battery that you know is good. Check the voltage at the starter, using the engine as a ground for your tester lead. The engine has to be grounded to the ground terminal on the battery with a wire as big as the starter wire. (probably 8 or 10 gauge).

If all of that is good, you could take the wire off of the starter and hit the starter button to see what the voltage does then. If the voltage doesn't drop then, there may be a problem with the starter. You could also try to send 12 Volts straight from the battery to the starter terminal and ground the starter straight back to the battery ground. If it doesn't turn then, you know there is a problem with the starter.

 

The starter ended up being fine, it appears the issue is the starter solenoid. I ran some tests I found in the Clymer manual and found that the starter solenoid does not test like it should; I got no reading across the starter leads like I was supposed to. I also did not get 12V at the starter when I hit the button, so the problem is somewhere between the button (which I did test and is supplying 12V when pressed) and the starter.

So I am replacing the starter solenoid. I am not sure if the relay is good or not; it clicks as I would expect but the tests in the manual are inconclusive - it shows two different relays, not sure which I have and neither tested right. I will probably just replace that as well to be sure.

I also figured out what I think the "random" wire hanging off the back is - the reverse light indicator. Except I don't think there is an indicator light on my panel for reverse - only two lights, neutral and I assume the red one is oil temp? Plus I can't find any place within the length of the wire that it would connect.

 

A bad solenoid usually will not make the voltage drop to 0. You should have 4 wires on the solenoid, 2 big wires and 2 little wires. You should have 12 volts at the 2 small wires when the starter button is pressed (1 small wire is ground and the other small wire is 12VDC +). You should have 12VDC+ all the time to 1 big wire (the 1 that goes to the battery +) and should have 12VDC+ on the other big wire only when the starter button is pressed (solenoid will click). The solenoid just passes 12VDC positive from the + terminal on the battery to the starter on the big wires when the starter button is pressed.

The red light should be your reverse light. Most Yamahas ground the wire at the reverse lever only when in reverse and send that ground back up to the reverse light.

 

I have no voltage on the small wires on the solenoid when I press the starter button. I followed the test in Clymer to diagnose the solenoid; using an ohmmeter I measured across the big wire terminals when pressing the starter button. I got no reading when I should have gotten zero. The solenoid also does not click when I press the button, and I checked the wires and they are all undamaged. When I did the resistance check on the relay, I also got no reading there. According to the book, these things indicate the solenoid and the relay are bad, so I've ordered new ones. I hope they solve the problem! I have also since found the red light should be reverse just like you say, and there is supposed to be a reverse switch just behind the neutral switch on the bottom of the engine. I haven't been out to the garage to check this out yet. I will, but it is secondary since its not part of the starting issue and this is just going to be a pit vehicle, so the reverse indicator isn't as important as it would be for an ATV that's really ridden. Many, many thanks for your assistance with this! As you can probably tell, electrics are NOT my thing.

 

Electronics may not be your thing, but at least you have a meter and know how to use it! That's more than a lot of people can say. I found my old Clymer manual for '83-86 YFM200 (I had one years ago) and was looking at the wiring diagram. You will need to get 12 volts to the 2 small wires on the starter relay when the start button is pressed. This voltage comes from the start relay, which comes from the start button, so even if the starter solenoid is bad, the new one will not do anything until it gets 12 volts on the small wires when the start button is pressed.

There is a neutral safety switch on the motor with 1 wire going to it. This wire should be grounded only when the engine is in neutral. This turns on the green light for neutral and activates the starter relay. If that doesn't work correctly it will never start with the starter.The positive for that bulb comes from the main switch anytime the switch is turned to 'on'.


The reverse light is for information only, the reverse switch on the motor grounds out when in reverse and sends that ground up to the red light. The positive for that bulb comes from the main switch anytime the switch is turned to 'on'.

There should also be a fuse on a wire going to the + side of the battery. Make sure it is OK. If the green neutral light will come on in neutral, the fuse is OK and the neutral switch is good. If all of that is OK, it could be the starter relay that you have ordered, hopefully that's all it is.

 

Well, I wouldn't say I really know how to use a multimeter but I can read a manual and follow directions.

The neutral light is working and I already checked the fuse (simple things I actually understand first, then move on to harder diagnosis) so hopefully, the relay and solenoid I ordered fix the problem.

I will keep you posted. Thanks again for all the help!

 

ARGH!!! I am really frustrated.

I replaced the starter relay and solenoid. I get the same click from the new relay when I hit the starter button, but still no start. I checked for 12VDC on the wires from the relay when I hit the button and I think I have located the problem. With no solenoid attached, I get the 12VDC in the plug like I should. But, when a solenoid is attached (old or the brand new one) I do NOT get 12VDC on the small wires when the starter button is pressed. This is without the big wires attached, but that shouldn't make a difference, I should still get the 12VDC from the relay plug into the small wires even if the solenoid is bad, right?

I am not sure what to try next. Is my new solenoid bad?

 

The starter solenoid is probably not the problem. You should get 12V on the small wires at the solenoid whether the 2 big wires are connected or not, and you need 12V on the small wires when the wires are connected. Multi-meters can play games and give you crazy readings by picking up grounds through electrical components, so don't be confused by this.

If the starter circuit relay (small relay, not the starter solenoid clicks) then you should have 12VDC+ on both red/white stripe wires and the blue/white striped wires (according to my wiring diagram here). The light blue wire should be the only ground on the relay and should be grounded only when in neutral (neutral light should be on, ground comes from neutral safety switch).

The blue/white striped wire leaves the starter circuit relay and should go through a plug with 2 black wires, the blue/white wire, and a red/white wire to the starter solenoid. The red/white wire in this plug should have 12VDC+ only when the starter button is pressed and both black wires in this plug should be grounded when the main switch and the engine stop switch are both on.

It's seems that you may not have a ground to the starter solenoid (black wire). It's hard to tell by this diagram where the ground originates, but it looks like it comes from the magneto and most of your electronics run off of this ground. If the headlight, taillight, and engine stop switch all work, then you do have a ground, but maybe it's just not getting through the plug for the starter solenoid? Mud and water have a tendency to get in the plugs and corrode the terminals.

To check for ground, you can use your volt meter, put your positive lead on a known 12VDCV+ source (battery + terminal), and put your negative lead on the ground wire you are testing. You should get a reading of around 12V when you have the ground.

You could also try temporarilly? to connect a ground from the battery - terminal to the black wire on the solenoid, and see if it cranks then.

Hope I haven't complicated an already seemingly complicated problem, but I think there is a simple solution to your problem, just finding it is the hard part.

 

Nope, what you say makes sense; I've been told by others that the likely culprit is a bad ground. Finding it is the tough part and my electronics knowledge isn't strong enough. For now, I have decided to punt; since it's running there is a lot of interest in it on CL as it's not a horribly expensive quad and if they aren't as picky as me, the fact that it needs to be pull started isn't a big deal. If it goes, then it's one less project in the garage. If it doesn't, I will pull it all apart again when I have some time and a clear head and try to find the bad ground. Thanks again for all the assistance!!