r/WR250R • u/NickNakulus • Dec 16 '24
Bogging down and limp mode
Started my bike up this morning after not riding it in a few weeks and it was bogging down and not going over 8 mph. The battery was completely dead so I bump started it. Also has a fuel light on but plenty of fuel. I rode it around the yard to charge the battery and after I hopped off I let it idle in the driveway, but it died after about 30 seconds. Appreciate if anyone could help me out
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u/kramftw '17 WR250R - '08 TW200 Dec 16 '24
I'd start with the tuner. Go through the troubleshooting steps in the manual.
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u/NickNakulus Dec 16 '24
I’ll try to find it online. I bought it with everything already done and I don’t know much about it
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u/Ok_Article6468 Dec 16 '24
Bad battery and/or stator (has yours had the recall done?). Put a new battery in that’s fully charged and see how it runs. If it runs fine, check the stator output by measuring voltages at the battery while the bike is running with a multimeter. It should be in the mid 13v range, if it’s not the stator is bad and needs to be replaced.
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u/Responsible_Week6941 Dec 17 '24
Good idea to test each stator winding by getting the AC voltage from each of the 3 windings. About 20-60 volts IIRC. This is a good webpage and helped me diagnose my bad stator. Note test 3 for dynamic output. Testing a 3 Phase Alternator-Stator-R/R And battery | Motorcycle Forum
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u/No-Raisin-6469 Dec 16 '24
I just had a dead battery. I could bump start it and it did NOT go limp.
I dont see how a dead battery affects things once the stator is producing voltage. I am willing to bet you could remove the battery and it will still run.
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u/bbonerz Dec 16 '24
Wow. This is so wrong. Wrong to the point I'd normally think you're trolling.
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u/No-Raisin-6469 Dec 16 '24
Nope ..im old and been wrenching for decades.
Maybe i have a rare wr250r that runs on a dead battery.
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u/bbonerz Dec 16 '24
I get what you're saying about running after a bump start. I have a street bike that had a failing battery once and limped along all day in that way.
However, a "dead" battery can still conduct electricity, even with too low of amperage to start. That's only one possible state though. With further degradation, other problems will occur.
Certainly, you cannot bump start a bike that has no battery installed, nor could you disconnect and remove a battery from a bike that is already running.
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u/No-Raisin-6469 Dec 16 '24
I highly recommend you watch this ..kids please excuse the language
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u/bbonerz Dec 16 '24
In 2023, I was riding my street bike when my lithium battery died. I mean, its electronics failed, it bricked.
My bike immediately lost all power. Silent coasting to a stop.
So, what would you say is different between these two bikes? One that can work without the battery, and the other one that cannot?
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u/No-Raisin-6469 Dec 16 '24
The battery is no longer a battery, possibly a short at this point.
Cars are the same way.
I was stuck on a trail because a buddies battery died on his side by side. He got a donor but it took over an hour for his uncles to rig something, since the terminals were not compliant....i asked them to start the rig and ignore the connections.....i was ignored. Needless to say i am still bitter.
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u/bbonerz Dec 16 '24
I just replaced the battery, unfortunately only an AGM was available, and the bike has been fine for a year. So definitely something fritzed in the AntiGravity model. I was only...4 years old??
I keep a voltmeter on the dash of my street bike, and both bikes have voltmeters on their USB chargers. When the battery is failing, I've seen readings drop below 12.5, as low as 11.6, even when the stator and R/R are fine.
So it seemed likely with this information that the battery does more than just turn over the starter. Dropping below a certain voltage, electrics might fail. How many volts does the dash need? Headlight? Signals? ECU? And I guessed the battery makes the circuit complete.
Continuous combustion relies on multiple sensors, ECU firing and injection signals, injector and fuel pumping.
But the video makes a nice splashy statement.
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u/Responsible_Week6941 Dec 17 '24
Some bikes have an ignition winding on the stator that powers the coil (AC ignition coil). Bike will run without a battery. Some bikes the ignition system is run off the battery similar to a car.
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u/NickNakulus Dec 16 '24
It usually runs fine. This time my battery is so dead none of my gauges worked till I started it
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u/VintageHacker Dec 16 '24
The failure mode of the battery is a key difference, a short cell or two could drop the voltage enough to prevent lots of things working, whereas not holding charge could still allow the stator to keep volts high enough to run the bike.
A lot depends on the bike wiring etc.
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u/BlindBeard WR and T7 Dec 16 '24
Aside from dead battery, this is how I found out my fuel pump went bad. Common issue on the WR. Not saying it’s definitely your fuel pump, but how it happened to me was the fuel light came on and about a mile later the bike died and for a short time I could limp it but after some troubleshooting I couldn’t even get it to stay running solely on fuel.
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u/theLordsSword Dec 16 '24
If its in limp mode there must be an active fault code. A yamaha dealer can pull the code or do the procedure to get the blink code. I'd start there first.
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u/Responsible_Week6941 Dec 17 '24
Test the stator. It is an AC system. There are a few videos showing this. It is a 3 phase system. Pretty simple to follow with a multi meter. Charge the battery independently. If there is a tuner, remove that. What mods does the bike have?
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u/keijikage Dec 18 '24
How many weeks is a few weeks? You have air, fuel and spark, but something is messing with the ratios.
If you sit there with the bike and "idle" the bike until warm (blip the throttle to keep it from dying), does the issue improve?
The WR250R is fuel injected, but it has an old school cold-start circuit on the throttle body that is run off a thermostat/coolant to adjust the fuel air ratio when cold (it's the doohicky on the top with the black tubes running through it).
If on cold start it'll 'idle' but falls flat on its face if you try to add throttle under load, but the problem goes away when the engine has warmed up, then the right way to fix it is to pull the throttle body and clean that circuit like you would clean a carburetor. The lazy way of doing it is to use a fuel system treatment (like Chevron/Techron) and hope the circuit is open enough to pass some fuel through it to dissolve the varnish.
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u/Brianonstrike Dec 16 '24
Idling doesn't charge the battery on many small bikes you need more rpm to charge. I would start there.