Hey,
I put the original CVK carb back on my bike replacing a poor running mikuni and a week later my battery was dead. Below one volt. I'm wondering if the TPS could have a short to ground, killing the battery. I suspect it because that's the only electrical part that I messed with. Right after I installed the carb the bike started and ran good. The next time I went to ride the battery was dead.
I tried a google search to learn about the TPS but everything is car related. Anybody know how these work and how can I test for a short before I sacrifice another battery.
The bike is a 2007 klx 250 s.

 

Google "throttle position sensor klx250s". Go to the May 6, 2017 entry under this forum heading. Ray Cour probably knows more about the electrical system on our bikes than anyone. Bottom line is it does nothing notable or necessary on our carbed models. Now, as far as a short down stream of the connector, I guess that's a possibility, but a short worthy of draining the battery quickly usually blows a fuse. I don't have my manual handy for the wiring harness pic, but I almost remember even the small owner's manual having a wiring diagram in the back...perhaps?

You will have no issue running the CV carb with it unplugged. You could easily test if the issue is in the carb connection by having a volt meter hooked up with the plug disconnected...then connect it to see if there is a notable drop in voltage as you connect the plug...all with the ignition key on, of course. I doubt much amperage flows through this OEM TPS wiring as it's just supposed to be a signal device for the ignition module.

 

I should have added that the key was in the off position, which may simplify things in tracking down the possible problem.
The battery was a EarthX lithium. I've been in contact with them and they are going to send me a new one as it was still under warranty, only 8 months old. Excellent service answering questions and sending me a replacement. I don't have it yet. Also hoping that they will tell me if it was a part failure or it was my fault.
I'm thinking about buying a cheap battery to test with until I get the new one.
I'll go read the link you sent me, thanks.

 

If it is a low ampere leak, which is sounds like, putting a VOM unit on it and plugging/unplugging is not going to change the voltage enough to determine if that is the problem. IMO. Of course I am a EE.

 

Keep in mind a lithium has less amp hours, so a draw will drain it quicker that it would a lead acid. That said, a real short as the second post said will usually be severe and pop a fuse. A minor draw can be found in a few ways and YouTube can help since the auto and bike process isn't all that different. The first is to meter flow to see where a consumption I happening. Looking for amp draw by first jumping in between the battery and cable then working into individual components. The second is to find voltage on ground where it shouldn't be.

As to ruining the new battery, I'd hook it up, test, and the disconnect it overnight until you find the draw. Look for any aftermarket stuff such as USB ports. The quiescent draw on these can be higher than expected so something that should be minimal is enough to tank a LiPo in a week.

I would think TPS is switched so I'd do all testing key off and look for an amp draw. Also, it seems so many bikes suffer from corroded grounding, I'd make sure that grounds are clean and sufficient, maybe your carb swap just exacerbated a problem that was already developing.

 

Thanks for all the answers.
Got the new battery today. Testing will continue in the next couple of days or so.
Aloeinthehills- the electrical system is stock with no aftermarket stuff hooked up. The turn signals were removed a bunch of years ago, along with the kick stand switch. You say look for amp draw between the battery and cable. Do you mean between the positive battery terminal and the disconnected positive battery cable? I'll check the grounds closer but they looked clean and not corroded. I' ll disconnect them, clean and reconnect.

 

I'm back with more info and questions.
I got the new battery and hooked up the ground to the battery, then put my vom between the positive terminal and the positive cable. With the key off I got 13.2 volts. Pulled the red cap off where the main fuse is and the reading went to 0. plugged it back together and started to disconnect the connections. Got everything unplugged except the regulator and alternator connections. Unplugged the regulator and the volts went to 0. I tested the 3 alternator wires for resistance and to ground. No short to ground and the resistance was .9 ohms. The unplugged regulator has continuity between the two wires. I tested for voltage as I plugged everything back together and only got the 13 volts when I plugged the regulator in.
I guess this means that I have a faulty regulator. It must have failed at the same time as the carb replacement. Do they fail gradually or all at once? Any way to test it to make sure I have the right failed part? They are rather pricy, looks to be around 180 bucks for OEM!

 

I am not sure you have proved a fault. With the meter measuring volts like you had it hooked up it shows there is enough continuity in the regulator to let the meter register.
You might repeat with the meter set to measure current as above post stated. That will show how much draw there is with the ignition switch off. Just don't run the starter with the meter hooked up, it can't take much current.
Keep in mind I don't have KLX anymore so don't have the service manual or wiring diagram.

Brad

 

I agree, that I don't think you have found out anything significantly wrong yet.
I would suggest to fully charge the battery, then test the battery voltage running at various rpms to verify it is charging.
Then let it sit and see if it goes dead.
I don't think you have an electronic throttle sensor. You don't have a usb in the system somewhere?