Our resident powersports expert John Talley goes live every Friday at 3pm Eastern on our YouTube channel, and in this session, John answers some of our viewers' questions about motorcycle and ATV electrical system repairs.
Motorcycle-ATV Electrical Repair Questions & Answers
My 125 4-stroke dirt bike skips a spark when warmed up like every 5 minutes. It's like it just almost dies, but then keeps going. Why is that?
John Talley: That can be a variety of things, a huge range. I’ve even seen a bad ground connection on the battery coils with what you’re describing right here, but it is definitely an intermittent problem. Somewhere on the ignition and/or electrical system. Start simple. Go ahead and check your grounds on your battery. Make sure that there’s no corrosion in there. After that, check the connection on your ECU and then whatever type of CDI, whether it be built into the ECU or separate, that’s actually sending the spark to the spark plug. It’s going to be a process of elimination. It always is with electrical, but always start with the simplest stuff.
Watch the video above to see how to change the battery in a Kawasaki dirt bike.
I put my battery in backwards and my fuses melted and started smoking. What do I do?
John Talley: Unfortunately, you’re going to need to replace your wiring harness. And hopefully you didn’t damage anything beyond that as far as the ECU and the different devices it was connected to. I would not try to straighten out a harness that suffered that kind of trauma. You may think you’ve gotten all the wires replaced that you need to, but when it actually gets connected backwards and all those wires heat up when they’re not supposed to, they start burning into each other or melting into each other and making connections and it just creates a nightmare. I’m sorry you’re having to go through this, but now is the time to just strip the machine down to where you can get to the wiring harness and get it replaced.
Watch the video above for tips on wiring harness repair do's and don'ts.
How do I wire up a tether kill switch on a Honda Rancher?
John Talley: Well it should be one of two ways, depending on the type of machine, in this case a Honda Rancher. So that’s going to be a complete circuit I believe, where on some special motocross bikes, they run a single wire up there, you hit the kill switch and then it just grounds it out. So there should only be two wires for you to tap into, depending on what type of killswitch you’re hooking up. There shouldn’t be any polarity because you’re basically just making a connection that’s going to kill the machine. That should be just two wires, more than likely. On the Honda Rancher it’s going to be.
Watch the video above to learn how to troubleshoot starting problems on a Honda ATV.
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