Troubleshooting Small Engine Electric Start Issues

Welcome back to the RuggedMade Tech corner. I'm Jared, and I'm Nick. Nick is the head technician in our customer support department. He really knows his way around the lawn and garden engines that you'll find on equipment like our RuggedMade log splitters, plate compactors, generators, chippers, and machines like that.

We are continuing our series on maintaining, troubleshooting, and repairing these small engines. In this episode, we are going to take a closer look at the electric start system. So, getting to this point assumes you've already performed all the required routine maintenance and the engine on your machine can be started with the pull start and it runs normally. If you haven't watched it already, be sure to check out our main troubleshooting video by clicking the link here or in the description.

Today, we're focusing on the Raven R420 and the Honda GX390 engine. These are both popular engine options on RuggedMade log splitters. The Raven is a perfect example of a clone of this Honda GX line of commercial engines. You might be familiar with some other well-known examples like the Harbor Freight Predator, engines from Loncin, Lifan, Duramax, and Champion.

The electric start panel, starter solenoid, starter motor, and wiring vary from model to model. Engines from Honda, Briggs, Kohler are all a little bit different. However, the same techniques generally apply. Refer to your engine's owner manual for more details.

Before we look at the electric starting system, does the engine start with the pull starter? If so, that means the issue is limited to the electric start system. If you can't get your engine started even when using the pull starter, well, there's an issue somewhere else, such as bad fuel, clogged carb, low oil, ignition, etc. So, you need to figure out why it won't start with a pull starter and why it won't run properly before you worry about the electric start. It's really an extra system. So, go back and watch our main troubleshooting video.

If you're working on a machine that has a hydraulic system and has hydraulic valves, you need to make sure that the valves are in the neutral position like these. And you want to make sure that none of them are in a position like that. This is a log splitter. This is the return detent position. And if you happen to leave the valve in this position, like maybe it ran out of gas while you were retracting the rod, that can happen. This is what could happen when you go try to start it.

So, that sound can mean a few different things. It sounds like the motor could be locked up or the battery could be weak. Yeah, and if you don't have a little hydraulic system or you've checked all your levers are in neutral, then that would be the next thing to check. But it could very well just be that your hydraulic system is locked up. Because if that lever is not in neutral, it's preventing any hydraulic fluid from moving, and it's locking up the pump. And you're basically asking the electric start motor to turn the hydraulic pump. That’s not what it’s designed for. So, it just is going to slow down like that. Now, when everything's in neutral, this is what it should sound like.

What do you do when your electric start system isn't working? What are some of the symptoms that would indicate a problem with your electric start system? And we're talking about what happens when you turn that key to the start position. So, one symptom could be, nothing happens. You can hear a click. That would be the starter solenoid clicking. It could be that you hear that click and the starter motor tries to turn the engine over but much too slowly to start. You can also blow a fuse or trip a circuit breaker. The Raven has a resettable circuit breaker, and with the Hondas, some of them just have an internal fuse. This one happens to have both a circuit breaker and a fuse.

The first thing to check is that the battery is hooked up correctly. Believe it or not, it happens pretty often. Maybe you brought that battery in over the winter to charge it or you replaced your battery and it gets hooked up backwards.

The positive side of the battery is represented by a plus (+), which gets the red wire. The negative is the minus sign (-) and that is your ground. When hooking it up to the small engine, red goes to your starter solenoid and ground is going to your block.

Most engines equipped with electric start will have a start panel like this. It’s just an ignition switch with an off, run, and a spring-loaded start position, just like a car. If you turn the key from start to run and nothing happens, you want to check the circuit breaker or fuse. The Raven has a circuit breaker built into the starter panel.

So here we can simulate what an overload situation would do to the circuit breaker. We’re going to go to the start position, and it might be hard to hear, but we could hear that circuit breaker trip and there's a little colored plunger in there. On this one it's red. On the Honda, it’s green. And that's going to pop out in this little window and that's going to indicate that there was some sort of overload. The Honda GX390 also has a fuse in the starter panel as well as a circuit breaker. So, you want to open up that panel, check that fuse, and if it’s burned, replace it with the same amperage fuse that you’re taking out.

Once you have replaced the bad fuse or reset your circuit breaker, try to use the electric start again. If the breaker trips again or you burn another fuse, there’s probably a short in the system, a bad ground, reverse polarity on the battery, or something like that. But if it doesn’t re-trip, then you can move onto the next step in the troubleshooting process.

If it does trip again, start by inspecting the starter panel box by cleaning the ground and inspecting all solder joints and making sure everything is connected. Yeah, sometimes you might find bug nests in here or from a long life of vibration, these little solder joints can fail. Corrosion can creep in. So, it’s just a good opportunity to check for the health of your wiring.

The number one problem we see with electric start systems is weak or bad, dead batteries. We’re going to test the voltage in your battery to make sure it’s good. If you don’t already own a multimeter, now is the time to invest in one. These are really affordable and you can get these at any auto parts store or hardware store. Once you have [a multimeter], you’re going to find you’re going to be using it all the time for diagnosing things like this on a small engine or a lawn tractor, or your jet ski or your car. They’re just really handy. I like using this, which is an integrated test light with a voltmeter. It just saves me a lot of time when I’m doing this kind of troubleshooting.

Check the battery voltage. Do this when the battery is in a resting state. This means the battery has been sitting for a few hours since being fully charged. If you check the voltage too soon coming from the charger, you’ll get an inaccurate reading. This is a good battery that I know and it has 13 volts in it resting. A fully charged, healthy battery should have a resting voltage of approximately 12.6 volts. Anything less than that could indicate that it’s just under-charged or that it’s unhealthy and needs to be replaced.

On this battery with my little meter here, I’m only getting 12.3 to 12.4 volts, so it could just be that it needs to be charged or could be bad. The first thing I’m going to do is put it on a charger.

Here we have an example of one of those smart chargers. This Optimate, if I hooked it up and left it on there, it would do a whole desulfate mode, balance the cells, and hopefully get me a full charge or it would tell me this battery is not capable of holding a whole charge. Keep in mind that even for a smaller battery like this, a full charge can take upwards of four to six, almost eight hours.

If the battery can’t hold a full charge, it really does need to be replaced. If your battery charger says your battery is fully charged but it still doesn’t have the cranking power that it needs, it might be worn out. Auto parts stores can test your battery for free or there’s some at-home diagnostic tools like this voltage meter that you can use to test a battery.

This is an old school resistance load tester. It does a really good job of telling you the health of the battery. It's just like hooking it up to a whole bunch of incandescent light bulbs.

So in this case, it goes right into … it stays in the good zone, which makes sense because this is a battery that we know is new and fully charged at 13 volts. But now, let's try it on this other battery where I was only getting 12.4 volts before. It could just be low on charge, or it could just be a weak battery that needs to be replaced. Yeah. And, it goes right into the bad zone, and that pretty much indicates that it's dead and needs to be replaced. We could try putting it on the charger for a few hours, and we may do that. But what if you don't have enough time to go buy a new battery or charge up your battery?

There are a couple ways you can speed up the process. Again, we're just trying to diagnose what's wrong with our electric start system. One way to do that is with a boost pack like these guys. Another way to do it would be to hook it up, jump it with an external battery. We don't really recommend using a big car battery, but if you are going to jump it like that, we recommend not having the car running. You don't want that powerful automotive alternator cooking the rather light-duty system on these small engines. And whether using a jump pack or an external battery, make sure you get that polarity hooked up correctly.

And so now, try your electric start. Whether you're using a boost pack like this or an external battery, or you fully charge your battery. And if it works well, you've pretty much answered the question of what was wrong with your system. It was the battery. So either fully charge that battery or replace it. All batteries self-discharge. As the battery sits there, it loses a little bit of power hour every day, every week, every month. If it sits for a while, the battery's going to be dead, and it won't start your equipment. You want to leave it on a battery tender with the float mode. That can keep the battery fully charged and keep it healthy. If you live in a cold climate, the cold can also hurt the battery. You want to bring it inside, keep it warm and dry.

Before you start testing and replacing more parts like the starter solenoid and the starter motor, make sure that the wiring on your motor is in good condition.

Now, the wiring can be different from engine to engine, not just between different makes but even different models from the same manufacturer. So we're not going to get into the details of exactly what the wiring is like on every engine, but they mostly follow the same pattern. You're going to have power going from your battery to the back of the starter solenoid, into your start panel, and from there to the starter motor. So it's all pretty consistent.

When you're checking the wires, you want to look for rusted and loose connections. And also, sometimes these bullet connectors can pull apart, be loose, or have corrosion inside. And on the back of the starter solenoids, sometimes the two small wires that are part of the energizing circuit disappear inside the body. Like on this one, they're molded in. Sometimes, like on this one, they're a spade connector and a ring terminal, and those can also become corroded or loose. So check those.

Otherwise, to keep an eye on … otherwise from your battery, so you have your ground wire leading to your engine and also the power wire going to the starter solenoid. Make sure those aren't loose, frayed, or rusted. And when you check those ring terminals and at the battery post, if they're rusted or corroded, you want to clean those. The best way to clean those is with a brass wire brush or a piece of sandpaper. So get those nice and clean so you have a good ground. And also, avoid having any ground connections that go through a painted or powder-coated part of the engine. For example, you wouldn't want to ground to the bolt here that goes through the pull start shroud.

If your battery is healthy and your circuit breaker and fuses are all good, and the connections are all tight and clean, it's time to start looking at the starter solenoid. The starter solenoid is also called a relay.

So, to check the solenoid, we're going to jump it or bypass it. Where's that screwdriver? We've got these two posts here that connect the positive terminal of the battery to the positive terminal on the starter motor, going through the relay. And we're going to use a rubber-handled screwdriver so we don't shock ourselves, and we're just going to touch those two posts.

You'll probably need to remove that little rubber boot on the terminal that has the wire going to the starter motor. Jumping the solenoid can be a little bit dangerous because there's going to be a spark, which could ignite fuel or fumes, in particular. So you want to make sure the fuel cap on the engine is closed, and there are no flammable materials around. And really, you want to do this outside.

As you momentarily jump the posts, the starter is going to spin, and hopefully, the engine turns over. And that pretty much means that your solenoid has failed. Not necessarily, so we can still test the solenoid a little bit further. You don't have to remove the solenoid for this test; you would just need to disconnect the two wires for the energizing circuit and the two big wires from the starter motor and the battery. But what we're looking for is to see if that solenoid clicks.

So we'll hook it up to a battery here. So it does click, but that's not a complete test. So let's go one step further and make sure that when that circuit is energized, we are getting continuity across the two posts. So that is a perfectly good solenoid.

If the solenoid is good, you may have a bad ignition switch. We'll come back to this and test the ignition switch later. If the solenoid clicks but the starter still does not turn, you can still have another issue past the solenoid, between the ground and the engine block, or the solenoid power wire to the starter itself.

These solenoids are inexpensive and readily available. They're also easy to install. They mount to the body of the starter motor with just two bolts. Note the location of all the wires before disconnecting any of them. Taking some pictures before disassembling can help with the installation process. After the new solenoid is bolted on, connect the wires.

The solenoids usually have four wires. A heavy-gauge power wire, usually red, goes from the positive terminal on the battery to one of the large posts on the back of the solenoid. A second heavy-gauge power wire connects to the other large post on the back of the solenoid, and it goes to the terminal on the side of the starter motor. And then there are one or two thin gauge wires for the control or energizing circuit from the ignition switch or the start button. These may connect to a post or spade on the back of the terminal. In this case, there's a spade. And there's also one other thin gauge wire that may have a ring terminal on the end, like this one, and that's connected to one of the posts as well. Sometimes, the two thin wires are molded into the body of the solenoid, and they connect internally, like on this one.

Try starting the engine. [Engine starts]

So that new solenoid works. If the starter solenoid works correctly, we can move on to the starter motor. The starter motor usually only has one terminal, and this is for the positive wire coming from one of the posts on the starter solenoid. It's usually the one protected by a rubber boot, and the motor grounds to the engine block through its body.

You can test the starter motor while it is on the engine using wires that are at least the same gauge as the wires that connect to the battery. Connect the negative terminal to the engine block or the body of the starter itself. Connect the positive terminal of the battery to the terminal on the starter motor. There's a risk of shock and spark when doing this. If the motor spins and the engine turns over, then the starter motor is okay. If it doesn't spin, you'll need to remove it and replace it.

The starter motor is mounted to the engine with two bolts, shown here. We've already removed the pull-start shroud on this 212 cc Raven engine. As you can see, the heads of the bolts are located behind the flywheel. So replacing the motor is a more involved process that requires removal of the pull start, the ignition coil, the flywheel, and so on. We're not going to cover that here. We'll cover that in a future video.

The starter motors on these engines are quite robust and can last a long time. Double-check all the other parts of the electric start system before replacing the starter motor.

If the solenoid worked when you bypassed the ignition switch and introduced power directly to it, and if the starter motor works, you could have a bad ignition switch. So let's do a simple test on a typical switch. This is basically a continuity test. Use the ohms or continuity settings on your multimeter. A dedicated continuity tester like this one Jared has is helpful for troubleshooting electrical systems.

Find the wire that goes to the energizing circuit on the solenoid and the ground. Check for continuity across this circuit when the key is in the start position. [Multimeter beeping] So you can hear that sound coming from the multimeter. And then we can also do it with this dedicated resistance meter. So if there is no continuity, the switch is probably bad.

Again, we're assuming that the off and the run positions do allow the engine to run and be shut off when using the pull starter. If either or both of those positions aren't working, well, there are some other issues such as a short to ground or a bad ignition coil, and that's going to require some different troubleshooting.

Hopefully, you were able to identify the issue, and your electric start system is working now. We all know these engines don't really need electric start, but once you get used to the convenience of it, it’s hard to go back to just using the pull start. Not to beat it to death, but most electric start problems are caused by dead batteries and bad grounds.

Well, thanks for watching. Be sure to check back here for more videos and let us know in the comments what other topics you’d like us to cover.