It’s common knowledge that engines use batteries. That applies to an engine for a truck, car, or boat. But how about the pull-start engines that generators or lawnmowers use?
Does a pull start engine need a battery?
No, pull-start engines do not need a battery. They get the necessary power to start the engine when the cord is pulled. The cord is attached to the crankshaft. When the cord is pulled, it rotates the shaft, engaging the flywheel. The flywheel then rotates the pistons, eventually starting the engine.
That answers your question, but that’s only surface-level stuff. Allow us to explain why a pull start engine doesn’t need batteries and how they work.
Everything will be revealed as you keep going through the article.
Does A Pull Start Engine Need A Battery?
The purpose of a battery in a car or another engine is to supply electricity for it to start. But pull start engines do not need batteries because they get their energy from another source.
That energy is generated by the force of pulling the cord.
The cord also called the starter, is the key here. The starter is combined with a rope and a handle at the end. The other end of the rope is connected to the crankshaft.
When you pull the handle, it causes the rope to spin the crankshaft. The spinning of the crankshaft cranks the engine and engages the flywheel. The flywheel then works the pistons, which generate enough power to start the engine.
There are three different types of pull start engines: recoil start, old-fashioned rope start, and easy start. All of these use the same principle and do not need a battery.
The starter rope comes out of the engine when you pull it. If the engine fails to start, you’ll need to reattach the rope and pull again.
On modern easy-start engines, there is a decompression valve. This feature reduces the compression needed for the engine to start. You can start these engines with fewer pulls and less effort.
These pull start engines are normally used in lawnmowers, chainsaws, and small outboard motors. Also, some motorcycles can run without a battery.
How Does A Pull Start Engine Work Without A Battery Power?
Let us walk you through what a battery does for a car’s engine.
The battery provides power to your car’s engine. When you push the start button or put the key in the ignition, it sends a signal to the solenoid. The solenoid then closes a pair of metallic contacts.
When that occurs, the battery supplies the starter motor with enough voltage to start the vehicle.
So, that’s how a battery, with the help of a solenoid, starts a push engine. Besides a battery, solenoids also play a vital role in starting your car. In fact, a bad solenoid can drain your battery.
Now, let’s come back to our good, old pull start engine. It has no problem working without a battery, as the power needed to start it comes from the pull. That pull rotates the crankshaft, which activates the flywheel, eventually starting the engine.
Source: Popular Mechanics
Should You Convert A Pull Start Engine To An Electric Start?
Pull-start engines are not very practical nowadays. Come on, would you like to start your lawn mower with the press of a button or by pulling a rope with all your strength?
Electric start engines are much easier to start than pull start engines. The more CC or HP an engine has, the more energy it needs to start, which means you literally have to pull the rope with all your might.
Even that doesn’t guarantee that the engine will start in one pull. No matter how strong or habituated you are to starting a pull engine, you might need a couple of tries to get it going.
Things get even harder when someone too old or too young has to do a pull start. That would be physically impossible for them.
But the thing is, you can convert your pull start engine to an electric start by yourself very easily. Check out the next section; we have a step-by-step guide on how to convert a pull start engine to an electric start engine.
Steps To Convert Pull Start Engine To An Electric Start
You can definitely convert a pull start engine to an electric start. But there is one thing to keep in mind.
The whole process depends on the engine you are using. Some manufacturers, like Honda, Kohler, and Briggs & Stratton, designed their engines to be convertible. That is not the case with all the manufacturers.
So, before you want to convert, check if your engine is compatible with a change.
To check the compatibility of a change, you must check the engine’s manual. If you’re lucky, the manual will have a complete description of how to do it.
Can’t find it in the manual? Well, there is another way to check.
There must be some mounting holes, an access plate to the flywheel in the engine, and a ring gear on the flywheel. Without these, conversion isn’t possible. The mounting bosses are needed to mount the starter, so this is a must.
But if your flywheel doesn’t have ring gear, you have to get another one that does.
Assuming you have everything you need, we will now move on to the process of conversion.
What You Will Need
- Starter Motor with Solenoid,
- FlyWheel with Ring Gear,
- Key Switch Box with Keys,
- Charging Coil,
- Mounting Bolts,
- Fan cover shroud.
These are the simple steps that will convert your pull start into an electric start. Make sure you follow the instructions word-for-word.
- Disconnect the fuel wire from the fuel filter. Use a bowl to collect if there is any residual fuel left in the wire.
- Remove the access plate to get into the flywheel. If your flywheel has ring gear, you can keep it. Otherwise, you have to remove it and install one that does.
- To remove the flywheel, detach everything it is connected to. Then unscrew its bolts with a wrench.
- When you connect the new flywheel, do the same thing but in reverse order.
- Now, you will need a starter motor, which should come with the kit. There are both 12v and 110v starter motors. For snowblowers or lawnmowers, get the 110v starter. For generators, a 12v motor is preferable.
- The rest of the steps are easy. Mount the starter motor on the engine and connect it to the battery.
- Then mount the solenoid and the switch. Connect the switch to the solenoid and the solenoid to the starter motor.
- Make sure to ground the negative battery cable.
That’s everything you need to do to convert a pull-start engine to an electric start engine.
If the instructions are not clear enough for you, you can watch this video: How To Convert a Pull Start Generator to Electric Start
Or, you can get some expert help.
Safety Measures to Take
The conversion from a pull start to an electric start is not that complicated but still sensitive. Also, since you are handling electricity, you must maintain the safety protocol.
If you are not sure what you are doing, get help from experts. Working on a sensitive issue while being confused might lead to an accident.
Make sure to always use goggles, hand gloves, and a boot. Never touch a live open wire while working, and do not work barefoot. The price of getting electrocuted is higher than you imagine.
Can a pull start outboard charge a battery?
Yes, a pull start outboard motor can charge a battery even though it does not have an electric starter. But you must modify your outboard motor to some extent to achieve that feat.
Do pull start outboards have an alternator?
No, they do not have any alternators, as they do not have batteries. Alternators are only needed to charge batteries, so if your outboard motor doesn’t have one, it also won’t have an alternator. But if your outboard motor has an electric start feature, then it will have a battery and an alternator.
Why is it hard to pull cord on lawnmower?
There are quite a few reasons why your lawn mower pull cord is giving you a hard time. These issues include spilling oil in the exhaust, too much water in the cylinder, or a faulty crankshaft.
Can spark plugs work without battery?
Yes, even without a battery, spark plugs can work. There are basically two ways spark plugs can get energy. One is from the battery, and the other is from the magneto. It uses the magnetic principle to generate the required energy.
So, does a pull start engine need a battery? No, it does not. It can easily do its job without one. But that makes your job hard because starting a pull start engine is quite troublesome.
But it is possible to convert your pull start engine into an electric start. The process is probably easier than starting a pull start engine.