Let me guess, you’ve got a go-kart and the pull string snapped when you try to start the engine! Or is it perhaps the fact that the pull start mechanism isn’t working properly anymore? Well, let me tell you that you’re not alone and that this can happen from time to time, especially if you’ve got an older engine or are using a low-quality pull string.
Fixing this is easy, but you’ll need to get a high-quality pull string or new recoil spring. The first option would require you to remove the broken pull string and refit the new one. The second option would be to remove the recoil spring and install a replacement.
Before we start, let me just explain to you how a pull start works on a go-kart engine. This way you’ll find both fixes easier to understand.
When you pull the handle of the pull start it rotates the reel, as a rope is wrapped around it. You’ll also see a ratchet that is attached to the reel. This ratchet is in contact with the crankshaft, and once the reel rotates, it turns the crankshaft, which in turn starts the go-kart engine. This is also called ‘cranking’ the engine.
The recoil spring below the reel, ensures that the reel returns to its original position, so that you can crank the engine again, by pulling the handle continuously. This mechanism can fail from time to time, and in this guide, I’ll teach you how to fix this.
If you’re looking for a guaranteed quick fix, you may want to opt for a recoil starter replacement. This unit comes with all of the required components and offers you a quick solution, instead of having to replace each component individually.
However, if you prefer to identify the issue first and replace only what’s needed, follow the instructions below.
1. Replace the Pull String
It’s common for pull strings on older go-kart engines to snap, due to the wear and tear over time. This can also happen if your engine is equipped with a low-quality pull string. Once the pull string snaps, there is only one way to fix this; you’ll need to replace it with a new string or rope. If the pull string is in good condition, skip this step.
Step 1: Disconnect the Recoil Starter Housing From the Engine
First, take off the recoil starter housing from the engine by removing the 6 screws. After removing the screws, the housing should slide right off.
Step 2: Replace the Old Pull String
Now, you’ll need to replace the old pull string with a new one. I suggest that you use a high quality pull string that has a diameter of around 3 mm (about 0.12”) to 4.5 mm (about 0.18”). You’ll just need to make sure that it fits into the reel hole.
To replace the old string with a new one, you’ll need to remove the reel first, as this gives you better access. Now, remove the two knots, one on the reel and the other on the grip, in order to remove the string.
Take the new pull string and tie a knot on the handle, then push the string through the housing and through the hole in the reel. Take note of the upper red markings on the image above.
The upper circle marks where the rope goes into the reel and the lower circle marks where the knot is tied. You can even tie a small nut or washer to ensure it doesn’t loosen over time. Insert the reel back into position.
Step 3: Reattach the Recoil Starter Housing
If the broken starter cord was the only culprit of the problem, then you can go ahead and reattach the recoil starter housing to the engine. However, if it’s another issue, it’s most likely going to be the recoil spring. In that case, hold off reattaching the recoil starter housing first and proceed to the next step.
2. Fix the Recoil Spring
If your recoil starter doesn’t return to its original position after pulling on the rope, there’s a high chance that the issue lies with the recoil spring. Over time, it may bend or even break. When that happens, you’ll need to replace it with a new one.
Step 1: Remove the Ratchet and Reel
First, remove the ratchet, which holds the reel in place. You can do this by simply removing the bolt that is located on top of the ratchet. If you’ve already replaced the pull string, then you won’t have to remove these components.
Take a matching socket wrench and turn the ratchet bolt counter-clockwise to loosen it. Remove the bolt and the ratchet. This will also give you access to the reel. Remove both components so that you can fix the recoil spring.
Step 2: Fix or Replace the Recoil Spring
The recoil spring is located underneath the wheel and enables the recoil starter to return to its original position after the cord is pulled. Oftentimes, you’ll see it bent or broken, especially on older go-kart engines.
You can simply replace it with a new durable recoil spring. Simply take the old one out, and place the new one in position. Take note to always check the measurements of the new pull string beforehand.
If you’re unsure, then I would recommend that you get a recoil starter replacement unit that fits your engine instead (also check dimensions, here).
Step 3: Reassemble Reel and Ratchet
Now, you can simply reinstall the reel with the new recoil spring onto the housing. After that, place the ratchet and its bolt back in place and tighten it using a socket wrench.
Test the recoil mechanism thoroughly before installing the recoil starter housing and its components back to the engine. Ensure that the recoil tension is optimal and that it’s allowing the recoil starter to return to its original position after every pull.