Pull the cord slowly. If you feel the engine resist and the cord springs back on its own, the starter is fine and your problem is somewhere else. If the rope is snapped, the handle hangs limp, or it pulls easily without turning anything, the starter is the fault, and which of those three you have decides whether you rebuild it or replace it.
First, make sure it is actually the starter
Most bikes brought to us as broken pull starts are not broken pull starts. They are fuel problems.
The slow pull test takes five seconds. Pull the cord out slowly by hand:
- You feel resistance, then it gets harder, then easier. That is engine compression. The starter is working. Go to what to check when it will not start, because your problem is fuel, filter or plug.
- It pulls out with almost no resistance. The starter is not engaging the engine. Read on.
- It will not pull out at all. Either the recoil is jammed or the engine is seized. Take the starter off and try turning the flywheel by hand to tell which.
- It pulls out and stays out. Recoil spring problem.
The three failures, and what each one means
1. The rope snapped
The most common one, and the only one that is genuinely worth fixing yourself. Rope is cheap. The rest of the assembly is almost certainly fine.
Ropes break at the handle end or where they exit the housing, both from rubbing on a worn edge. If the old rope is frayed rather than cleanly cut, check the exit guide for a sharp lip before you put a new rope through it, or you will be doing this again.
2. The handle pulls out and does not retract
The recoil spring has lost tension, slipped out of its anchor, or unwound inside the housing.
Sometimes it can be rewound. Often the spring has taken a set and will not hold tension again. This is the failure where a lot of people spend an hour and end up buying the assembly anyway.
3. It pulls easily and the engine does not turn
The pawls, the little arms that swing out and grab the engine when you pull, are worn, broken or gummed up. They can sometimes be freed with cleaner and a drop of light oil. If they are chipped, they are done.
Replacing the rope, step by step
Read the safety note first. The recoil spring inside the housing is a coiled steel band under real tension. If it escapes it comes out fast and it has an edge. Wear eye protection and gloves, and keep your face out of the housing while you work.
- Take the starter off the bike. Three bolts. Work on a bench, not on the bike.
- Release what tension is left. If the rope is intact, pull it fully out, hold the pulley so it cannot spin back, and let the rope feed slowly back in while you control it.
- Get the old rope out. Remove the handle, untie or cut the knot, and pull the rope free of the pulley.
- Match the new rope. Same diameter and same length as the old one. Too thick and it will not seat in the pulley groove; too thin and it wears through fast. Measure the old one before you throw it out. Melt the cut ends with a lighter so they do not fray.
- Preload the spring. Turn the pulley in the winding direction, usually three or four full turns, until you feel the spring load up. Hold it there and line the rope hole in the pulley up with the hole in the housing. A clamp or a second pair of hands helps here.
- Feed the rope through. Pulley first, then out through the housing, then the handle. Knot both ends properly and pull the knots down into their seats.
- Let it wind in. Release the pulley slowly and let the rope pull itself in. It should retract fully on its own.
- Test before it goes back on. Pull it ten times on the bench. It should come out smoothly and snap back every time. Do that now rather than after you have bolted it on.
- Bolt it back on. Three bolts, tightened evenly so the housing sits flat. Do not overtighten, the housing is thin.
When to stop and just replace it
Replace the assembly rather than rebuild when any of these are true:
- The housing is cracked
- The recoil spring has come out of the housing, or will not hold tension after rewinding
- The pawls are chipped or broken
- You have rebuilt it once already this season
- You do not want to fight a wound spring, which is a completely reasonable position
Our pull start kit is $29.99 with free shipping and comes with all three mounting bolts, which is the part most sellers leave out. Ten minutes and one wrench.
Making the next one last
- Pull straight, not at an angle. Angled pulls saw the rope against the exit guide. This is the single biggest cause of snapped ropes on a kids bike.
- Do not let go of the handle. Letting it snap back slams the pulley and shortens the spring life. Guide it in.
- Fix the starting problem, not the starter. Ropes break on bikes that take thirty pulls to start. Fresh fuel at 25 to 1, a clean air filter and the right cold start routine mean two or three pulls, and a rope that lasts years.
- Do not let a kid yank it repeatedly on a flooded engine. That is how both the rope and the spring die.
Common questions
Why does my pull start not come back in?
The recoil spring has lost tension or slipped its anchor. Sometimes it rewinds successfully, often it does not. If it will not hold tension after one attempt, replace the assembly.
What size rope does a 50cc pull start use?
Match the old one. Take the broken rope to the store or measure its diameter and length before you buy, because a rope that is even slightly too thick will not seat in the pulley.
My pull start spins but the engine does not turn. Why?
The pawls are not engaging the flywheel. Clean and oil them first. If they are chipped or broken, the assembly needs replacing.
Is a pull start hard to replace?
No. Three bolts and about ten minutes. Replacing the whole assembly is much easier than rebuilding one, because you never have to handle the spring.
Can I convert it to an electric start?
Not on these minis. There is no starter motor mount and no battery or charging system to run one.
Gear, every ride
Helmet, goggles, gloves and over the ankle boots, every ride, at every speed setting. Riders under 18 always with an adult present.
Stuck? Send us a short video of the pull. Text 623 320 8984. If a part came through defective we take the claim to the manufacturer on your behalf and get the correct part sent to you free.
Plugged by 50CC is an independent retailer. We do not manufacture, assemble, modify or service the bikes we sell. Every bike ships sealed in its factory crate exactly as it reaches us, about 90% assembled from the factory, and final assembly and setup are completed by the buyer. Off-road use only. Riders under 18 should always be supervised by an adult.