The whole routine, short version:
- Before every ride (5 minutes): chain slack, brakes, tires, throttle snap, loose bolts, gear on the rider.
- After every ride (5 minutes): wipe it down, look for anything bent, cracked or leaking.
- Weekly: clean and lube the chain, check the air filter.
- Monthly: go around every bolt with a wrench, look at the brake pads, put in fresh 25 to 1 fuel.
That is it. These are simple machines. Nothing below takes special tools.
There is no engine oil to change
Worth saying up front, because people come from cars and expect it. The 50cc is a two stroke. There is no oil sump, no dipstick and nothing to drain. Every drop of lubrication the engine gets comes from the two stroke oil mixed into the fuel.
Mix it at 25 to 1, which is 5.12 oz of two stroke oil per gallon of regular unleaded. Oil into the can first, then the gas, then shake it for twenty or thirty seconds. Never run straight gas. The full 25 to 1 mixing chart has the numbers for quarts, half gallons and 5 gallon cans.
Mixed fuel goes stale in about 30 days, so mix what you will actually use. For most families that is a gallon at a time.
The five minute pre-ride check
1. Chain slack
Push up on the chain halfway between the sprockets. You want one to one and a half inches of up and down play. Too tight and it eats the sprockets and the countershaft bearing. Too loose and it jumps off, usually mid corner. If it is off, adjust it at the rear axle adjusters and keep both sides equal so the wheel stays straight. Full walkthrough in our guide to setting dirt bike chain tension.
2. Brakes
Squeeze both levers. They should firm up within the first half of the lever travel and lock the wheel. Spongy, or the lever pulling back to the grip, means air or worn pads. Do not ride it that way. Both brakes on these bikes are discs, so you can eyeball the pad material through the caliper. Under about an eighth of an inch of pad left means replace them.
3. Tires
Set them with a gauge, do not thumb them. Around 15 to 20 PSI is a sensible starting point for a light rider on dirt. Lower gives more grip in soft ground, higher protects the rim on rocks. Check the knobs for cuts and the rim for dents while you are down there.
4. Throttle
Twist it to full and let go. It should snap shut on its own, fast, with no hesitation. If it sticks anywhere, the cable is dirty, kinked or routed badly. Fix it before the bike moves. A stuck throttle on a kid's bike is the worst failure on this list.
5. Bolts and the general look over
Grab the handlebars and try to twist them against the forks. Grab the rear wheel and rock it side to side. Look at the axle nuts, the engine mounts and the sprocket bolts. Vibration loosens things, and a 50cc vibrates plenty.
6. The rider
Helmet, goggles, gloves and over the ankle boots, every ride, no exceptions. Long sleeves and long pants. No gear, no ride, and that rule is easier to hold if it never bends.
After every ride
Wipe the mud off with a damp rag. Mud holds moisture against the frame and it hides the crack or the bent lever you want to find early.
Keep the water pressure low. A pressure washer forces water past the wheel bearing seals and straight into the air filter housing, and both of those cost more to fix than the five minutes you saved.
Weekly, if you are riding most weekends
Clean and lube the chain
Wipe the chain down with a rag to get the grit off. Put chain lube on the inside of the chain run, where it can actually reach the rollers and the pins, then spin the wheel a few times and wipe the excess off the outside. Excess lube on the outer plates just collects dirt.
Takes five minutes. A dry chain on a dusty desert ride can be visibly worn in a single season.
Check the air filter
Pop the cover, pull the filter, hold it up to a light. If it is grey with dust, wash it in warm soapy water, rinse it, squeeze it out (do not wring it, it tears) and let it dry fully before it goes back in. A clogged filter chokes the engine and makes it run rich. A wet filter is worse than a dirty one.
Check the seal around the filter too. Dust getting past the edge of a filter does more engine damage than a dirty filter ever will.
Monthly
- Every bolt, with a wrench. Snug, not gorilla tight. Work around the bike in one direction so you do not skip any.
- Brake pads. Less than an eighth of an inch of pad material left, replace them.
- Spark plug. Pull it and look at it. A light tan or brown insulator is right. Black and sooty means it is running rich or the mix is heavy. White and blistered means lean, and that is the one that hurts engines. Our guide on how to read a spark plug on a two stroke has photos of each.
- Fresh fuel. Anything older than about a month, drain it and mix new.
Seasonal
Before the bike sits for a few months, run the carburetor dry or drain it, drain the tank, clean and lube the chain, put it up on a stand or at least off damp concrete, and cover it. Old fuel turning to varnish in a carburetor is the single most common reason a bike will not start in spring. Step by step in how to store a dirt bike for winter.
Coming back out of storage, mix fresh fuel, check tire pressure, check chain slack, test both brakes and pull the plug before you go anywhere.
Basic tool kit
- Socket set and a couple of open end wrenches
- Flathead and Phillips screwdrivers
- Tire pressure gauge
- Chain lube
- Two stroke oil and a clean, labelled gas can
- Spare spark plug and a plug wrench
- Air filter oil or filter cleaner
- Rags
The tools that came in the crate cover the assembly. The list above covers the rest of the season.
Common questions
How often do I change the oil in a 50cc dirt bike?
You never do. It is a two stroke with no engine oil in the crankcase at all. The oil goes into the fuel at 25 to 1, and that is the whole system.
What fuel mix does a 50cc dirt bike take?
25 to 1. That is 5.12 oz of two stroke oil per gallon of 87 octane unleaded. Ratios you read for other bikes do not apply to this one.
How tight should the chain be?
One to one and a half inches of slack measured halfway between the sprockets, with the bike on the ground. Check it with the rider's weight off the bike and recheck after the first few rides, because new chains stretch.
Why does the bike bog down or foul plugs?
Usually stale fuel, a heavy oil mix or a dirty air filter, in that order. Drain and mix fresh, wash the filter, then look at the plug. If it still will not run right, work through what to check when a 50cc will not start.
How much maintenance time does this actually take?
Five minutes before a ride, five after, fifteen once a week. Do that and these bikes run for years.
Parts
We stock common replacement parts. Text 623 320 8984 with what you need. For the first year, if a part fails we take the claim to the factory on your behalf and get the replacement 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.