QUICK GUIDE: How to start a mini quad bike that won’t start

quad bike - kid on a quad bike

Here is a solution to start a mini quad bike or mini ATV that won’t start. Please refer to a mechanic in the first instance. Now when I say mini quad bike or mini ATV generally I mean 49cc quad bikes or ATVs.

To start a mini quad bike:

  1. Turn the key to the ‘on’ position in the ignition
  2. Check that the choke is in the up position and on
  3. Make sure the fuel tap is in the up and downward position
  4. Ensure the plug at the top is on
  5. And try and pull start the quad bike

Quick guide to start a mini quad bike

  • If the quad bike/ATV still won’t start, try to loosen the screw a little bit, at the bottom of the carburetor, and then you need to do a fuel flow test.
  • But when you loosed that bottom screw, make sure the fuel is pouring out of it quickly. Not dripping, but flowing out quickly.
  • If it is not coming out, then you need to check the hose above where the carburetor sits. Because the hose can get squashed and bend too much, not letting fuel pass through.
  • Once you have drained the fuel, put the screw back in, refit it, and make sure it is in the ‘on’ position.
  • The spark plug, needs to be white on the top part.
  • If it is not white at the top, it means you are running too much oil in the fuel mix.
  • Do not over pull the pull start string too much. It should pull out to 1 metre. Do not pull for more length or it will damage the pull start.
  • Make sure the spark plug cap is fitted on top of the carburetor .
  • Once the quad bike is running, the choke must be in the downward position.

Mini Quad Bike Engine Issues
Mini Quad Bike Engine Issues

More detailed guide to start a mini quad bike below…

If you are have trouble starting your bike please try the following:

1) Check your fuel mix

The most common cause of quad bikes or ATVs not starting is due to the incorrect amount of stroke oil. It is either too much or too little 2 stroke oil the fuel or the wrong type of oil.

The oil is added to the petrol for lubrication. Don’t worry, it is not as flammable as the petrol itself. The more oil you use and less flammable the fuel becomes.

25:1 is the best mix whilst running the quad bikes and should be used for the first 2-3 tank fills of fuel, after this the mix can be reduced to 32:1.

Too little or the wrong oil will affect the compression making starting difficult and cause premature ware to the engine.

Use a good quality semi-synthetic 2-stroke oil, if you check the rating on the back of the bottle you fill find the oil’s JASO rating.

You are looking for a minimum spec of JASO FC if you are using an oil with the lower rating of JASO FB this is not good enough please change the fuel oil mix and try again.

Most fully synthetic oils carry a JASO FD rating, this can be used, but is expensive and not necessary, JASO FC is ideal.

Mix the fuel before you put it into the tank, don’t try to mix it in the tank, the oil can sink to the bottom and fill the carburetor, the bike will not start with a carburetor full of 2 stroke oil.


2) Drain the carburetor to refresh fuel

If you have changed the fuel in the tank you will also need to flush the fuel from the carburettor.

To do this tip the bike on it side you will see, at the back of the engine, the carburetor is fitted, in the center of the carburetor float bowl, with is a small Phillips head screw, remove this screw turn the bike upright and turn on the fuel to allow fuel to flow out of it.

If you do not get any fuel flow, please check the fuel tap is on (fuel tap points to the ground in the on position) if the fuel is turned on and no fuel is flowing check for kinks or blockages in the fuel line.

Once you have a flow of fresh fuel into the carburetor refit the drain screw.

3) Choke is not always necessary


On many small 2 stroke engine quad bikes using choke is not always necessary.

Try starting the bike with no choke then half choke then full choke.

Choke lever down is the choke off position.

Choke lever up is the on position.

Also try opening the throttle partly while trying to start.

4) Check for a spark at the spark plug

This will tell you if there is either a fault with a kill switch or ignition coil
Remove spark plug cap and spark plug from the engine.

Place the spark plug back into the cap and rest the spark plug back on the engine so that it makes electrical contact with the threads of the plug and you can see the tip of the plug.

Turn the ignition on and pull the pull start to turn the engine over, you should see a small spark at the tip of the spark plug.

Do not hold the spark plug as you may get a small electrical shock.


If there is no spark at the spark plug tip please check the three ignition cut outs, which are, the ignition switch, the kill switch on the left handlebar and check the safety tether is set correctly.

5) Clearing a flooded engine

If you have been trying to start a bike for some time and it wont start the chances are that you have flooded the engine. A flooded engine is where there is too mush fuel in the engine for it to fire.

To get the excess fuel out of the engine first turn off the fuel and ignition.
Remove the spark plug from the engine leave the ignition off and pull the starter with the throttle fully open a few times, there may be fuel or fuel vapour expelled from the spark plug whole. Continue to do this until no fuel or vapour is being expelled.

Replace the spark plug, do not turn on the fuel and with the choke off try starting again with small amounts of throttle.

When the engine fires up it will soon cut out due to the fuel having been turned off.

Turn the fuel back on and restart.


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