Fuel on scooter spark plug / wet spark plug , Petrol/gasoline on spark plug. Reasons, symptoms, troubleshoot & repair.
Fuel on scooter spark plug / wet spark plug , Petrol/gasoline on spark plug,scooter stalling/bogging when accelerating – Reasons, symptoms, troubleshoot & repair.
Before starting following step by step guide, please make sure engine oil is in correct level & good condition.
Engine oil, spark plug & carburetor.
Before jumping on to conclusions like – may be engine gasket is leaking or piston ring is worn out or low compression or other major issue is there, please make sure to make to solve any problems in 4 main things for smooth working of engine. Spark plug, Engine oil, carburetor(air fuel ratio) & vacuum.
- Make sure there is no air leak or vacuum leak.
- Change all rubber tubes(fuel line, vacuum) if they are old.
- Tap carburetor with a small hammer( believe me sometimes this works 🙂 it is a temporary fix though).
- Make sure fuel tank tap vent(micro vents) is not blocked.
Faulty spark plug itself may be the reason for fuel on spark plug. If you already changed spark plug – and it ran it for some time or it stops after engine getting hot or after few days. Then remove and check spark plug again. If it is still wet with fuel please follow following step by step procedure. If you already did change air filter, cleaned & and tuned carburetor & replaced spark plug then skip to step 5.
Step 1 – Clean or change air filter
One of the main reasons for too rich fuel mixture is air filter. Air filter should be replaced or cleaned in regular intervals. So as a first step replace air filter.
If it is really dirty and stops the flow of air it maybe the reason for too rich mixture. But it is just the first step & main reason may not be this. So proceed to next step.
Step 2 – Clean everything inside carburetor
Watch a video of the particular vehicle carburetor to make sure you are not messing up anything. Replace everything back.
There are few small holes and jets inside carburetor. Remove carburetor from vehicle and open it. Clean everything including pilot jet and main jet. As of now, don’t mess with tuning screw & spring. If you find something is clogged, that might be the reason for all mishaps.
Float & float pin – float along with pin plays a very important part in making sure that fuel air mixture is perfect. If float is too low or high it will lead to either lean or rich air fuel mixture. Float going too low may be the reason for fuel on spark plug. plastic floats can’t be adjusted, so if you are sure that float is faulty change it along with the float pin(float pin is a very small needle with a very small hard rubber like tip that stops flow of petrol to carburetor). Or replace the carburetor as a whole.
Step 3 – Make sure no vacuum leak.
As mentioned above, removing all old tubes(those which lost elasticity) and replacing with new is a good idea. Vacuum leak is one of the most tricky things. Because it will cause same symptoms like a faulty electrical system. So make sure that there is no vacuum leak before buying parts.
Step 4 – Tune carburetor.
Out of tune carburetor can be a reason for fuel on spark plug, scooter bogging when accelerating, stopping after running for few miles etc. There is many youtube videos on how to tune carburetor of almost every single scooter/bike model. If you are not confident enough to do it approach only experienced mechanic.
Step 4 – Replace spark plug.
Replace spark plug and check its condition. If it is still wet with fuel go to step 5.
Step 5 – Set float level & replace float pin.
After completing above 4 steps for a small ride – stalling when accelerating scooter ? loss of power when accelerating after few miles? engine misfires ? If you are still seeing this problems
Step 6 – Replace Ignition coil ?
If ignition coil is faulty, you may face other issues along with above mentioned problems. For example irregular idling, engine misfire etc. But before replacing it make sure all 5 steps are completed.
Step 7 – Replace CDI Unit ?
Sometimes it is very difficult to find the real problem with a motor scooter/bike. CDI unit usually either works or it just stops. But sometimes it will stop working after running for few kilometer. Scooter just stops and will start only after few minutes.