why does dirt bike spark plug flood out?

JasonLW

New member
You need to adjust your carb, your bike running to rich. look at your owners manual and adjust fuel to air ratio. There are some screws on the carb you can turn to adjust this.

You can also adjust the jets, by raising or lowering the jet in the carb. look up some info on adjusting the jet before you attempt it. I think raising the jet causes it to run richer.
 

DavidS

Member
I have a 70cc 4-stroke chinese dirt bike and after I ride it, it wont start up unless I take out the spark plug and wipe it off.
Once you wipe it off and start it up, it runs fine until I turn it off again. When I pull the plug out it has a gas/oil mixture on the tip. Does anyone know what causing this?
 

scivi92

New member
I don't have very much detail to offer but I would say that there is a valve seal which keeps oil from leaking down into the combustion chamber (where the plug is) and this seal most likely needs to be replaced.
 

scivi92

New member
I don't have very much detail to offer but I would say that there is a valve seal which keeps oil from leaking down into the combustion chamber (where the plug is) and this seal most likely needs to be replaced.
 

MadJack

Member
You mention a gas / oil mixture on the spark plug tip. You also say this is a 4 stroke engine. A 4 stroke engine should not have any oil mixed with the gas. Are you using 2 stroke gas in a 4 stroke engine? If you have gas mixed with 2 stroke oil in your tank this will give problems. Drain the 2 stroke gas and put gas only in the tank.

The carburetor is incorrectly adjusted.

If either of these fail try the next hotter heat range spark plug.
 
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