My XJ fills with fuel and then won't start. What's wrong?

[radare]

My XJ keeps filling up with fuel and then won't start. What's wrong?

If your Seca II is flooding and failing to start, you need to diagnose the problem and repair it immediately.

The amount of fuel in the carburetor is controlled by the float and float valve. If the float valve fails, excess fuel can be pushed through the carburetor and into the engine. When this happens, the cylinder will fill up with fuel and the engine may hydro-lock. Attempting to start a hydro-locked bike WILL damage your starter gear or bend a connecting rod (or both). If you try to start your Seca II and you notice it's flooded, remove the spark plugs and roll the engine over; this will push the excess fuel out the spark plug hole and prevent damage to the starter gear. Never attempt to start a hydro-locked bike without clearing the cylinders first.

If you have problems with flooding, check the following for problems and correct:

The most common cause of a flooding bike is a petcock which has failed and flows fuel when the engine is off. With your engine off and the bike cool, place a rag under the fuel line at the petcock. Ensure the petcock is in the "ON" position. Remove the fuel line. If fuel leaks out of the petcock, it's vacuum diaphragm has failed and it should be rebuilt or replaced.

The second most common cause of flooding is from dirty, sticking or worn-out float needle valves. Remove the carburetor assembly, remove the float bowl, remove the floats and check the condition of the needle valve and needle valve seat o-ring. If either is worn, replace all of them on all four carbs.

The least common cause of flooding is from improperly set float heights. If the float heights are set too low, fuel will fill up the carburetor and can leak into the engine. Remove the carburetor assembly, remove the float bowls and set the float heights to spec (6.2 to 8.2mm).

Again, NEVER try to start a flooded or hydro-locked bike! This can't be stressed enough.