Your XJ600 needs two things to start and run fuel/comperssion and spark/electricity. When diagnosing a no-start condition, check and confirm operation as follows:
Confirm that the bike is functioning correctly, electrically, and that it has spark:
- Ensure the engine kill switch is in the on-position.
Ensure the the side-stand is in the up position, that the bike is in neutral, and that the clutch lever is pulled in.
Ensure that the bike will crank over when the starter button is pressed.
Ensure that the clutch safety switch, neutral switch and sidestand switch are all functioning correctly.
Remove a spark plug and ensure the bike produces a spark when cranked.
Confirm that the bike has fuel:
- Ensure that the tank is at least half full of fresh fuel.
Ensure that the petcock is in the on position and that it flows fuel when the engine is cranked.
Open the float-bowl drain on each carburetor and ensure each is filling with fuel.
Pull each spark plug and see if it is wet with fuel.
If the bike has spark and is getting fuel, check the following:
- Verify that the bike has spark on each cylinder.
Verify that the bike is getting fuel at each cylinder.
Raise the tank and ensure that the airbox boots and intake boots are in good shape and tightly connected to the carburetor.
Check the compression in each cylinder and confirm they are within spec.
Typically, a non-starting Seca II will have a dirty carburetor with clogged pilot and enrichment circuits. If your XJ has been sitting for some time and will not start, begin by giving it a full tune up including a carburetor clean and new spark plugs.