1 cylinder not firing

Valve job...check. New rings....check. Rebuilt and bench synched carbs...check. So close, my #4 cylinder is not firing. I switched the sparks plugs around, spark plugs are good. I get spark from the #4 wire when I ground it to the motor.When I pull the wire of the plug there is no change in the engine performance. The plug is fouled with unburned gas. Tommorow I am going to check the coils and pick-ups. Anybody have any suggestions? Also my #2 carb leaks gas when I leave the petcock open when not in use....I assume the floats need adjustment(new needles and seats installed)

 

try a fresh plug again. i've seen new ones not last long.

floats shut the fuel off. people around these parts would say install or fuel switch or fix the fuel switch as it doesn't allow fuel to flow when the motor isn't running.

my yamaha sat for 2 weeks with the fuel switch in prime position. and she fired right up when it was time for a ride.

your coils run 2 cylinders. since you only got one cylinder not running. its either the plug or the wire or the carb flooding out or weak compression in the cylinder.

 

I know it's not the spark plug, I swapped the plug from #1 to #4 and #1 still worked with the other plug. Compression is the same in all 4 cylinders. I will check the wire tommorow.

 

you might want to check the resistance in the plug cap, not sure what bike you have but they are usually supposed to be 5k ohm, check the manual to be sure.

cheers,

Trev

 

Hi guys, i need some help! I bought an XJ 600 a couple of weeks ago, its from -95 and it is in good shape (it just passed overhaul before i bought it). A couple of days ago i wanted to start it up after beeing in the garage for 2 weeks, and it didn't start. The owner had told me to put it in prime position, so i did. After a couple of minutes it started. Yesterday when i was goind to take it for a drive with a friend, i noticed that it was weak and that the sound was different..my friend discovered that cylinder 3 was hardly warm.

So, my question; Could it be that i left the prime position on for too long, and that too much fuel went into the cylinder? We were driving the bike for about 30 minutes, and it didn't change, i though that the abundance of fule would somehow vanish and the cylinder would start working..

Thanks alot for your help!!

/David

 

Stompan, welcome to the site. Just a friendly note here, you'd be better off starting a new topic so we can focus on your problem alone. At the same time, Todd that started this thread will get his problems resolved w/ less 'other' stuff to read. this is known as thread hijacking. Also, it'll help us always remember which bike you have if you add it to your signature. -Y

 

Ok, will do, thanks!