EX500 running on one cylinder?

fret8 · 08-06-2005

Hey I have an 89 ex500 and all of a sudden it just started running on one cylinder, which sounds very loud out of one of the pipes and is hard to keep running. I have had the problem with the carbs leaking so I know what it is like flooding the spark plug. However, the spark plugs are clean, the carbs work well, and I am feeling a little warmth from the "so called" inoperative cylinder. The carb bowls fill up and I'm pretty sure there is gas going into the cylinder, however it is still running rough and very loud and a lot hotter from the good cylinder. I guess I'm asking if anyone has any clue or hints on what it could be. I was thinking maybe about the mixture ratio maybe lack of air? Or timing? I was riding it, then two hours later I tried to fire it up and it went right to one cylinder. THanks in advance for the help guys!

-colin

Redline · 08-06-2005

Stuck float in the carb or something like that. Try tapping the side of the carb on the side in question with a rubber hammer, or a block of wood and a regular hammer. How long have you had the bike, were there any mods on it?

fret8 · 08-06-2005

no mods, but the floats don't seem to be sticking, I've taken it apart a couple of times. Are you just saying that the mixture is too rich, yet it is still firing?

Redline · 08-06-2005

Might want to test the spark plug and wire on the appropriate side, make sure it's still firing. It's possible to have one coil go bad on those. And make sure the plug didn't back itself out of the cylinder, I had one do that to me on the highway once. Wouldn't run without a lot of throttle input. Lots of dumb little things can make these bikes start running on one cylinder. Also try closing down the pilot jet on that side, might have vibrated open and it's flooding a bit. The jet adjusters have caps on them from the factory, if yours does not then it's a good bet the bike has a jet kit. The adjusters are right over the top of the starter and in the vertical plane. The screws that stick out the sides are the float bowl drains....

fret8 · 08-07-2005

spark plug give good spark, but I'm now thinking that I'm really not getting any gas into the cyclinder, any hints on how to double check this? I know i have gas in the bowls.

Thanks

zx10tod · 08-07-2005

You could pull the airbox and shoot a LITTLE starting fluid in the dead carb with the enging running. See if it fires.

I had a 500 and always had trouble with the carbs plugging up. Finally did the liquid tank liner and installed an inline fuel filter. Didn't have trouble after that.

fret8 · 08-12-2005

problem fixed...bad spark plugs

fret8 · 08-12-2005

I put new plugs in but it seems to backfire just a little more then normal...could that be because of the plug gaps?

Redline · 08-13-2005

EX500s have that problem. It's due to some emissions equipment on top of the engine. If it's backfiring, that actually means it's finally running right. If the backfiring really bothers you, I can tell you how to eliminate that emissions stuff.

08-06-2005	#1 (permalink)
fret8 Newbie Join Date: Aug 2005 Posts: 5	EX500 running on one cylinder? Hey I have an 89 ex500 and all of a sudden it just started running on one cylinder, which sounds very loud out of one of the pipes and is hard to keep running. I have had the problem with the carbs leaking so I know what it is like flooding the spark plug. However, the spark plugs are clean, the carbs work well, and I am feeling a little warmth from the "so called" inoperative cylinder. The carb bowls fill up and I'm pretty sure there is gas going into the cylinder, however it is still running rough and very loud and a lot hotter from the good cylinder. I guess I'm asking if anyone has any clue or hints on what it could be. I was thinking maybe about the mixture ratio maybe lack of air? Or timing? I was riding it, then two hours later I tried to fire it up and it went right to one cylinder. THanks in advance for the help guys! -colin

08-07-2005	#6 (permalink)
zx10tod Sit speling cheker BTK Expert Join Date: Mar 2005 Location: Idaho Posts: 435	You could pull the airbox and shoot a LITTLE starting fluid in the dead carb with the enging running. See if it fires. I had a 500 and always had trouble with the carbs plugging up. Finally did the liquid tank liner and installed an inline fuel filter. Didn't have trouble after that. __________________ 1988 ZX10, Vance & Hines SS2R exhaust, stage 3 jet kit, K&N filters. Like I needed another project!

08-06-2005	#2 (permalink)
Redline Banned BTK Expert Join Date: Mar 2005 Location: Denver Colorado Posts: 459	Stuck float in the carb or something like that. Try tapping the side of the carb on the side in question with a rubber hammer, or a block of wood and a regular hammer. How long have you had the bike, were there any mods on it?

08-06-2005	#3 (permalink)
fret8 Newbie Join Date: Aug 2005 Posts: 5	no mods, but the floats don't seem to be sticking, I've taken it apart a couple of times. Are you just saying that the mixture is too rich, yet it is still firing?

08-06-2005	#4 (permalink)
Redline Banned BTK Expert Join Date: Mar 2005 Location: Denver Colorado Posts: 459	Might want to test the spark plug and wire on the appropriate side, make sure it's still firing. It's possible to have one coil go bad on those. And make sure the plug didn't back itself out of the cylinder, I had one do that to me on the highway once. Wouldn't run without a lot of throttle input. Lots of dumb little things can make these bikes start running on one cylinder. Also try closing down the pilot jet on that side, might have vibrated open and it's flooding a bit. The jet adjusters have caps on them from the factory, if yours does not then it's a good bet the bike has a jet kit. The adjusters are right over the top of the starter and in the vertical plane. The screws that stick out the sides are the float bowl drains....

08-07-2005	#5 (permalink)
fret8 Newbie Join Date: Aug 2005 Posts: 5	spark plug give good spark, but I'm now thinking that I'm really not getting any gas into the cyclinder, any hints on how to double check this? I know i have gas in the bowls. Thanks

08-12-2005	#7 (permalink)
fret8 Newbie Join Date: Aug 2005 Posts: 5	problem fixed...bad spark plugs

08-12-2005	#8 (permalink)
fret8 Newbie Join Date: Aug 2005 Posts: 5	I put new plugs in but it seems to backfire just a little more then normal...could that be because of the plug gaps?

08-13-2005	#9 (permalink)
Redline Banned BTK Expert Join Date: Mar 2005 Location: Denver Colorado Posts: 459	EX500s have that problem. It's due to some emissions equipment on top of the engine. If it's backfiring, that actually means it's finally running right. If the backfiring really bothers you, I can tell you how to eliminate that emissions stuff.

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