[aiden55]

Hello,

I purchased a '92 EX500 about a month ago, and it ran perfectly up until one week ago. As the rpms climbed, the engine would 'hiccup' as if out of fuel for a split second, and immediately continue to accellerate. These 'hiccups' would occur anywhere from 4,000-10,000 rpm. A few days later, the problem grew, and now the bike is runnning on the left cylinder anywhere below 7,000 rpm, after which the right cylinder kicks in instantly and the bike takes off. Furthermore, the bike has trouble idling, and accelerating from stops.

I figured it was a carburator problem, so I took the carbs out and cleaned the pilot jet, main jet, etc. I also cleaned the air filter while I had the tank off. I put everything back together, and although the bike ran a little smoother, the right cylinder still doesn't fire below 7,000 rpm and the 'hiccups' still persist.

Any other suggestions are greatly appreciated.

PS: any thoughts on using Shell Rotella engine oil?

Thanks

 

[Frog]

Try to verify if the spark plug boots are clean. The connector unscrew from the wire. You can cut 1/4 inch from the wire and rescrew it in. <= cheaper than getting new ones.

Rotella has been used by many in the 500 and no one has issues with it.

Do a bit of research for oil filters (the search box on the top right) Wal-Mart has a good quality oil filter made by Champion for about 3$

Keep us posted and welcome aboard !

 

[Mugwump]

After paying for Kaw filter, ouch, I decided to look at walmart. Sure enough the filter was listed. Not stocked. Guess I should write down the number and shop at some other part stores. How could the Kaw filter be that much better to be worth the money?

 

[aiden55]

The spark plug boots look clean, would you recommend that I change the spark plugs?

I think it's a fuel issue, because the right cylinder get much hotter than the left, ie. the mixture is too lean. Correct me if I am wrong.

Thanks

 

[alex182]

The spark plug boots look clean, would you recommend that I change the spark plugs?

I think it's a fuel issue, because the right cylinder get much hotter than the left, ie. the mixture is too lean. Correct me if I am wrong.

Thanks

If the right cyl. is getting hotter, that seems to indicate that's the one doing all the work. I had to clean my jets, but I also had a break in the power wire to my coil that would only intermittently allow power. Pull the plug and check your spark in both cyl's to see if one is weaker than the other thus not having decent combustion.

FOG will tell you to clean your pilot jets. Never a bad idea.

 

[Frog]

How could the Kaw filter be that much better to be worth the money?

It has a magical engravement on it saying Kawasaki which allows it to have a much higher price.. That's about it.

 

[aiden55]

If the right cyl. is getting hotter, that seems to indicate that's the one doing all the work. I had to clean my jets, but I also had a break in the power wire to my coil that would only intermittently allow power. Pull the plug and check your spark in both cyl's to see if one is weaker than the other thus not having decent combustion.

Thanks Alex, I will try the spark plugs.

The reason I believe the right cylinder is not firing is because the right muffler stays cold and doesn't warm up like the left muffler.

 

[Jsvob03]

I'm not speaking from motorcycle experience, but from general engine experience. It sounds like a problem related to spark, specifically the coil pack. I would first verify you have strong spark. I don't have a service manual yet, so i can't say check this, that, and this should be the result...but this should get u on ur way...good luck..

 

[fog]

FOG will not tell you to clean the Pilots, Although they may in fact be plugged that's not the problem. 7000 rpm is the white elephant too. the throttle opening to get to 7000 is the key. That side carb is flooding it's cylinder until the throttle is opened enough to allow sufficient air in to afford a decent combustion mix.

Fix the float valve problem on that carb. Almost certainly a piece of rubber sheared off the inside of the fuel line at the last time the line was attached. (when you cleaned the carbs).
Back flush the line to the tank over a clean white paper and see.

FOG

 

[aiden55]

I haven't had a chance to adjust the float valve or test the spark; but recently the bike has been acting better. I would like to throw this out and see if it rings any bells.

When I take it out for a ride, and park it for about 15 minutes, it starts right up and idles perfectly. As I accelerate, it runs fine until 2nd or 3rd gear, the bike is back to running on one cylinder.

 

[aiden55]

I forgot to mention that I added a carb cleaner additive into a full tank of gas a few days before cleaning the carbs.

 

[fog]

That little bit of information might change the diagnosis. You may have a plugged tank cap vent. if the tank is nearly full this could happen real fast.

But you need to tell everything if you expect expert advise. Or all you'll get is a lot of meaningless suggestions.

And the carb cleaner won't hurt anything, It won't do anything either.

FOG

 

[aiden55]

Thanks FOG, I will check that out tonight.

 

[aiden55]

I don't think the tank cap vent was plugged.

If that was my problem, then the bike should idle smoothly when the cap is open to atmospheric pressure. Correct?

 

[fog]

Yes,
It sounds like the pilot je is pluggeg on that carb or it's flooding. one or the other.

FOG

 

[aiden55]

Thanks for all your help.

How would you recommend I adjust the float valve, as I am not very familiar with carburators.

Aiden

 

[Frog]

FOG has a new service available, check this up : http://www.ex-500.com/index.php/topic,2048.0.html

 

[aiden55]

Hey FOG, sorry to burst your bubble, but I took the carbs out again.

The foat height was exactly 17mm on each carb, the pilot screws were 2.25 turns out (from the Hayne's Manual) and the pilot jets and everything else was clean. Furthermore, the problem is getting worse; today, the second cylinder didn't fire anywhere in the rpm range.

On another note, does anybody know anything about the NGK D8EA spark plug? I went to the store for NGK D9EA's (Canadian version of NGK DR9EA), but they didn't stock them, and their computer says the NGK D8EA is the spark plug for the '92 model.

I appreciate all the help.

 

[aiden55]

SUCCESS!!

After changing the spark plugs, the bike runs like a dream.

Thanks for all the help.