Ex-500.com - The home of the Kawasaki EX500 / Ninja 500R banner

1 - 11 of 11 Posts

·
Registered
Joined
·
12 Posts
Discussion Starter #1
Hello, i am currently working on a 94 EX500 and I have a surging problem like it wants to run out of gas. I have cleaned the carbs twice and i am currently running 2.5 turns out on the pilots. The bike also doesnt want to idle when cold, and by the time it warms up it is idling at 2k RPM. I know it has to do with the float height, but i need to know how to adjust them. Can i Use a micrometer to measure the float height? Do i need to remove the carbs from the bike to measure the float height?

Thanks in advance for the help.

Burkemotorcross
 

·
Registered
Joined
·
19,363 Posts
You can measure the float height externally by connecting a transparent hose to the drain and routing it up along side the carb. open the drain and the fuel level should be just about even with the bowl split line.

But that not your problem. Your pilot jet are plugged. If you didn't remove them and see light theought them your cleaning did nothing.

The no idle then racing is because you have the throttles set to open to keep the bike running on the main jets.

FOG
 

·
Registered
Joined
·
12 Posts
Discussion Starter #3
when i cleaned the carbs, i cleaned the pilots, and i saw light through them. I also followed bladecutters instructions off the old website to clean the carbs and they are clean(i cleaned them a week ago). the hesitation only happens when you ride the bike and not while it is in neutral. Can incorrect float height cause this? Or do i have an air leak? Also, when i check the float height, do i need to remove the carbs from the bike so they can be perfectly level, or does that matter? ???

Thanks again
 

·
Registered
Joined
·
19,363 Posts
Ok it sounds like it's flooding . that is too much fuel in entering the carbs than the engine needs. Not exactly a float problem more of a float valve problem. Yes you need to pull the carbs and remove the float valves and back flush the line back to the tank. Do this over a clean sheet of paper to see what comes out. I have seen several cases where an owner that has recently "cleaned" the carbs, has sheared off a bit of rubber gas line from the inside of the hose. this bit then travelled down to the float valve and lodged in it preventing it from closing all the way. See that this hasn't happened to you. While you have the carbs off and open, set the float height to 17mm above the cover split line when just resting on the springs.

Install a in line fuel filter now too.

FOG
 

·
Registered
Joined
·
19,363 Posts
No,

no leaks set up a gravity feed to the fuel line and lift the floats the flow should stop completly.

FOG
 

·
Registered
Joined
·
12 Posts
Discussion Starter #7
FOG said:
No,

no leaks set up a gravity feed to the fuel line and lift the floats the flow should stop completly.

FOG
I dont follow?

Do you mean hook up a external tank and press up on the floats and see if the fuel stops flowing?
 

·
Registered
Joined
·
12,314 Posts
to check the float height, take the bowl off. hold the carb so that the float hangs down, then tilt it back until the valve needle is just seated. the rod in the end of the valve should not be compressed. measure the distance from the carb body to the top of the float. like fog said the distance should be 17mm +/- 2mm (0.669 +/- 0.08in).

sorry the pic is so blurry, but i notated everything that you need to see.



1 - carb body
2 - float valve needle rod
3 - float
4 - float height.

4 is what you need to measure.
 

·
Registered
Joined
·
19,363 Posts
burkemotorcross said:
FOG said:
No,

no leaks set up a gravity feed to the fuel line and lift the floats the flow should stop completly.

FOG
I dont follow?

Do you mean hook up a external tank and press up on the floats and see if the fuel stops flowing?

Yes that's the Idea. to see if your float valves are really valves or leakers.

FOG
 

·
Registered
Joined
·
12 Posts
Discussion Starter #10
thanks for the help, i will pull the carbs a third time, check the float valves, clean the carbs again, and set the float valve height.

I will post my results when i am done.

Thanks again
 

·
Registered
Joined
·
790 Posts
results? I have the same issue!
 
1 - 11 of 11 Posts
Top