[adbaldwi]

Hello,

This is my first post from a newbie. I purchase my first bike two weeks ago, it is a 2003 ex500 with 5,000 miles, everything was going fine until after the first week. I noticed that the right cylinder was missing, or not firing properly, but was sporadic and would go and come (I could feel the power loss on the road). After a few miles the bike was not able to idle anymore, to get home I had to hold the engine above 3,000 RPM otherwise it would stall at signals. I removed the spark plugs and the right had chalky black soot on it. I replaced both with DR9EA gaped at .028". I also removed the carbs and inspected all the components. All the jets were spotless. After placing the new spark plugs in, the bike started up fine with no choke and ran for 30secs @ idle, then stalled. After repeated attempts to start the bike, it finally turned over, but again would stall if I did not keep the engine above 3,000rpm, the right exhaust also smoked profusely. I removed the spark plugs and the right spark plug looked at if it had not been used, spotless with no deposits, slightly wet but I wasn't sure if it was from gas or water.

Both spark plugs had similar arcs when I pulled them out and tested them. I checked compression on both cylinders and both reached 180psi after several starts. Also, when I got the bike the coolant level was down slightly with no apparent leaks in the cooling system. I am going to check the ignition and wiring per clymer's handbook tomorrow morning, but have no idea what it could be.

What comes to mind to me is an ignition issue, ignition timing issue, valve, head gasket, and carb fuel/air ratio issue...

Could anyone pass on some advise? I'm not sure where to go from here...

Thanks!

 

[Jsvob03]

i have no experience on carbs, but it sounds like that is yor problem. id think its either a float problem or a plugged jet. you said everything looked ok, did you clean it anyways?

 

[fog]

In spite of your carb "cleaning" you have a carb problem. Sounds like either a classic #1, OK for you a plugged pilot jet, Or more likely a leaking float valve. Commonly called flooding.
Look at the float levels, and backflush the fuel line from the carbs to the tank and fit a fuel filter in-line.

Also just for Ha Ha's clean the insides of the plug boots.

These are the most common causes of your symptoms

 

[adbaldwi]

Thanks for the info? When I check the float to make sure it is 17mm what exactly do I measure from?

 

[adbaldwi]

Alright, thanks for pointing me in the correct direction! I took the carbs out studdied them with a fine tooth comb. I measured the floats and those where in spec. Looking into where the hangers go I think I saw a foreign object, so I back flowed gas through it. Put everything back together and walla! The bike runs so smooth now, now I just need to fix the slipping clutch problem and place an inline fuel filter... thanks for everything. I was giving up last night because I had no idea where to begin.