sometimes, out of no where, the engine will stumble I guess is the word, it loses power and won't rev, it kinda acts like the choke is on or it's running out of gas. I have to play with the throttle, let it idle for a bit then it will run and rev fine. I thought maybe I got some bad gas, but I have since put new gas in there and it will still sometimes do this. could it be a bad CDI or something? I wiggled all the wires with the engine running, trying to make the problem surface but no luck. oh yeah the plug is new and looks good.

any ideas? is this a common 300ex problem??

thanks

 

Its probably just over loading and flooding. Happens to me sometimes also. Just try to clean it out.

 

how do I "clean it out"??

if it's overloading is it a jetting problem??

 

I had this problem with my 250x some time ago. I checked it all and came to the conclusion that it was fuel. It would always do it to me after a jump ...then it dawned on me. I looked in the tank when it was very low I saw a mud like fluid in the bottom. Turns out it was water. It is easy to get it in there but not to get it out . Under normal riding it stayed below the fuel pick up and caused no problems but when I jumped it sent a nasty slug of water on it's way to the carb. Take a look in your tank if you see it..thats the prob. You'll need to remove and drain the tank. The last bit of it you will have to soak up with some towels since the petcock hole is raised inside and you will not be able to just pour it out. It worked for me. Hope it helps you.

 

THAT'S IT!!!!

I checked the gas tank and there is this rust colored crap all in there on the bottom. I tried to suck it out witha turkey baster, i got most of it but there is still some in there. I guess I will remove the fuel selector valve, let the fuel drain out then like you said use some rage to soak up the rest of the crap in there. THANKS A MILLION!!!!!!!!!!!!!!!!!

 

Who would have thought! I am having a problem something like that bu mine acts up when it gets wet!

 

Well if your problem is only happening when the bike gets wet them I would be looking into a short in the ignition. Look at the spark plug wire and wires for the coil..... make sure they are not grounding out. You can try spraying wires, including the inside or the spark plug boot, with WD40 or sylicon spray. Tish will keep the water dispersed and avoid grounding out. I loose plug can do it also.

 

What is a good way to waterproof the electrical so this won't happen?

 

You should be able to pick up these special 'tubes' at any hardware store near you. You slip them over you wires and connections, heat them up, and they shrink and compress it all together. water tight!
p.s. come in various colours

 

my friend had the same problem it started to sputter when it was shaken around he was goingcrazy trying to find the problem then he look in his airfilter box and it had some water in it after he got the water out it ran fine