I have a buddies 2001 ex500 that I am trying to get running right. He bought it from some shady "mechanic" and hasn't had it running since. I took it apart last weekend and replaced the plugs, replaced the filters and fluids, and cleaned the carbs. The bike starts up just fine and sits at about 4k choked and about 1200 at idle. It idles just fine but if you try to twist the throttle it bogs at 2k and dies. I find it odd that it will sit at 4k just fine with the choke but then dies when you try to rev it past 2k. If I just crank back on the throttle it will rev just fine but its not smooth, it still tries to bog at 2k and you get a little puff of smoke. The problem is the manual I have for the bike doesn't have a single picture of the fuel/breather line routing so I am curious if they were hooked up wrong originally. I tried to let my buddy assemble everything so he could learn about his bike and he loosened up the throttle cables alot and I am not sure they got tightened back down enough, I am not sure if that could be causing issues or not. Any help or ideas would be great, I have to get this thing up and running this weekend.

 

Sounds like the main jet is plugged. I rode with a guy that started his bike and it would not run unless it was fully choked, he had to ride the bike all the way back in first gear with the choke on just to get home. He later took pics and said that when he took the carb apart the jets were plugged with crap. Especially the Main Jet.

 

Oh and welcome to the forums.

 

Yes indeed, welcome to KF.

If you know that you did a complete carb cleaning, and set the floats up properly. That prolly leaves a carb synchronization, vacuum leak or cable adjustment probability.