I have a 03 ZX9.... My problem lately is, my bike keeps bogging down... I will start out fine at about 1500 rpmsbut within 10 to 15 mins, my RPMS get down pretty low to where my engine almost cuts out... Anyone know y this could be?? I also noticed that when it does it, my gauge lights seem to dim a little too.... What the heck is wrong???

 

I'd prolly start with the basics. Check the battery, check the charging system along with making sure the ground is good.

 

Agree with ^Drag; sounds like the charging system, and maybe specifically the alternator heating-up(?) Something is acting like a power soak once your bike gets up to temp.

 

Check the regulator. Id bet thats the problem. Take a volt meter and check it at your bettery. If its anywhere in the neighborhood of 12 your good. Then check your OUTPUT (not input, very important) at the regulator. Anywhere below and youve found your problem. Your battery is producing enough charge to crank and even idle, but if your regulator isnt regulating, you arent goingto have enough juice to maintain.

 

+1..
does it smell funny like its running rich or leaning out? could be the slight possibility of a fuel stravation issue..
definitely a thermal defect of some sort.. if you want to play with the electrical stuff, get a can of computer duster stuff... turn it upside-down and spray your electronics. inverting it will make it spray ice-cold..

if theres a noticable change in your bikes behavior, you've found the culprit.. it'll be impossible to spray your stator.. theres ways to check that however....

i'll give it a day or 2 to see whether you'll need that explaination..

good luck bro!