1999 KX250 rattling help!! please!!

[weldspipe]

Hi,
bought this 1999 kx250 about 2 months ago. Rode the bike about 5 different times, all rides being around an hour or two maybe more. Typical saturday and sunday riding. Went out to Hollister last weekend and the bike starts making a rattling noise (as listed in this exact video i found ), at first I thought it was an exhaust leak but got a gnarly header still makes same noise. I have been researching all day and people say its either a spark plug, bad fuel mixture, power valve rattling, or literally nothing at all, saying its just a "kawie" noise. Does anyone have any experience with this rattle? it increases as RPM increases and does it at idle, definitely not the clutch I've held it in and still makes the same noise. Its driving me crazy, just need some help. Thanks!!!
Jacob

 

[weldspipe]

Another thing is that the bike is completely the same as when I bought it, minus the noise. Same power output, if anything have more torque because of the expansion pipe i put on. Literally bike runs exactly the same, just rattles from the engine now.

 

[The Redrider]

Hi,
bought this 1999 kx250 about 2 months ago. Rode the bike about 5 different times, all rides being around an hour or two maybe more. Typical saturday and sunday riding. Went out to Hollister last weekend and the bike starts making a rattling noise (as listed in this exact video i found ), at first I thought it was an exhaust leak but got a gnarly header still makes same noise. I have been researching all day and people say its either a spark plug, bad fuel mixture, power valve rattling, or literally nothing at all, saying its just a "kawie" noise. Does anyone have any experience with this rattle? it increases as RPM increases and does it at idle, definitely not the clutch I've held it in and still makes the same noise. Its driving me crazy, just need some help. Thanks!!!
Jacob

Sounds like my 2 classic Cr's, they all make those noises, if you had a loose rod bearing, it would make a bump, bump noise when you gas it, usually it happens after you let off the throttle. My 86 cr made that bump, bump noise, i sold it cheaply and informed the next owner about it..Relax dude, you will be ok...