02 KX 125 Jetting ?

[LA Sledboy]

I just pulled the mainjet and its a 350 which FMF recommends for 0-1500 ft for their SST pipe. I ride at 7600 up to 9 or 10000 though and sometimes go down to around 5000. The bike wasnt performing badly at all with what should be a rich jet but can anyone recommend where I should be at with a jet?

 

[LA Sledboy]

It did spit out a lot of oil from the pipe and silencer but overall performance wasnt that bad I should add. The bike has an SST Gold pipe with a Power Core 2 silencer.

 

[KX02]

I have a 2002 KX and I was surprised that FMF recommended those stock jets when I saw them on their web site. If you ask me these bikes are jetted way rich, my bike spooged like crazy when new. For the warmer weather right now I'm running 2 sizes smaller main and pilot.

 

[LA Sledboy]

I just threw in a 300 and it seem to lose some hesitation it had before and gain some snap. It ran fine. With sleds when you go this high up in elevation its not uncommon to drop up to 10 jet sizes so 5 should be safe. I may drop more.

 

[Studboy]

5 sizes at once is a BIG jump. Have you done a proper plug chop yet? I'll bet that most of your spooge issues were from your pilot and needle, not your main jet.

 

[LA Sledboy]

Yes but the elevation that I ride at is 7000 feet higher than what the 350 was recommended for. It seemed to clean up the ride all around. I will keep an eye on the plug for a while but I think (hope) 5 sizes was fine.

 

[bschleuning]

2002 jetting

I just bought a 2002 kx125, it came from denver colorado and was ridden in the mountains, its all stock except a fmf fatty pipe, heres what i found inside the carb, the main jet stock is 350, it has a 270, it has the stock pilot 45, it has the stock needle 6beki-69 and the clip was on the second from the top groove , the stock setting is on the third groove from the top, i ride in nebraska which is around 4000 to 4500 feet, the spark plug was burning just a little lean, and it has a slight bog on the bottom end, not bad but noticable, i dropped the clip one notch to the stock setting, im going to ride it again soon and do a plug chop to see whats what, the inside of the exhaust is very dry, no spooge anywhere , if anyone else rides at close to this altitude let me know what your settings are, im guessing the 270 main is 7 sizes smaller than stock, the bike rips when its on the pipe, but i think i need to richen it up just a bit...thanks ..let me know