I know this topic has been covered as I have read so many posts that my head is spinning. I thought I would ask an exact question and hope to get an exact answer.

Background - Fully stock 2006 KLX250S - Planning on pipe, jet, airbox, and one tooth down in front.

Specific Questions -

1-Will a full stock exhaust from a 98 KLX300 fit an 06 KLX250S?
2- If so, are there any modifications needed? If not, what years will fit?
3- With a KLX300 stock header and muffler, what specific carb setting and air box setting should be used? Example, New snorkle, lid off, lid cut open, etc. Example, 125 main, 45 pilot, third clip, etc. (Part numbers would be great)
4- Does anyone know the part number and amount of teeth for a new front sprocket? (Please advise if the stock chain won't work)
5- Is there anything else that I should do right now or would this be a good start for inexpensive mods?
6-If so, please explain.

Thank you all for the anticipated responses. I am looking for feedback from people that have first hand experience with this set-up.

Again, I have reviewed every link and I know everyone has an opinion and most of them differ so I was hoping to get some info from the people that are actually running a stock KLX300 exhaust. Most importantly what carb/airbox set up and if they have tried different settings.

 

1-Will a full stock exhaust from a 98 KLX300 fit an 06 KLX250S?--- yes should
2- If so, are there any modifications needed? If not, what years will fit? no pretty sure any klx300 exhaust will
3- With a KLX300 stock header and muffler, what specific carb setting and air box setting should be used? Example, New snorkle, lid off, lid cut open, etc. Example, 125 main, 45 pilot, third clip, etc. (Part numbers would be great) i would start with 125 main, stock pilot, 2.5 turns on the a/f screw, N1TC needle-second clip position. (this is all a start, everyones is not exactly the same) just take the snorkel off of the lid.
4- Does anyone know the part number and amount of teeth for a new front sprocket? (Please advise if the stock chain won't work)13t front sprocket, moose makes one....

 

ok and really, did you ever look at a parts catalog? they have the moose part # there..... and there is a search feature of this site that should turn up all the info you requested... i cant count how many times all of this has been covered....[>:] its ok though... ill let it slide this time.....

 

Drill the slide too. I did 7/64 on OEM parts, #32 with DJ kit.

 

Stock 300 full exhaust works just fine, over 5000 miles on mine and counting. I started with a 125 main, stock pilot, 2 turns out on the a/f screw (the one hidden under the plug on the bottom of the carb) airbox lid on but snorkel removed, n1tc needle on slot 2, and had a 1 1/2" diameter downturn put on the end of the pipe. Kinda like the one on the Muzzy. I've since cut a bigger hole in the airbox and removed the downturn on the pipe and went to a 128 main but I think its a tad rich and I might go back to the 125. I live at ~300 feet above sea level.




And with the downturn...

 

Honda XR650L sprocket works, I have one on mine

 

Make sure you get the XR650L and not the XR650R. I got the "R" firstby mistake and it didn't fit so well...

 

I think that the 250r ninja sprocket also works.

 

How much difference does taking the end cap off make in sound and also power? Do the cops turn their heads when you drive by? Is that tip you made a 1 1/2" size?
Thanks,
db

 

With the end cap it would be no better than a stock 205S muffler, off is the only way to bother running it.