2001 CR250 Carb help...

[QuentinCR250]

Hi All, I have a 01 CR250 which is running the standard Mikuni Carb and jetting, I have done alot of reading on here and everything implys the 01 was way to rich in the bottom end, From what I can make out my bike does indeed appear to be rich at the bottom end. There are many different ideas in the forums some people have modifcations to the carb and some say that even by re jetting the Mikuni is a difficult carb to get right. Is there anyone here who has had a 01 CR250 and made a change which fixed this problem? obviously it would be good if I can fix the existing carb, but if the only way is to replace it with a Kehin off say a 2000 model I would be prepared to do this. Are there any aftermarket carbs which would be better than any of the stock options? Thanks in advance for any help to get this problem sorted out.

 

[84cr125flyer]

2001 CR250 JETTING
Jet................Stock..............Reccomended..............Altitude
Mainjet..... ...420....................430...............................400 - 420
Pilot jet........35.....................30.................................30-35
Needle.........6BEH1-73..........6BEH2-75......................Stock
Clip... .........3rd.....................2nd...............................Stock
Air screw.... 1.5 turns............1.75 ..............................Stock
Slide............4.0....................5.0................................Stock

This was suggested by everyone's favorit DB Mag, but I'm at an altitude of about 4500 ft on average and this is what I use: 390 Main, 32.5 Pilot, stock needle, 3rd clip, airscrew 1 3/4 turn, stock slide and a S-7 Jet Needle ((Sudco P/N 003-722). I'm also running a Pro-Circuit Platinum 2 pipe, Pro-Circuit shorty silencer and V-Force 2 reeds; other than that the motors stock, so far. Hope this helps.

 

[QuentinCR250]

Thanks for your reply, I guess one of the main questions I am trying to work out is, is the S7 Nozzle still a good option for owners of the 2001 CR, or is it better to go for an S8 Nozzle. Another thing how good are the JDJetting kits, thats another option that may or may not be better than playing around with the S7 or S8 nozzle's any more ideas or reccomendations? cheers.. :bang: :bang:

 

[mxneagle]

I cut my slide and it worked well, I can't remember what my other specs are though. I'm sure I went smaller on the pilot and I put different needle in it. You may still be able to do a search on this as it was pretty hot topic back in '01.

 

[yankeefan4life72]

are these specs good for an '02 cr250 as well??I was also wondering about the jd jet kit any opinions out there on the jet kit?My bike is rich too

 

[84cr125flyer]

I didn't want to modify my slide, I don't have the specs on what to modify it to, so, instead of winging it, I went with the smaller nozzle. You could go with the S-8 Nozzle, but since I am at a higher altitude, I made an educated guess and was almost spot on. I may go one size smaller on the pilot jet, my spark plug color is a smidge dark hinting I'm still a little rich.

 

[James]

I use the S-8 nozzle, 30 pilot, and a 390/400 main. 430 would be WAY RICH for me at 600-1000 feet unless it was near freezing. I have put the Keihin from my 00 CR250 on my 01 a few times and I didn't get any spectacular results...your results may vary. My 02 seems to jet about the same as the 01 and the 00 for that matter

 

[QuentinCR250]

Thanks guys, gives me more to work on....

 

[parkerCR]

get the keihin. I have the same bike and it is much better