My 2000 recon 250 sputters alot under 3/4 to full throttle in 3rd gear and up..I have cleaned the carb 3 times (everything)...flushed the tank, cleaned the petcock, replaced the fuel lines and vac lines, when i run it hard, i kill the engine and pull the plug and it is white, i have put the needle on the richest setting, and messed with the air/fuel screw, and still a lean white plug!...I am just about ready to take it to the shop!, but that is a little too expensive with having 2 kids.....can anyone help me figure this out before i loose my mind, I have read all posts that i can find, and have done it all PLEASE HELP!

 

have you tried richening your pilot jet? locate it on the bottom of your carb, small brass skrew outside of bowl. turn it OUT about 1/2 turn to start, then 1/4 turn at a time. see if that helps you out any

also, have you checked for air leaks? that would cause it to run lean as well

 

The screw on the bottom of the carb is the air fuel screw at least that is what i thought it was...i tried to richen it up and it did nothing...i thought the pilot screw is under the brass cap and would need drilled out to access it.....as far as air leaks, there is none...i used carb cleaner to check while running...none found..any other ideas....maybe CDI?...I hope not...thanks!

 

OK.....Now i'm really stumped...I removed the airbox lid and ran it, and no sputtering, More air makes it leaner, right?....so WTF?....now what do i do?..I can't run it with no lid, thats just stupid!..any ideas?

 

ok, going back to basics. are you running the correct range plug? if so then i doubt its a CDI problem. i know what i described as the pilot jet. OUT is richer. it dose help govern the fuel/air mix on khein carbs. hmm..you can run it with the lide off, i dont think its stupid unless you need your mechine 2 be waterproof. but now you are letting in more air, this should lean the mixture. but if you where too rich this would help that problem.

ik you said you did the plug test. did you do it under load, going threw the gears? or just reving it up and not moveing? place in a <u>new</u> spark plug and redo this test while going threw the gears. kill/check it once when it sputters in top gear. then kill/check it once with the lid off in top gear when it would normally be sputtering. the more info you can provide the more help people can provide.

 

I did the plug test under load...and got the lean result....it is the right plug...and i would like my machine to be waterproof...i will do the plug test with the lid off tomorow, know adding more air makes it lean, that is why i'm so damn confused... honestly it doesn't make sense...thanks for your help, i'll update as soon as i can do some more testing.

 

possibly if you richened the pilot then took the lid off it would produce a better result.

there is another way to do an intake leak test...take off the air filter, turn kill switch off. place your hand over the inteke tightly, then hit the starter so the engine turns over a couple times. this will create a vaccume in the intake. if the vaccume lasts for 30+ seconds your good. if it lasts just a few seconds you do have a leak. the carb cleaner test will find big leaks if you spray it right on the leak. not small leaks or at odd angles...

there really has to be more air leaning out the fuel mix. its possible with the lid off ther isnt as much of a vaccume to suck extra air from a leak

 

are you useing stock air filter? these bikes come very lean from factory. i had one for the kids a couple years ago and my neighbor still has his 2 also. these bikes didnt run very well on the high end as you described. i removed the stock 95 jet and replaced with several diff sizes and found a 102 worked best. i added a uni air filter also

 

I hate to say this, but your choke isn't on is it?

 

well i did a load test with the lid off, and still a lean result.The sputtering is gone with the lid off..my choke is not on..and it is a stock air filter...what the hell else could it be?...i'm really out of ideas...maybe i can drop to a colder plug?...i dunno!