i have a 2002 600xc that i drag race with k&n's.....i am vented under the hood would that make it richer or leaner compared to having the air box on ....the reason i ask is been having a problem get it to pull down the track....comes off the line great but after that it goes flat....i can run it at 1/4 to 1\2 throttle and it pulls great but soon as i go w.o.t it stops pulling...thought it was clutching but have played with that for 2 years, time to look somewhere other then that... the only other thing i can think of is that the exhausted might be plugged up alittle ...going to check that first then start into the fuel system... one other thing, cant get this thing to rev past 7900-8000 no matter what i do....light weights...heavier weights....stiff springs...light springs always runs the same(tach is out 200)

any suggestion or things to look for would be great....thanks fur292

K&N's will make it run leaner than with the stock airbox.

is it because there is less vacuum when u vent under the hood with no air box?

More air going into the carbs than with the airbox. You should jet up at least four sizes to start. Does your sled have an exhaust gas temperature gauge? If not, it may be wise to install one.

no temp gauges hopefully soon...it i did what is right temp to run it at? so u are saying that i am way to lean on the top....ok i will try up jetting but every on that i talk to that has this type of sled and races it is running 350-370's in the summer(witch would be a couple up for the winter) but i have seen stranger things and not saying they are telling me the truth..was out last week at around -3 C with 400's.

thanks for the info, very much appreciated...every little bit helps with this on going struggle...fell free to and to it

thanks

The K&Ns will lean it out and underhood venting will richen it so difficult to say where you are so I am with Zog and say try to richen it as it is safer this way!!

Once you get your EGT gauges, 1200 - 1250 F is ideal.

thanks...i will give a try

Originally posted by Zog@Feb 20 2005, 08:54 PM
Once you get your EGT gauges, 1200 - 1250 F is ideal.
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I thought this varied? I know mine at 1150 looks pretty good. I won;t let it get that hot, although if it is OK at that temp, mine should fly :)

i'm not sure what they do yet because i have never used them...i have read somewhere else that temp is right but i also thought they varied... so do u get them to that temp before u come off the line or is that the temp it should run down the track... if anyone knows of someone selling some egt in canada let me know...would like exhaust temp, tach and playback on it

Originally posted by fur292@Feb 23 2005, 10:34 PM
i'm not sure what they do yet because i have never used them...i have read somewhere else that temp is right but i also thought they varied... so do u get them to that temp before u come off the line or is that the temp it should run down the track... if anyone knows of someone selling some egt in canada let me know...would like exhaust temp, tach and playback on it
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the k+n's will lean it out=more air flow.as far as whether you are running rich or lean,what do your plugs look like?i went up 3 sizes on my 670 when i added the k+n's.
is your jetting correct for the temps you are running in?if you're jetted for -30 and are running in 20 degree weather then you'll already be 5 sizes rich.

i'd say take a run and check your plugs first.if you've been running like this for 2 years i don't think it is running lean or you would have burnt down by now.i think you're way too rich.

"ok i will try up jetting but every on that i talk to that has this type of sled and races it is running 350-370's in the summer(witch would be a couple up for the winter) "

are you running 330's-350's in the winter with the stock air box?so back to the 5 sizes rich running at 20 degrees,+2 more sizes up you'd be 7 sizes too rich.if this is the case i'd drop 2 sizes right off the bat and take a run,check your plugs, and so on till the plugs look good.

i agree with swish because if he was too lean he would have tons of power right up till the time he smoked his engine