ok sorry if this has been covered before but i just got a 05 ds650x and it has a k&n air filter and a fmf slip on exhaust. the person i got it from did not even own tools so i don't think it has been re jetted or any carb mods/adjustments at all have been made. it starts easy (no choke), idles, and runs fine but after about 5min the fan comes on and does not shut off until i kill the motor. i ordered a moose jet kit for it. but when i called the dealer to ask what they would charge to install it they told me that if it doesn't pop,bang, or backfire then my problem is with the cooling system not fuel. they also told me that its normal to not rejet the carb when installing the bolt ons mentioned above but most people say different in things i read online. the cooling system seems to be fine also. i have checked the coolant and its clean,green,and full. the thermostat works fine. should i rejet the carb? is it possible that the stock settings would be fine when there is more airflow?

 

The shop you talked to don't know what they are talking about. Yes you have to re-jet after exhaust and intake mods. You didn't say if you still had the air box lid on. You will need to increase the main jet size and most like move the clip. Both are pretty easy to do, but if the carb has never been apart it a little tricky. The 4 Phillip screws that the float bowl on are nasty tight. You will want to grab 4 Allen head screws to replace them with. Not sure where you live for altitude but you will most likely want to move up to about a 175 main jet (stock style), think 160 or 165 is stock. Then drop your clip 1 slot.

 

thank you for the info... yes, i do have the air box lid on. is it worth it to take it off? i do go thru a little water but nothing over 3/4 of the hight of the tire and only at low speed. i got the moose jet kit for it yesterday and a gasket so ill tear into it this weekend i dont have the instructions to it with me but i think its same the as you mentioned above. (i live in Michigan. google says my altitude is 750ft to 800ft).