04 yz250 confused

[bush ranger]

Hello,



I have an 04 yz250 and cant get rid of the oil dripping out of the silencer. I run full synthetic mobil 2t at 40:1 standard jetting except for a 48pj. I have a mate with a 03 and his is doing it on a different oil(motul 800) so it cant be the oil type. I live at 500m above sea level and the temp is at the moment 10-15 degrees celcius but will go to 30-35 in summer. I did a plug chop and it was perfect. The bike has the symptoms of running lean. Why i think this is when u pull up from riding it hard it idles high for a few seconds. The air screw is set at 0.5 turn out and this rectifys this.I am a little confused as i am rich on the air screw but it seems i have to go lean on the jets to eliminate the spooge. Any help would be greatley appreciated.


Thanks

[Satch0922]

Welcome to ATM !

IF your air screw is only .5 turns out then you are WAY rich on the needle. I am not the jetting expert as jetting a bike where I live is fairly easy.

I would like to refer you to our Knowledge Base Forums. There is a weath of info there.

Check this thread out Jetting

[Blue 250]

Dont your mean the Pilot jet? Try putting it back to stock at 7/8 of a turn out from fully closed and see if it helps. It'll be a leaner right off idle. Why did you go down on the pilot? You shouldn't have to go leaner on the pilot unless you had the airscrew out more than 2.5 turns. Also, the only jet you can go by from the plug is the main and it'll tell if its the correct heat range. The plug has to be fresh and you then need to do a plug chop and look way down at the base of the insulator. The tip just tells you if you got the right heat range of a plug. By running the 40:1 you are actually making the bike run richer. Try all stock jetting while mixing 32:1. By running 32:1 your motor will last longer. I'm not trying to sound like some smartass, I'm just telling you what I know.

[bush ranger]

Thanks for your input guys. I will try the advice you guys have given me.

[Satch0922]

correct....pilot jet....