black sludge from pipe

[racerr88]

Hey guys, I hope someone can help with this problem I've had for a few months now. I have a 05' YZ125 w/Gorr 144 kit installed. I have played with the jetting for a while now but after 2 hours of riding/racing I am getting this black sludge/oily liquid leaking all the way down my pipe and onto the swingarm, it is also comming from the vent tube off the power valve cover. I feel I have the bike jetted pretty good. Sp plug looks fine. I do HS racing so there is some high and low speed riding. Has power-now,moose reed spacer,Boyseen carbon reeds,no-toil air filter,FMF Fatty pipe w/Q muffler, 144 Eric Gore kit, Use Motul800 racing oil with 93 octane gas 60:1. Stock carb with 420 main, 40 pilot, Cilp at #4 and air screw 2 1/2 out. I've adjusted the carb leaner and richer but still get the funky black stuff. Thanks for the help !

 

[Squid_uk]

I get a similar resin as well, i think it is just the oil from the fuel mixture

 

[BSWIFT]

What pre-mix oil are you using? I ran Yamalube 2R and got the same on my 250. I'm switching to something else. Seems the overflow vent really spits it out and must be fairly common.

 

[cr250pro]

Yeah, I have the same problem. I used the right 32:1 oil:fuel mixture. I also think this is just normal. It is really hard to clean off and pisses me off. Peace

 

[KX02]

If your bike is jetted correctly you should have little or no goop coming out of your silencer. Running a fuel/oil ratio of 60:1 in a 125 sounds pretty scary to me.

 

[racerr88]

I am using Motul 800 off-road racing synthetic. I have talked to 2 different Motul Reps. and they said I could run up to 66:1 ratio with their oil. Yeah, I probably would have to rebuild everyother race also ! I have tried 40:1 and 50:1 but still the same result. Thanks for the help though guys !