i have a yamaha warrior that sometimes pops and cracks through the pipe. it also has a black sutty residue around the pipe where the exhause comes out. what causes this?

 

running rich is normally the black residue ,butpoping and crack sounds lean ?

 

My warrior was doing the same thing and i figured it out after i burned up my rings their is a screw at the bottom of your carbs and just screw it in a little to make it run less rich. but the warrior stock carb is sooo crappy iam just geting a new carb. it helps alot

 

thanks for the info

 

that fuel screw only mixes the idle circuit to almost 1/4 throttle. you turn that in and you're neighbors will think it's the 4th of july. if you have to turn it out more than three times without the results your looking for then you need one size bigger pilot jet. as for your black exhaust go down one on the main jet. smaller main and bigger pilot will fix your problem or put the air box lid on.

 

If it just started all of a sudden, it might be something as small as water in the carb. Drain it and see what happens.