PLEASE HELP ME! Carb question.

Ok so I put new plugs in it and she runs great for about 5 minutes than it starts misfiring the #3 cylinder so i take it home pull the plug out and its totaly black and sooty, so i clean the plug put it back in runs good for another 5 mins, Take it home and pull the plug and its crazy black again!! I cant figure it out, All the other plug are good and this is a new thing it just started tonight after i re adjusted the pilots mabye it has something to do with the pilot jet in that cylinder idk, PLEASE HELP ME<

 

Check the vacuum line that goes to the petcock and see if its wet with gas. If it is your diaphram is bad and you will need to rebuild it. Charcal has the parts.

 

Ya but if that was the prob it would foul on all the plugs not just the #3

 

sounds like your petcock is leaking, do you know how to test it?

 

The petcock leaks but i have a new one on the way, It just doesant make sence that #3 would be bad and not the rest, correct me if i am wrong.

 

Ok If youhave the stock tank and petcock on this bike. The petcock has a vacuum line connected to the #3 carb holder. If the diaphram is bad it will pull fuel through that little vacuum line right into # three cylinder. Making it so rich it will foul you plug and wash your rings out. Plug the vacuum line and put it on prime and go for a ride and see if the problem goes away.

 

No. If the diaphragm is leaking, fuel will be sucked in through the vacuum line into the intake and raw, extra gas will create the conditions you are seeing.
Have a look. If the fuel petcock diaphragm is intact, you will need to look very closely at carb #3. Have you pulled and cleaned the carbs at all? If so, when and what did you find?

 

Remember to not leave it on prime when you come back from your ride if your needles and seats are bad it will flood your whole engine.

 

Ya i was unawear the vacuume line went to #3 the diaphram leaks for sure its been like that for awhile, I will try the prime thing for sure, and yes I cleaned the carbs like 3 months ago and the fuel rail was all pluged right at the end by #4 mostly because the tank is not in the best shape, well thanks guys I apprecate it

 

Install a fuel filter for sure. Let us know how it runs when you get the petcock in.

 

Double check the float level on #3.
If its too high it will run very rich.

 

Alright guys well i plugged the vacuum line and caped the vacuum post on the petcock and the bike runs way way way better, im not sure how long its been leaking like that but i made a huge diff, the bike runs way smoother, Thank you for all your assistance and be prepaired for more issues as they come along lol

 

It could be as simple as the idle screw being turned to far out. It's the little screw just in front of the carb diaphram. On each carb, they should turned out 2.5 turns from lightly seated. Check the other carbs and working backwards, see how many turns they are out. Getting black sooty plugs is the result of too rich conditions on that carb. Good luck.