Black Smoke

I just finished motor work on my bike, which was hotcams, port and polish, and a new top end. Now, whenever i go to start it, it has black smoke coming from the exhaust pipe. My teacher in school, me, and my dad think its too rich.Any thoughts? :thumbsup: :thumbsup:

Is this only when you start it or does it run like that?

umm..when its cold, its really black, and when its warmer, its barely noticable, but still there a little.

rich. what year of bike?

2004, i talked to my teacher today and he said that it is running extremely rich. for some reason, it wasnt until today until it "clicked" that it is rich, when i looked at a picture from the other day, and i had a 4-5 inch long flame coming from the pipe. Im gonna go try and fix it, most likely with leaner jets, but i will try turning the fuel screw in to see if that helps any. Thanks for all the input so far!!! :thumbsup:

A common mistake is to assemble the carb slide incorrectly, usually with the spring plate upside down. Makes the bike run rather badly.

And, what's your air filter look like?

my friends 06 yx250f blows a bit of black stock. its the only bike (4 stroke) that i have seen do that. so i would ask your dealer if its a yami thing??

my stupid friend(yes, i only have one of them) revs the :thumbsup: out of his bike as soon as he starts it. it smokes black like crazy! this is off topic but i gotta take a pic of this thing one day. hes way over weight so all he can do is make a hell of alot of noise.

A common mistake is to assemble the carb slide incorrectly, usually with the spring plate upside down. Makes the bike run rather badly.

And, what's your air filter look like?

I never disassembled the carb, just took it off. The only thing i took apart was, i took off the throttle cables. I know i need a new air filter, but even last season, with a sand and dirt covered filter, it wouldnt blow black smoke.

my friends 06 yx250f blows a bit of black stock. its the only bike (4 stroke) that i have seen do that. so i would ask your dealer if its a yami thing??

nah its not a yami thing, it just started doing it when i put it all back together. I just have a feeling, and am almost positive its just extremely rich. Its shooting flames from the pipe.lol

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