Please Help Fast !!!!!

[yamracer58]

i went to start by bike today and it would start but it was bogging down really low and would back fire a couple of times,so i shut it off and started it again and it did the same thing, so i pulled the plug and it was crisp black with a tiny bit of oil on it. any ideas what could of caused the back fire, also the smoke was a tan color.
thanks
2001 YZ 125

[FmX_Blaster]

bad gas?

[YzRacer#53]

Jetting or gas air filter. try to clean your air filter first and drain the gas and put fresh gas in. if that fails then jetting.

[yamracer58]

its fresh gas mixed 40:1

[Roostman]

Sounds like a fouled plug to me.

[yamracer58]

would a fouled plug cause backfireing?

[Roostman]

yes

[KX02]

I'm not sure I've ever heard a 2 stroke backfire! When was the last time you rode this bike? Did it run normally then? It could just be a bad plug. If you have ridden this bike before and it ran fine, I don't see jetting being the problem. I'd try a new plug and clean the filter for starters.

[Snowsk5054]

Last time I heard a backfire, was from my DS 80. When I turned on the choke, and started it, it bogged, backfired, then died. It had fuel in the crankcase. My opinion.

[beanpolio]

Bad plug and/or VERY dirty air filter. Did you check the air filter?

[crdemon]

Originally posted by KX02
I'm not sure I've ever heard a 2 stroke backfire!

Its really loud before i replaced the coil on my cr it would backfire once in a while.

[carey14]

so what was the verdict???