confused about jets

[stephen_48]

:? I just posted a message about a 200m that soots its plug. I was wondering if the jet sizes would affect the amount of fuel that enters the cylinder and if I should try a smaller jet. I know that there are a few jets in a carb and was wondering what you guys in the know think?

life is like a boghole... You need to jump in with all three tires.

Yes, you'll get less fuel using a smaller main jet. The main jet effects the mid to top-end circuit, it starts to override the low-end needle at about 1/4 throttle.

To adjust the richen up the top-end, go one jet number higher, and to lean it, go one number lower.

To adjust the low end, move the clip up or down. Moving the clip up will lean out the low-end, moving it down richens it up.

Make sure the carb is adjusted correctly before you start rejecting. A leaking valve seal, leaking piston rings, clogged air filter etc, can also foul plugs.

[Falstaff]

Don't play with your main jet too much. Like mentioned above check other variables first. You can get excess fuel from a choke valve not seating fully. Also if your needle valve is not seating properly it will let in too much fuel. Leaning out your jets can lead to a meltdown of your engine from lack of fuel/lubrication.
Good Luck!