New banshee help

[2001Shee]

Hey guys just bought my first banshee, I got her all put together earlier this weekend. My problem is that when at full throttle it begins to bog down very badly, but if you back off a little bit it runs very strong. From reading on here I figure this problem could be my mains, but not positive. If anyone has any suggestions I would really appreciate it!

 

Its a 2001 banshee, pro circuit pipes and silencers, k&n filter, fmf reeds, 28mm mikuni flat slides, and an accel hot coil. I ride around 500ft above sea level

[Wildcardracing]

What is your current jetting? Sounds rich on the mains to me. Do a search in this forum and find out how to do a plug chop, it will be invaluable to you.

[locogato11283]

jetting.. air filter clean?

[2001Shee]

thanks for the replys guys. the air filter is clean. i bought the carbs used so i have no idea what size jets he had in them. i figured its a jetting problem i just dont have experience in carb work i have always had FI. it just has me stumped because the thing runs great until you try to open it all the way up, its like theres a line where it just hits a wall. it sits and idles all day long also. think i have a feel for the plug chop so im going to give that a shot when i get back from school. i run 32:1 on the ngk br8es plugs

[locogato11283]

no need for a plug chop. take it for a ride. get it good and warm. do a wide open throttle plug check in 5th or 6th gear. run it WOT for a few seconds and shut it down. pull the plugs and see what they look like.

 

dark brown or black = too rich. drop the main size down.

tan = just about right.

white = lean. raise the main size.

[2001Shee]

all right guys school finally got out last week, headed home to get at the banshee... got it warmed up, then ran it wot. pulled the plugs and sure enough they were black and wet... looks like were dropping the mains down. thanks everyone for the input, ill let you know how it turns out. checked the air screws and set them to 1 1/2 turns out.

[2001Shee]

Got after it now that I am out of school. Found that it had 280 mains in it. Had some 260 laying around so I threw them in. Got everything strapped back up, fired her up and its revving very high, I thought i accidentally messed with the idle screw while the carbs were off so tried adjusting them and it just stays running really fast, no matter what I do with the idle screws... took it for a little ride and its still bogging and backfiring at full throttle. I'm going to be working on it some more today and will let you know how it turns out. This thing is pissing me off..