I know it's not a banshee , but could use help

[banshee30705]

hey everyone , my friend wanted me to post this . He has a stock 2006 model yfz 450 all except a pipe . He said the yamaha shop supposably rejetted it when they put the pipe on . According to him the bike runs fine intil you hit topend then it cuts out . I told him it sounds like a possible jetting issue to me , but then again I'm no mechanic especially on them . I'm going to go ride the bike tommorrow , and see if I can't help him out . What do you guys think ?

[wacko2000]

Well usually you have to go up a few on the main when you pipe something..I wouldnt trust the dealership, Id pull thats carb and see what jets are in there, just so you boy knows what jets he is running anyway....

If the bike bogs and then comes alive he is rich on the main...

If the bike just goes flat and speed doesnt increase he is lean on top...

Better to be rich, If it was me I would find out what the stock jetting is and then check and see whats in my carb now.....

[locogato11283]

yea have him pull the main and see what size it is. any other mods? air intake or anything?

[Dave I.]

http://www.yfzcentral.com/invision/

[HotCarl]

the guy i ride with was having the same problems and I ended up tearing his carb off and going up 3 sizes from stock to get it to run up top. which wasn't the best thing to do, because now he is was to close to me when we drag race.