i just replaced the rubber boot that runs from the carburator to the head,because it was cracked and it was back firing out of the exaust.now when i run WOT it hesitates and does not get up to full speed.it maxes out at around 5600 rpms where before it max out at around6200rpms.i checked the plugs and one of them was fouled.it runs good until you get to around3/4to full throttle.before i changed the boot it ran fine.i dont understand why changing the boot would cause this because the machine is stock,no mods.and it never did this when the old boot was good.does anybody have an idea what the cause might be?

 

i think that you might have a fuel line restricted or a jey restricted... maybe a rejet kit like dynojet would be worth looking into

 

How many miles are on it? Maybe you have a worn jet needle and needle jet. Make sure you have enough freeplay in the choke cable.It could be partially on if the cable was kinked when you change the boot.

 

Is it an efi model you might of messed up the (tps) throttle position sensor?

 

i just replaced the rubber boot that runs from the carburator to the head