PK 26 to PWK 28

[Rota Ash]

hey i was gonna buy a new carb for my girlfriends 97 KX100, she has the old style PK 26 carby on it and i was planning on changing it to a PWK 28, would it be as simple as just changing the jets across to the new PWK carb, is the needle interchangable from old to new, and is it even worth it, her bike has bugger all bottom end power will this help or should i just put a flywheel weight on it??

[SachsGS]

You are attempting to go the wrong way, for increased bottom end you want to install a carb with a smaller venturi rather then larger. As well, a heavier flywheel will reduce wheelspin and stalling, but will not create any additional bottom end.

I can't prove it, but my experiences with some of these 85/100 carbs leads me to believe they are "top end" carbs and that the designers weren't too concerned with low end performance.I myself would lean towards something like a round slide 24mm Mikuni for a noticeable increase in bottom end performance. Mind you, the porting and pipe of that KX100 were designed with top end performance, so you are fighting that as well. I have gone the old fashioned round slide Mikuni route in the past and it does work.

[Rota Ash]

might just stick the the stocker then, i have a set of dual stage reeds to throw in it, hopefully that will help it out a bit

[MyckMcClung]

for the money, a torque spacer from Moose. will do the trick. or a Gnarly pipe from  FMF, the Vforce3 also adds a bit of bottom as well as boosts power and smooths it through out the entire range.