Fuel issue on stroked kx125cc engine

[CRGkx125ivan]

Hello, I have a 09 CRG shifter kart that has a kawasaki kx125 engine that has been strowed to 144cc I believe.
Under full acceleration I have zero issues but when I come to a corner, and resume acceleration in the correct gear, the engine will not accelerate, feels like it's still running but doesn't have any extra fuel to get moving again.
I play with the throttle a bit and then it resumes, like the power comes all at once and then I have the issued all over at the next corner. I have a small rectangular fuel pump and one of the gentlemen at the track suggested to change it to a round larger fuel pump.
May also be carburetor issues.
Please let me hear your suggestions.

Thank you.

 

[Flyinhillbilly]

It kind of sounds like it's too rich to me. Is it kind of stuttering when it won't pull? Usually lean on a two stroke makes them real zingy. I've blown up a lot of two strokes pushing for that extra zing.

 

[anderkart]

with Flyinhillbilly

Under full acceleration I have zero issues

CRGkx125ivan,
This fact kinda makes me wonder if the problem is the total opposite of what your assuming. It could be that your carb is actually flooding in the corners, not starving the engine.

An super easy test you could try to help diagnose things is to pull the choke part way on (or maybe even all the way on) as your cornering:

If pulling the choke helps the problem, that means you have a fuel starvation issue and the large round Mikuni pulse pump might be your solution.

But If pulling the choke on (even just a little bit on) makes the problem even worse, that means your cornering problem is being caused by flooding, (not starvation) and one possible solution would be setting the correct float-level in your carb.


Another common solution for shifterkart flooding issues is to purchase/instal the special needle and seat valve that Mikuni sells for their carbs when a fuel pump is being used. (the stock needle and seat valve that came with a KX125 would have been intended for a gravity-flow fuel system, not the higher pressure of a pulse pump...)