ok you cut the spring 4 or 5 coils and enlarge the holes to 1/8 in the slide... is that it?
my buddies keep telling me i am stupid for wanting to do this.. they say it adds nothing... well i want to prove em wrong.. what gains did you notice.. better response? anything else?

 

Be carefull not to cut the spring any shorter than 3 inches.
Some guys get cared away and then complain that their running too rich at bottom.
The drilling of the 2 vacuum ports to 1/8 helps if you are using a direct mount filter.

 

i do have a clamp on.. any shorter than 3 inches.. how many coils off would that be..
what can go wrong when i drill the wholes out.. i mean.. like if it doesnt run right?
cutting the coils adds response right?

 

Drilling the holes increases negative pressure in the bladder, thus the slide goes up faster.
The slide also comes down faster. This change is minor, but every little bit helps. Will not make your quad run worst. Cutting spring is different. If you go shorter than 3 inches, the slide will have no support at idle. Slide will bounce and act like a accelerator pump, and the low end will be rich.
Mikuni uses 2 springs and even though they have the same pressures, they are different lengths.
Not knowing which one you have I then recommend you cut your spring to a overall length of 3 inches.
No shorter.
Bottem end response will be better. For dragging its great.
Remember that any changes to a carb may require fine tunig your jetting.
Once dialed in you'll never go back to stock.

 

Yeah..just cut 3-5 coils off the spring...

 

fine tuning?
k just the MJ right... ill prolly hafta go up 1 size?

 

Main jet will not need to be changed, if dialed in now.
What you may have to change is your jet needle height.
As vacuum signal is increased , you may find your mid range different.
With motor warmed up, in 2nd gear, about 3000rpm, hit throttle wide open.
If motor accelerates but not hard, is too rich, lower needle.
If motor falls on face(boogs) and then hits very hard, too lean, raise needle.
If motor hits good and accelerates hard, you got it just right.

 

could i just cut the spring or does it not make much difference by itself.. i just dont like the idea of drilling my carb slide.. its 50 bucks to replace. the spring is 4.99$

 

cut 4 coils, and drill them holes. Drilling the holes is very easy I was alittle hesitant also but it was very simple, I actually drilled mine to 7/64 which is 1/32 bigger instead of 1/8.

Right now with a hmf pipe and clamp on I am running 170 main, raised needle one notch, 50 pilot and 23/4 out on the fuel screw. Seems to be just about spot on here at 1000 ft.

 

Cut and drill it is not a big deal. You will see when you start you are not enlarging it that much. I took 4 coils off of mine. Just remember to put the cut portion of the coil on the cap side and not the slide because over time the sharp edge of the cut spring <u>might</u> ruin the slide. I also cut my airbox in half and have noticed a big difference in runablity and performance over the clamp on however I was running a UNI clamp on and now I am using the K&N replacement in what is left of the airbox. Check ot the pic of the airbox mod in my bio.