I cut 11 coils off on the Rancher AT.
I just got a video of my stepson riding a wheelie on it yesterday. He stood it on its rack.

 

Well, will this work on an '05 Rubicon?

 

Yes it will work on a rubi...and any other cv carb.
The posible side effect of going too far, is there will be a bog, if you nail the throttle at low rpm. Same thing on street carbs which have lighter springs in the diaphram of the vacumn secondary. Thats how youll know if you went too far.
The hole in the carb piston is balanced to the spring by the engineers at the factory, and there is a bit of leaway, on how much lighter the spring can be made, before the drivability sympoms show up.
Just remember, these are utes, and no matter how much you do..they are still tuned for low end,( mostly cam shaft) and not top rpm screaming.
And as was said earilier, on a cv carb, the slide is moved by vacumn...not the thumb throttle lever, just like a vacumn operated secondary, on street 4 bbl carbs.

 

I think I am going to start selling clipped springs to the people that are afraid to cut their own. I bet I could sell a ton if I market it right.

 

OK, I got up the nerve yesterday to clip the spring (8 coils) on my '05 Rubicon. It is definitely more responsive, however I still have the problem of it dying when I nail the throttle to wide open. I know others, on here, have the same problem, has anyone fixed it?

 

This mod work on a shee or is a utility quad only thing?

 

It only works on CV type carbs.

 

i think the z400 may have a cv carb..

 

sporter. Give me a little more info on your problem. Does it just stall when you nail it from stopped or from a roll? Is it bogging? When just putting around barely touching the gas, does it feel like its loading up? By loading up I mean stumbling maybe popping? It is probably your mixture is a little rich. Theres a screw on the bottom of your carb. Its a slotted screw. Take and turn this clockwise until it seats. Counting how many times you turn it. If it was 3 times in bring it back out to 2 1/2 turns. Then ride it a little to clean the plug. Then nail it. See how it feels. Do you have any aftermarket parts on it? Like a K/N? You may have to try this adjustment a couple of times to get it right. But only move the screw 1/4 turns at a time.

 

Rinman,
It stalls when I nail it from a dead stop. I haven't noticed it loading up while riding. I will try the mixture adjustment this weekend. Appreciate your advice.