carb vacuum slide

I read where cutting a inch off the vacuum slide spring helped acceleration, how does that help and has anyone tried it? Thanks

Dont do this unless you want to be looking for another carb spring.

mudandguts said he did this to his 450. I haven't tried it.

Well go out and cut yours and let me know

Get a Dyno-Jet kit ,it comes with a less-resistant spring. I would not cut the stock spring.

I cut the stock spring and ran it for a while it worked fine for me and many others. It allows the carb to open up quicker and accelerate slightly faster. I got the dyno-jet kit and run that spring now which is about the same in tension and size as the stocker cut.

Thanks

Cutting this spring is something I have done a lot of research on (before cutting my own) I was skeptical at first but after talking with several racers and engine builders who use this trick I decided to try it myself. I ordered an extra spring from Yamaha the first time I did it just in case (they are cheap just a couple bucks).
It would get real expensive for an engine builder to order a jet kit for each bike they work on when instead of buying a dyno-jet jet kit they keep mikuni jets and shims in the shop for jetting and shimming the needle and cut the spring instead of paying 50$ for one that does the same thing.

I cut 3/4 off mine yesterday very happy and no flutter at wot

I cut 3/4 of a inch off

easttnrhino wrote:

I cut 3/4 off mine yesterday very happy and no flutter at wot

How do you feel the engine response is from this Mod?

The throttle respone is quicker but I would only say a small amount but price of the mod is good