[raptorshtr]

i was thinking about cutting my carb spring a 1/2 inch, is it going to do anything or am i just hacking up my nice bike??

 

[got2b1st]

It allows the slide to open sooner, and while your at it drill the two holes in the slide out to the next size bigger.

 

[sport]

Curious where you got that idea from and if there is any documented benefits. I've heard of this being done on street bikes. Thanks!

 

[bassman]

This is a first for me, is it a good idea?

 

[got2b1st]

Einstein told me it would work! LOL. Actually this technique is nothing new since its been done in the automotive field for more years than I would like to remember(just reminds me of me age). The old Quadrajet carbs with vacum operated secondaries had an adjustable spring to regulate how fast the butterfly would open and Holley vacum operated carbs had different tension spings you could buy to install in the diaphram to tune the secondary. Its really old school technology.
Must be the younger generation is lost if its not fuel injected.Ha ha ha!

The Old Man!!!!

 

[bassman]

OK, I will give it a try, does anyone know what size drill bit should be used to drill out the 2 holes?

 

[got2b1st]

Off the top of my head I don't remember the size for sure but if you have a drill set in 32nds, find the bit that fits the stock holes and go the next size larger.

 

[bassman]

Do you think you will need to rejet after drilling out the 2 holes? anyone??

 

[shiftinraptors]

I cut my carb spring about 6 coils shorter. Just that did not seem to make much of a difference, at least not for the worse, but I can't tell if it's for the better. It didn't hurt it anyways. Where are the 2 holes to drill out to the next size bigger? I don't know where they are. Thanks

brian

 

[bassman]

if you remove your slide and look at the bottom of the slide you will see the holes on either side of the needle. I did this mod and my front end comes up much more. its a lot more like my 400ex than my stock predator. I like bringing the front end up as I come over the crest of hills so It was a good mod for me.