fcr throttle spring mod

has anybody here done the throttle spring mod or done anything else to lighten the pull on the throttle. my carb is from a wr400,not sure if that makes a difference or not put it is incredibly heavy and tiring after a long ride. i already have brand new cables that are perfectly lubed so thats not an issue. i know you can buy aftermarket springs but why would keihin have such a heavy spring in the first place

that's not right...you may have some issue with linkages and wear....it shouldn't be, quote, "incredibly heavy"..

Does the throttle return briskly..?

Sticky throttle cable.

Clean it out and lube it up.

It may have a few frayed strands sticking out, then it's time to replace it.

the cables are brand new and perfectly lubed. throttle returns very quickly,when the fcr is out of the bike,to turn the throttle wheel requires so much force it hurts my fingers. its not sticky in any way,its just a really heavy spring. i have the standard carb in front of me now and at a rough guess i would say the fcr throttle wheel  requires twice as much force to turn as the standard carb

the throttle wheel out of the bike will feel heavy, the cables use a good mechanical advantage so its easy with the wrist.

The throttle probably has 2 return springs arranged in parallel.  You can remove the throttle wheel and remove 1 spring.  I some times do this on street bikes.

Is the throttle tube jammed up on anything?

If the tube is jammed, it'll be hard to turn.

Are your bark busters hitting the throttle tube?

The FCR MX carb is much heaver off the bike as you stated that is normal. You can do as Noble suggested also check your cable routing making sure there are no tight routing spots while turning from side to side. Normally I have left hand cramping after long rides from the stiff clutch, MAN UP and ride. 

I use a device called a throttle rocker.  It clips to the throttle grip so the heal of the hand helps to hold the throttle in position.  I use one on the street bike and the dual sport.  

i'll check everything again but like i said the pull on the throttle requires twice as much force as the original carb. i'm pulling the fcr out next week so will take some photos and see if i am missing anything

Hey Op any solution to this?

Thinking about it, you could have a binding cable. My stock cable wasn't aligned properly and caused it to wear out and snap. Also with the s cables, the pull cable with the curved housing needs to be properly aligned or it will bind on the sideways mount Fcr vs stock top mount s carb

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