400ex thumb throttle pushes hard

[bry14661]

Ive tried lube down the cable and on the axis in the carb but it still pushes hard enough to cramp my thumb so bad in a XC race i find myself reaching over the top with my index finger and middle finger pulling the throttle lol. Anybody know a way to lighten up the pull on the throttle without a thumb buddy. Not a fan of having it in my palm while hitting large bumps. It pushes way harder than my 450r

[sprayedgt]

I don't know. That's weird yours is hard to push. A 400ex's throttle are about the easiest to use. I know a lot of Yamaha owners use 400ex throttles because they are so easy to push. Could it be possible that the cable is frayed somewhere along its length and dragging on the sheathing?

[bobkunkle]

I've heard of some people changing the thumb lever out for one from a TRX90. The TRX90's lever is longer.

[bry14661]

i guess the cable could be fraying along the line somewhere. Not sure. seems to move easy with both ends disconnected. Im about to put on the 450r carb. Does that make it any easier?

[bbender85]

in the 450r carb research i've done, everyone says even if you dont gain any power (which won't be the case), the easier throttle pull is worth the conversion alone. i have a 450r carb waiting to go on, so i can't speak from experience quite yet. my 400 is real hard to pull tho, too, riding MX tracks.

[sc400ex_rider]

yes the stock 400ex throttle is very stiff stock. what i did was take the cover off the handlebar lever and take the little spring out. next you take the carb off then take the black side cover off the carb. find the spring that is on the throttle plate shaft. find the little bent tab on the spring that holds it on. only on the carb side not the cable side. then take a long strait tip screwdriver and pry the tab away from the carb letting it spring around one whole turn. this makes a world of difference. also if you get a 450r carb the spring is not as stiff at all.