56 is perfect for the rear. you can change out the front from stock to -1 at will without breaking the chain or anything.
i just put the stock back on the front a week ago, but i think i might go back to the down -1...its a noticable difference.

 

Interesting. Def get a second idle cable. That helped me a lot!!

 

Also, i hear that low low gearing helps with the f4i. -2 in the front helps a bunch and a 60 to 66 rear helps.

 

I run 14 up front and 64 on rear and I love it on my f4i!

 

The weather was fantastic, bright sunshine, a gentle breeze rolling through the valley to keep you cool and a dry and slightly dusty MX training track along with a great little burger bar that does actually do quality burgers!! With our bellies full Team LFB hit the track which for most of the day had no more than 10 riders on it at any one time.




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Kerastase
Kerastase Reflection

 

you MUST run two idle cables on f4i's

the stock idle cable adjusts your low end FUEL MIXTURE.. If you turn it up to turn your idle up, you are messing up your fuel mixture, and it wont be right at bottom end...

The second idle cable you install so it opens your butterflys on your TB's just like the throttle cable opens the butterflys....

If you remove the stock cable to hook it up to the butterflys, then your low rpm fuel mixture will be off..

you MUST RUN BOTH!

 

yeah i have the second adle cable but i rarely use it.. guess i should play with that a little first. I had a 56 rear , stock front. Put a 60 rear and a -1 front about 2 months ago and i love it. But fudge it, you all are making me want my 636 back. maybe i wont fix anything and ill just sell it

 

I have 32K on my f4i and it pulls like a champ but i have 15 front 71 rear. Did the second idle screw mod didnt any diff. But i am running a power comander..

 

i have the same bog problem with the 03 636 only when your going slow