I am currently looking into getting some aftermarket tires and i am having the most difficult time trying to figure out what the biggest i can put on my cforce 600 2019 that i don't have to adjust the clutch, won't weight me down, and i won't have to trim the fenders and won't rub. Anyone put bigger tires on one or know if i can put 30 in on it or i'm thinking at least 27 or 28 in. Any information would help. Thank you in advance.

27 or 28 i think is about max if you don't want to trim fenders and adjust your clutch. Clutch adjustment may be needed on 28" depending on tire weight.

I'm currently running 27x10 front and 27x12 rear ITP Mud Lyte's on aftermarket 14" wheels on my C600.  No clutch work, trimming, etc... has been done.  Runs great and no scrubbing.  The smallest gap is between the front of the rear tire and the bottom of the rear fender.  But still plenty of clearance. 

I'm currently running 27x10 front and 27x12 rear ITP Mud Lyte's on aftermarket 14" wheels on my C600.  No clutch work, trimming, etc... has been done.  Runs great and no scrubbing.  The smallest gap is between the front of the rear tire and the bottom of the rear fender.  But still plenty of clearance.

Any Idea on what back-spacing we need, I'm seeing 4:3 and 5:2 not sure which to select if anyone can help please.... Looking to run 14" wheels with 27x9x14 and 27x11x14 set-up

Dealership in NC or SC or thereabouts makes all sorts of videos on CFMoto stuff.  Most is about CForce 500-600-800-1000 and modifications.

In short, 27" tires will fit 500-600 without rubbing.  If you get heavier tires, go bigger, you will need 1.5" (or more) wheel spacers, and possibly a lift kit.

Heavier tires may require clutch mod depending upon what you want to achieve.  They install AIRDAM clutch kits, and it is really not difficult to do.  If you are reatively handy, have some tools and can improvise the long compression rod (use .5" or ,625" threaded stock) you can do the clutch thing yourself.  There are many videos on YTube showing how to do it.

I have no idea how much $$ AIRDAM kits are.  The AIRDAM kits are multiple-- meaning many different setups for what different people want to achieve. Example, you can get better power in high end for more speed, or better low end grunt for doing slow stuff (like snowplowing in L), and so on.

YMMV