transfer game save of forza4 to another xbox

You need a data transfer cable.  I bought mine a while back when I up graded to a bigger hard drive.  Actually, it came with it.  You can probably find what you're looking for at your local Gamestop or Best Buy.  I got mine at Circuit City which has long since gone out of business.

I believe you can "Move" the file with a USB drive. However, like you have found out, the file cannot be "Copied." As Strunky stated, the transfer cable also works very well if you have a lot of data to transfer.

^^^^^^

I did that just to get the kinect achievements and lost a few unicorns in the process. Completely my fault, i could have kicked myself for not reading the warning message about 'content missing, some cars are going to be removed from your garage if you continue'

if you play forza quite a bit and have DLC as well, i would just leave it on the one console.

There is one file that you can only transfer with a transfer cable. If you do not use a transfer cable you will lose stuff. I have been through this myself.

No other game that I know of presents this much trouble when trying to move game saves...and it's all because of their stupid fake in-game economy that they're so worried about people glitching credits in.  So in an attempt to stop the cheaters, they make it annoying and cumbersome for legitimate users...and the cheaters still find a way...and everyone loses.

tonkacrash.wordpress.com/.../moving-game-saves-and-multiple-consoles-revisited

Well still have my cars in the club but bye bye all the work for level 104 thanks turn 10

I know losing your level sucks but at least you have all the REAL work you did.  Levelling in Forza is really a matter of time not skill so try not to think of it as work.  It's a labor of love.  As long as you have your tunes and paints you still have your basic identity in Forza.  Afterall, it's your cars that are of real value to you in this game.  

I dunno why they changed the 150 level limit. Does getting to 999 mean prestige mode? lol. I've played since release and still only like level 128-9.

Meh, levels mean nothing in this game.  It mearly reflects how much time you've devoted to racing.  I wouldn't call it a measure of skill at all.  Although it could be argued that the more experience you have the better you should be.