Halo 3 is alot like halo 2. There are some new weapons and alot of the ingame mechanics have been upgraded. You can take your allies weapons and etc......
I honestly think that at least half the 2 into 1 setups out there are not tuned properly. I attribute this to people not liking how it runs. Cause a properly tuned one will haul some balls.
Your chain will sound like its skipping in deep sand because the sand gets in between the sprocket and the chain. The chain will slack up then pull and snap like its skipping. Its normal.