ORIGINAL: YOGA FLY

HELLO DL Brothers . I just got me a brand new DL50 and i need some advice.
The plug threads have a lot of play \ slop even one turn out from full tight so do i worry or just tighten and forget about it . There is a small (half inch) size 3 coil spring can some one tell me where does it go.. I plan on using a slimline invert pitts muffler ment for a DA will it work good or will it rob power. Thanks to all who gives advice.