So when i got the bike, the chain was loose. Had like 3-4" of slack while on side stand.

I was going to tighten it, but there was no adj room left. Ordered a new gear and chain set....
finnaly got around to do it.
was VERY easy, and theres a few hiccups in here i need wisdom upon....
someone stripped the nut that holds the front pinion gear on the shaft, but the shaft had really good clean threads so it appeared that some person has drilled the threads out of the m24x1.50 nut and used it as a spacer and the little washer and bolt that go into the end of the transmission output shaft (mabey a m8x1.00) was the only thing holding on the pinion.
long story short, got new hardware and resolved the issue..
i went on a test ride and couldnt belive the difference....so so smooth and quiet. But someone had geared it with a 13t pinion @nd 47t rear sprocket.. My new aet has a 15 by48t ratio... Bringing my 60mph in 6th gear rpm from 7000rpm to 4500.


acceleration lost a little but still wicked fast.
 theres where i wanted an answer about wheel adjustment.
i went by the marker on the swing arm but the little marker brackets had a little wiggle room so i tried sliding the little bit toward thw rear on both sides.
anyway, got it all set up and aligned but wanted to know of a good way to insure exact allignment... Like measure fro swin arm to edge or rim on both sides mabey....or what? Its pretty dang straight but want oit to be dead on... Any good methods to double check? I dont trust the little sheetmetal guages that were on it.

While it's probably not the most professional thing, I have always just used the marks on the swingarm to align the rear wheel.

I go by the marks on the swing arm as well. When you loosen everything there's a bit of play, but under tension things don't move around as much. I also count the rotations of the bolt since you can trust the thread pitch.

According to the manuals I've read, you should use the marks as a guide but also sight along the chain, the rear sprocket should be perfectly in line with the chain, not twisting off to one side.

I get the feeling that there are a number of things (like tire alignment and wheel balancing) where you need to get it close enough, but not necessarily 100% perfect. If the alignment is off by a fraction of a degree, you might never notice it, or not until you're near the bikes top speed. So get it as close as is feasible, but don't sweat it unless the bike doesn't feel right when you're riding it. 

How the bike feels is the ultimate source of truth, because manuals can be confusing, misleading, or just plain wrong.

well I checked it with some of my Machining tools set up jigs and some laser line sites and stuff like that and I couldn't find any variation but it drives like a brand new bike now so if trusting way the bike feels it's the way to go then I'm on the money

The old Russian proverb "trust but verify" applies here, IMO.

Use the markers on the swingarm, but then apply the "calibrated eyeball" to it to make sure that the sprockets appear to be mostly in line with one another.