There is a shoulder inside the left fitting, you bolt that one in place, slide the cross tube in place then thread the inlet side in until it's snug and tighten the nut on the outside, get yourself some real o rings for the bolt and the nut side instead of the thread type "o rings".

The tensioner is on the return from the generator to the flywheel side right? Belts should never be banjo wire tight.

Simple minded farmer my a$$, one that grows all his own oil crops for fuel then presses his own oil and makes it into bio diesel, simple minded..............

You guys didn't really hold hands did ya?

If your belt won't run on the naked flywheel your generator needs to be moved around a little you should be able to adjust it enough so the belt runs on the flywheel in the center, the flywheels typically appear to wobble in the verticle plane because they are not machined on the sides, that aspect usually means nothing in terms of balance.

Yeah but it was "Tested".

They don't look 24" dia or heavy enough but look at them beautiful flywheels!  http://www.youtube.com/watch?v=MpmuZwdlPrc

Mostly it depends on how much they have been run and how good the compression is, but if you get temps of 20's during the day and 10's at night you will need help.
I took the air filter off rotated the flywheel till the valves were at the overlap point and blew a bottle torch in the intake, it don't take long.