The flywheels that i do (in the picy) are simply 2nd hand "2 piece" flywheels that have been CNC machined to exacting specs,,, in otherwords---> if the flywheel that we have to start with is pretty well balanced , then it will be pretty dam close to being in the same dynamic as when it started.
I would however recomend that you balance all reciprocating mass when building an engine anyways, so after whatever mods you do to you engine,,, whatever you add to the stuff that spins/turns/goes up & down/ round & round etc etc etc --->i would have balanced before you fit it,,,, just to make sure it`s not right out of whack,,,, most stock mini flywheels aren`t to bad actually,,, but in saying that, i have also seen some that needed massive masses taken off one or even 2 sides to get thenm closer to the mark
& no,,, they don`t come with a back plate at that price,,, crickey i`d have to be on some pretty dam good drugs to let a CNC machined lightened flywheel & back plate fully balanced to go on sale at $150 exchange,,,

would you like a new ring gear & the whole assyl balanced , with a new comp clutch plate & diaph & all fitted for that price while you wait too ???

kidding,,, definately kidding,,, my drugs are not "That" good
I used to do 5 or 10 at a time but cost heaps that way , so now days I do 20 of them at a time,,, i think i have 2 , maybe 3 left from the last batch atm
There are literally over 200 of them out there somewhere & only ever had one have a problem, & that was simply because the dork that fitted it had cocked the centre when he bolted it up to the flywheel & had some shuddering issues,,, my mmate Stew bought it off him for $10

we took the centre out, re-fitted it nice & squre so it sat flat whewre it was supposed to be & it works a treat

easy-peasy,,, not one othe rproblem with any others at all & i did my first one when i was 16 years old,,, now i`ve only just turned 365 years old

till just a young pup really hey?
