Your fixed cam face is toast, 'cannot be fixed', wear buttons are replaceable (only 3 of the 6 are used, so you can swap the worn ones with the non-worn ones- tap into place with a rubber mallet with thread locker to keep them from flying out). If you were on a budget, you would need to get a new fixed cam face ($15), and a new spring for the driven possibly.... but you might end up digging into everything and finding out more and more things are messed up... (drive unit typically has the most problems).... but its up to you if you want to replace the whole unit, or just get a new fixed cam face for the driven unit.
I'd go with the 30 series if i were going to replace it, as it is better all around than the 20 series, and will not have this big pully alignment problem. Can get on ebay here:
http://www.ebay.com/itm/COMET-TORQU...618504?hash=item5423027d08:g:RbMAAMXQTT9Ru8dN
Since this is a replacement motor, you can just swap out the drive and driven unit, and possibly the bearings that come in the kit, or just bolt on everything to the side cover with the kit....,
The original motor had a longer crankshaft. Not a big deal, but you probably wont be able to space out the original 20 series drive unit enough since the driven unit needs to run like it does (30 series runs reverse of what you have set up, so less issues with spacing on a shorter crank). Personally, if it were me, Id just buy one of those chinese 30 series torque converters for about $100, on ebay, then ditch the belt, and get a genuine comet belt.
You will need to measure the center to center distance (center of crank to center of jackshaft) to figure out what size belt you will need if you are wanting to keep your existing jackshaft setup, then reference a (google comet belt chart) 30 series belt chart, then get on ebay and buy only genuine comet, you will regret saving $8 on a knocko-off chinese belt.
Cheap mods that would give you the best bang for your buck include:
1) remove governor, and install direct throttle kit
2) high flow intake/exhaust/jet. ~$80
here, just a simple bolt on deal, really slick and will keep you from running lean, and lets the engine breathe in and out much easier so you will gain extra hp, and will handle other future upgrades to the internals.
everything else is super expensive after that. (billet rod/flywheel/cam/springs/machine work/porting/polishing.
I only made one for the 40 series unit, inot the 20/30 series, but has some good parallels though, clean metal with a brass wire brush, polish the sheaves, if sheaves are rusty, wire wheel. The driven unit is about the same, but drive untits are totally different. The right video is here from blazkoweiz
https://www.youtube.com/watch?v=C9yPHtfJO9w
Ps now that i think of it, i actually have a rusty 20 series driven unit on an old frame in my backyard. You can have it for the cost of shipping, and might be able to salvage the fixed cam face.
Good luck.
