Thanks for all the info guys, that helps a lot!
I found this Tomar clutch for the KTM 50 SX 01-08, which is a wet clutch. I know their regular centrifugal clutches for those models have the correct taper for an e50 crank so I assume this Tomar would work on an e50 crank without modification?
Tomar Clutch KTM 50
From what I understand, the bell that's included with that would just need its gear pressed out, and another pressed in. I have one thats already bored with a needle bearing, so would just need to transfer it over to the Tomar bell, right? Todd you mention clearances, is this if you try to use the clutch with a different bell or with the included bell?
My current setup is a V1 bell/needle bearing and a KTM 50 centrifugal clutch (with pull start). And polini 64 kit + 15mm bing (soon to be 24mm OKO along with some intake porting), sidebleed estoril, HPI cdi. It's been very reliable, besides the clutch issues.
The "KTM clutch" I have is a chinese knock off hub with real KTM shoes. The springs I got were a little too stiff so I've been experimenting with different springs/washers but have not had great luck. Those chinese hubs SUCK! I think the poor tolerances caused the shoes to not really lock into the hub snugly and they apparently banged around and damaged the shoes. The hubs also crack if you torque the retaining bolts too much (IE even the slightest amount of torque in this case).
Looking into real KTM hubs and shoes as a replacement, the price equals to about the same as that Tomar clutch, thus shifting my interest into maybe using those instead. It would be mostly for street use, though. But with how traffic drives around here, I need something that is a bit more aggressive than how the KTM one is performing, and something more consistent/reliable. I miss the trickmetric/treatmetric ones.. but had terrible luck with springs breaking on those constantly, even after chamfering the holes. So that caused one of those shoes to get damaged thus kind of leaving me without either clutch setup being usable at the moment.
I've seen a lot of back-and-forth on using straight cut vs helical, I am only around 150lbs so dunno if its not as much an issue for me but would definitely be interested if I can get the cash for that setup!(edited)