Been working on my Zen porting as per Scotts article and have the cylinder and crank case done.My next step is the crank turbo mod.I know only to shape the outside leading edge.I don't want to take off too much but also don't want to take off too little.Will the crank be out of balance? Any advice?

The turbo mod is NOT a mod done for increases in power, it just helps in preventing case pooling of fuel, directs the air displaced of lead edge into transfer flow and help better lube the main bearings.
* If you do the edge sharpening as shown the crank balance has never been an issue in well over 100 engines i have done personally.

If unsure about it ... don't

Thanks again Scott. I am gonna go for it. If I don't try I can't learn. I'm headed to my shop to let sparks fly! Have a good labor day!!