360 Flywheel balance

[basement]

This post is a followup with a flywheel balance problem I had. I ended up pulling the new flywheel back out and had the balance matched to the original. The man at the shop said they had to remove 50grams from the new flywheel (not sure how much that is but he said it's alot). Now no more vibration    I've attached a pic of the flywheel after it was rebalance and circled the balance points in white. Moral of the story, when in dought have your flywheel checked before you end up waisting a bunch of time.

[rottenfish]

I missed your original post, but I have some experience on this topic that may or may not be relevant to your particular situation, but here it is anyway... Drilling the flywheel to "factory specs" (diameter/depth/orientation) often leads to vibration. I am unsure if this is because of operator or equipment, etc, but it rarely seems to work well. Here are two good ways to balance a neutral flywheel properly to factory spec:

1: Buy a counterbalanced flexplate (there are a couple companies that make them) and sandwich it between the flywheel and the crank. It sounds horrid, but there are very reliable accounts of this working, although I haven't tried it myself. There was some discussion about bolt lengths and starter shimming, but even without shimming the whole thing was reported work well.

-or-

2: Buy/borrow same said flexplate, sandwich it to the flywheel 180* out of phase, and have the machine shop balance the whole assembly to neutral. Once you pop the flexplate off, your flywheel will be balanced exactly to the "factory" spec. I have done this several times, and it works great, and is very easy for the shops to do. Same theory applies to any cast crank external balance engine.