I have one of the first fg60r3 and it was on the shelve all these years project took a little longer then expected . The mods i will do is placing a 0.5mm gasket under the cilinders to lower compression and I ordered the mmm timing ring. I hope these adjustment will keep it from cracking cilinders. Futerhermore i am going to do the JieM intake mod. I really love this engine on my byron at6 and i am contemplating to buy another one for an ugly stick.
And about the cracking of the cilinders. I have an saito fg21 petrol that also cracked the cilinder after about 25l of fuel so not only the 60r3 had this issue.