Are the Hutzl engines and parts sold on Ebay any good ?
I will start by saying I am NOT unbiased, I sell a ton of OEM Stihl and aftermarket parts including Huztl.
Some parts sold by Huztl are identical to OEM, as in made from the same mold. If parts for a specific model were previously manufactured for Stihl in China but are not currently in production, their laws permit them to make them and sell them to anyone, minus the logo. Some parts are identical down to the embossed part numbers.
Do you need a replacement recoil assembly for an MS660? You can have it in two days in the US for less then $30 aftermarket or just the cover in two days from the dealer if you don't mind reusing all the guts and springs for $91.00. Hmmmmmmm
I will say that they have some products that are junk, most recently the MS660 standard bore piston comes to mind and the complete MS660 engine assembly. I am recalling all I have sold and replacing for free with MS660 Big Bore kits, which are much better, though still not OEM caliber, but at less than 25% of the price you have to decide on the better trade off for yourself. Huztl will reimburse me for the exchanges, in my dealings with them they have been reasonable and have even told me straight up when a product was junk if I happened to order it.
As far as I have experienced only the Meteor brand of pistons and cylinders approaches OEM quality. Watsonr here is a great vendor, I have purchased from him and been very happy.
All other manufacturers produce less power than OEM and the vast majority will be improved by Caber rings. Caber manufactures for many OEMS including our favorites at times
If you spend 25% of OEM on a new top end and another 10% on great rings and make 90%+ of the power of OEM you will probably be happy.
At the other place we have a pretty active thread on the continuing state of the aftermarket FWIW.
DDave
P.S. for what it is worth I ALWAYS let a potential customer know if the saw we are discussing has any aftermarket parts. It is simple fairness and simple math, if it costs less it is worth less.