I know it might have been asked before
But is there any way we can get a different
Or a substitute for fl350 piston ?
Surely there is one out there besides weisco
I think there are junk .

Nope on substitute
Yup on junk - my opinion LOL

I don't know of any but I really have not looked now might be a good time to start researching and find another OEM piston that will fit in its place, its a 18mm piston pin, 80 to 82mm.

I wish we had a inside guy/ friend that worked at ART http://www.art-piston.com.tw/ http://www.art-piston.co.jp/en/piston.htm who could run us a batch to the OEM spec, since we don't and proX has ART do their pistons maybe someone knows someone in the ProX world that can have them run a batch?

Years ago SUDCO use to have ART make their pistons too http://www.sudco.com/art.html

called hillside honda they said the fl350 piston is kinda of a bastard child. He didnt know of any other piston that would fit. I have a hard time believing that. I am going to do a little more digging on it. Like I said the current weisco piston sucks and is a
piece of shit along with the rings . I am thinking about selling all my 350 engines and parts before I put another one of those fishing weights into one of my engines. and go with a a sled Engine. By the time you go through the whole bore and keep throwing one of these slugs into the bore in piston cost alone 80 80.5 81 81.5 82 that is 1000 dollers. so if you can get 1 good full riding season per bore 5 seasons its done . How long have the rotax engines been going without a rebuild?

I too have been having a real hard time with my fl350 engines but I have learned a lot.
One thing I learned just recently was that because the fl350 has a steel liner you have to keep some heat in it to keep the piston from growing into the sleeve. I found this out the hard way when I water cooled both the oddys. The temp never went over 120'F and that was way to cold. When the Engine seized the piston had scuff marks all the way around and this had never happened in any previous poofkaboom. The other issue was detonation. Blew holes in several pistons. The gas up here in Canada must be total shit. I now run AVGAS or 50/50 AVGAS and premium. So far so good.
In other words I don't like Wiseco but not all poofkabooms are piston related. Just my opinion.
Every time I get a new Wiseco the rings have excessive gap right out of the box. If we could find another piston manufacturer I would buy from them for sure.