I have a couple G90's. They were Italian made before the factory shut down. Had them close to six years.

They both came with the Super Tiger 40,46, & 51 carb. One of them has about a gallon and a half through it.

15% Rich's brew fuel, mid 30's temp, 1,000 ft elevation, APC 14-6
W/ the 40,45,51 round sided spray bar carb 10,000 rpm
W/ the 61,75,90 carb spray bar installed in the carb body -- 10,500
W/ the ASP old style 91/108 carb 11,000

I ran a 15-8 on it some but don't remember the rpm but I think was around 8400. The engine didn't over heat but had a slow spool up.

Dave Gierke from Model Airplane News contends that their toque peak is below 8,000 and you should run a big prop like the 15-8.

I like the MAS and APC 14-6 on them myself