RE: FUntana 90 and karbonite servos?
We don't suggest using the Karbonites in large gas powered models as a rule. We've found the demands are far greater than the Karbonite can handle. On the same note there many modelers using them in multiples or pairs on 33-40% models without issue.
The Karbonites are not replacements for metal geared servos, if the manufacturer of your model suggests metal geared servos I would abide by their recommendations.
I'd suggest exchanging the servos for metal geared units.