My 12 year old Stihl FS90 has been having issues starting from hot lately. Starting from cold is fine, and once running it has been fine. Given its age, that it had never had anything other than filters and spark plugs before, I dropped it off at the dealer it was purchased from to have them service it.
I got a call from them today to say it was ready to pickup, and that because it had an aftermarket carb on it that wasn't adjustable they had had to replace it, and that the total damage was $128. They didn't call to talk about what it needed first, they just went ahead and did the work. This is a unit purchased new from them that had never been touched by any other shop, and that I had just done periodic filters and spark plug replacements on.
Assuming that it's not a mixup in their paperwork, it seems they're either lying about the aftermarket carb (likely), or admitting they sold a new FS90 with an aftermarket carb fitted (unlikely). How would you approach this? Assuming it now runs and starts good, and that it may have needed a new carb anyway it may not be a bad deal for dealer pricing... but the deceit kinda bothers me. Should I burn my relationship with the dealer to make a point, or just eat this and go to another dealer in the future?