We now only fit new carbs as a whole....we introduced this when the e5 came out and were inundated with nonstarting machines not run dry whilst laid up. This got worse when the e10 came out in 2021. It actually works out proportionally cheaper for the customer to fit a new carb (obviously once we have established it is a carb issue) than it would be to remove it, us fit a diaphragm and gasket kit, then re fit, and find there are still running issues with it. We are potentially doing the job at least twice. I get it from a hobbyists point of view where time and labour are not an issue, but if i said to a customer it will be an hours labour plus a kit to overhaul your carb, and once re-fitted there still could be an issue, so you will have to pay again for us to remove it again compared to just over half an hours labour to fit a new, known working carb so it is right first time. Instead of take old carb off, re build it, put it back on, still issues so remove it again is a lot more labour than simply fitting a new carb first time. Labour for us is £44 per hour plus vat...so labour to fit a new carb and set it up will be around £25 plus the carb. Potentially an hour and a half or more faffing around with the old carb could easily be £60 odd quid and yiu still have an old unknown carb fitted. So £100 to fit a new genuine stihl carb with a warranty or £60 quid labour plus a carb kit and no guarantees another issue may soon arise. Extra £30 or £40 for piece of mind and warranty is worth it...not just for the customer, but also us as a company as 'come back jobs we don't earn on.
I am quite happy to explain this and never had a customer since ethanol state he wants us to re build a carb.
There's your answer why we don't re build anymore spud.