Difficult cold start

I can't help you with not believing me, but the story seems to be changing. We can't see or hear anything you claim. All we have are your words. What was a "difficult" start at 10 Celsius is now "massive" at 30 Celsius. What was running and idling "great" warm is now suspected of having ignition and carb problems, but again, those areas can be improved by a mechanic.