Rotax 912 Hot Start Issue

Please click on this link and read - https://www.rotax-owner.com/en/flightsafety/476-ai476 This should provide you with some good info on the issue you are experiencing. 

Since I've had the issue I've had the carbs refurbished where the old (good) floats were replaced with the famous sinking floats. Last summer I had a sinking float and replaced both sets with some new ones (apparently fixed) under the recall scheme.

I don't think the floats were the issue as I've has the issue with all three sets of floats.

I will weigh the current set again as part of the next service.