Not a very common issue on walbro carbs but it does happen. When the butterfly fastening screw becomes loose, and with vibration whilst the engine is running, the soft brass butterfly is able to move laterally and the edges end up being damaged against the aluminium carb barrel. the result is an air leak which will mean you wont get a low enough idle anymore. If you can source just the butterfly its an easy fix. Alternatively it requires a new carb. At AerobtaX.co.uk we carry all GP spares including replacement carbs for all engines. Thanks for watching!
Aerobatx Ltd UK
Walbro Carb - High idle problems solved
