20hp tohatsu stalls with low revs

[jonathanteller]

20hp 4 stroke tohatsu stalls with low revs. Runs fine with 50% throttle or above. It will only idle with choke on.
The carb is 18 months old and I just took it completely apart and gave it a thorough clean. It was already spotlessly clean. this made no difference. motor is 5 years old.

 

[pvanv]

What is your actual Model? What method did you use to clean the carb? It is clearly way too lean, so probably need to clean the carb Properly. Make sure the base gaskets (on each side of the plastic thermal spacer) are good.