DF15 - Recurring problem no one can solve! High to low revs issue

[Chrisg149]

I’ve taken my Suzuki DF15 outboard to three different marine mechanics over the past 5 years; but not one can solve the problem. After about 30 minutes on higher revs, when I reduce to low it hunts, splutters and eventually stalls. It’s been serviced, fuel tanks cleaned, carb cleaned etc by experts, but to no avail. Here is a link showing the problem

The problem only occurs when the engine has been running for about half an hour. Can this forum solve the unsolvable problem please?

 

[racerone]

Saltwater ?-----Was water pump impeller replaced ?

 

[Chrisg149]

Actually inland fresh water rivers. And parts were replaced a few years back. Thanks nevertheless for the suggestion and hope more ideas come along. Chris

 

[racerone]

Find a good shop.----Your location ?

 

[Chrisg149]

Could visit Suzuki dealer on Norfolk Broads, UK.