2009 Yamaha F40 Outboard Service Manual, Page 47Get this manual
Electronic control system
Variable trolling speed control
The Multifunction tiller handle model or the Command link Multifunction Meter (Tachometer) allows the trolling speed to be adjusted within certain rangeControl range Revolutions per step 650900 rmin 50 rmin
The trolling speed can be adjusted when shifting to the trolling mode by turning on the switch on the tiller handle or operating the mode button aFor details of the operation of the mode button, see "OWNER'S MANUAL The engine ECM changes the target engine speed in accordance with the switch operation, and then moves the ISC valveThe variable trolling mode will be canceled when the engine speed exceeds the limit after opening the throttleTrolling mode canceled at 3000 rmin Multifunction tiller handle model Throttle body ISC valve