Honda BF35A-BF45A Outboard Motors Shop Manual., Page 287Get this manual
Engine speed does not increase Faulty Automatic SE valveThrottle cable misadjusted
Replace: P5-15 and 21 Readjust (see base shop manual)Replace with the correct propeller
Clean and adjust or replace (See base shop manual)
Clogged fuel filterWater or depsits in carburetor
Replace (see base shop manual)Drain the carburetorIf it is still no good, overhaul the carburetor: P5-15 thru5-24Reinstall the timing belt (see base shop manual)