Morse control creeps down

[Harold the Sailor]

Twin station twin engineLehman 120s. Throttles creep back to 1500 rpm when set at 1850-1900 rpm, glendenning synchronizer, I tried the clutch adj on the synchronizer, no help. 1982 Uniflite 37' any ideas?

 

[makomark]

which engine is the master (aka Lead) engine? is its throttle setting consistent? The synchronizer has no control over it and will adjust the 'slave' rpm to 'match' the master's...