Merc/Mariner 50hp 4 stroke pwr trim

BillP · #1 October 27th, 2003, 05:28 AM

My 1996 Mariner 50 4 stroke's pwr trim automatically drops down at 1200 rpms. Been doing it since new but I never worried about it until now. The motor's manual says it is supposed to drop down at 2000 rpms. Does anyone know how to adjust this or what the problem is? My Clymer's manual says nothing. It's on a pontoon boat so in high headwinds and shallow water it could use the extra 800 rpms with the motor tilted up.

Bill

The Marine Doctor · #2 October 27th, 2003, 06:10 AM

This is regulated by valves in the trim pump itself. You probably have a weak valve.

TMD

BillP · #3 October 27th, 2003, 04:37 PM

Thanks for the info. I'll check the manual and try to ID the valves. Too bad I didn't do anything about it during the warranty period. It hasn't changed since new so I though it might have been setup wrong at the factory.