Good idea..tnks

Am I missing something here?

If you swap the hoses on the pump, you will be using the Down circuit for the Up mode (I'm talking about the hydraulic circuit, not the electrical circuit). The Down circuit has a pressure bypass to allow the drive to kick up if it hits an obstacle. This same feature would let the drive slam down against the stop when you hammered the throttle. Wouldn't it ??

The pump used on the external style V6 Mercs and most I/)'s for a number of years had check valves accessible on either side of the pump body. You didn't have to take anything apart other than the big hex covers on each side and then swap the valves - too easy. (just make sure you put the drive down against the stop or you'll get oil shot across the bilge when you pull the up chack valve out as the drive drops by gravity).

10-4 mcollin

On the trim pump I have the hold valves are internal on the pump so you have to take the pump off the reservoir.Both valves are the same and they are adjustable to tailor to your needs.Usually when this sort of thing fails it is do to a damaged seat or dirt in the seat.The main purpose of these valves is to hold the load not relieve pressure.If you hit an underwater object the oil couldn't get up the hoses to the valves fast enough to kick the leg up to prevent damage.This is why the trim cylinders have a bypass system built into them(the balls and springs) that will let a subantial amount of oil bypass very quickly if pressure is exceded.If your pump has external cartridges just swap them as sugested above.

Check item 4 out on the link.If memory serves me correct the filter ataches to the hold cartridge.The plugs on the valve bodyare checks. bhttp://www.mercruiserparts.com/Show_Pictures3.asp?dnbr=880951%2000&ivar=images/CRUISER/880951.00/14.png&inbr=5398&bnbr=280&bdesc=PUMP%2FMOTOR+ASSEM BLY+%28Bottom+Mounted+Reservoir%29ody are just check balls.

It sounds like one of the Poppet valves is sticking or has dirt on the seat. The rebuild kit would include these. As preventive measure clean out the reservoirs each season to remove contaminates.
Dan

The poppet valves are located behind the Hexagon caps on part number one in the link below.
Dan

http://www.mercruiserparts.com/Show_...m+Mounted+Rese

Will follow all ideas when I get it home from hibernation. Tnks again for all help. Just looking at that excellent shot of your boat Candyman. COPS site - 03 Hammond run. Hope you have that in the dining room! Dave Brown

Thanks, I waited 6 seasons to get that shot. I even had Reggie autograph one for me. Are you guys planing on running any of the COPS runs this year? They are a great time. Nothing better than 50+ powerboats in a group running past a group of sailboats.
Dan

Yaa.. just registered with COPS. Sounds like a good group. Looking forward to more G0-Faster friends. Can't wait till spring. I see you can't either, on the comp after midnight!!