Trim pump

[smokediver]

I am kinda stumped. My drive will stay trimmed all the way up but at anything less than all out the drive will slowly drop.

[Tidbart]

http://www.boatfix.com/merc/Servmanl/6/6A5R3.PDF

Section 5 of the Merc manual on the oildyne pumps. May come in handy. Nothing real specific as to your problem.

I doubt an electrical issue, so focus on the mechanical. Unfortunately, the test procedures require a special set of gauges for most testing.

FWIW..If I was to guess, pressure relief valve or seals in the pump.

B

[smokediver]

Thanks bob. I think a new pump might be the way to go !!

[Tidbart]

Here is one....

http://www.ebay.com/itm/231013154170?ssPageName=STRK:MEWAX:IT&_trksid=p3984.m1423.l2649

[Tidbart]

and one by me....

http://orlando.craigslist.org/boa/3933837988.html

[MOP]

Sounds like you have a small spec of junk at the valve, before you spend $$ a simple try is to borrow a pair of trim lines. Disconnect yours and install the other set, put the ends into a cut off clean jug. Put enough oil in the jug to insure they don't suck air, fill the resivour then cycle the pump up and down a few times. Many times running the pump a max free flow will pass the junk out of the valve, also it is very easy to remove the valve body to clean. 90% of the time I have found tiny bits of Teflon tape being the cause.

Phil

[smokediver]

Good idea Phil i will try that first. If not. Thanks Bob !!