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View Full Version : HELP 16 will not trim underway!



DFLOWER
05-10-2000, 09:12 PM
Thanks guys,

Forrest & PaulO the switch works properly thumb up and drive goes up but not under way once the boat gets up to speed. Thumb down and drive goes down at any speed.

I have not used the boat since mid October so I Can't remember the exact speed when the trim fails. I have a stainless prop and I touched bottom alot last summer when we visited many different lakes. So with that type of prop the drive can really take a shot, although all the dings were at idle speed. Perhaps that tube releasing pressure theory could be it.

I printed out this page and will show it to the mechanic at our marina if he is open minded and does'nt mind.

Thanks Dave

[This message has been edited by DFLOWER (edited 05-11-2000).]

PaulO
05-11-2000, 12:30 AM
If the hydraulic lines to the trim pump have been disconnected, they may have been swapped in advertantly. I know because I did this myself. It seems that there is minimal force in one direction and maximum in the other. The clue would be that the trim switch is operating backwards (up for down...) unless of course someone rewired the switch or the pump to get it to work in the right direction. The only other causes I know of would be mega air in the system, insufficient oil level, or a bad pump. I hope it is my first guess. It is the easiest to rememdy.
PaulO

GeneD
05-11-2000, 08:10 AM
Ah ha!
I just went through this not too long ago, to the dismay of my pasengers.
Funny isn't it? You knwo you have a trim problem and you try to correct, but when you nail the throttle the bow sucks itself into the water. Causing all kinds of hairy handling.
The solution is simple, swap out the two hoses going into the pump and you are cured.
The reasson is that there is an impact safety feature on the Aplha trim pumps. A special valve will open up when you strike an unwater object and allow the drive to come up, protecting the drive from damage. When underway with the hoses switched, the pump's emergency valve thinks the boat is striking somthing and it releases it's pressure, making the drive go in.
Oh, and once you switch the hoses, you will have to switch the wires (the green and blue, remember, green grass, blue sky) going to the pump solenoids too, or else your trim switch will work opposite.
Simple fix, trust me and PaulO.

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GeneD
007
Melbourne, Florida

[This message has been edited by GeneD (edited 05-11-2000).]

Forrest
05-11-2000, 09:43 AM
Yea but like PaulO asks, does Dave need to press the down button to raise the drive??? If he presses the up botton and the drive goes up, then the hoses are not reversed, unless of course the up and down wires are reversed as well, but that would seem remote. I would bet that there is problem with a valve in the pump unit.

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Forrest

[This message has been edited by Forrest (edited 05-11-2000).]

Hotboat
05-11-2000, 08:51 PM
What about the trim limiter switch. Looking at the boat from the rear, it is the round large button on the left side of the swivel on the transom assembly. It has wires that go thru the transom assembly and connect to the trim pump. It is set to limit the travel when using the trim button. It may be bad or the wires corroded. The one on the right side is for the trim guage on the dash. I have just purchased a kit to replace both of mine on my 18 Classic this Sat. Could be the problem if it will not trim but will tilt.

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Hotboat

RickR,GroveCity
05-11-2000, 09:28 PM
dflower
What drive do you have?
Do you have a voltage drop (on your gauge) when trying to trim up at speed?
If yes you may have a trim motor going south.
A rebuild kit used to be available for early model high pressure pumps.

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RickR mailto:riggerb@aol.comriggerb@aol.com</A>

DFLOWER
05-11-2000, 10:49 PM
Thank's everyone,

I have an Alpha Drive 1995, I can't remember if there was a drop in the gauge but I will check into that friday when we test it out. There is no evidence of the wires being corroded, anyone else switching hoses or any rewiring of anything. Sounds like a pump I guess I will find out for sure this weekend.

Thanks Dave