School me about trim pumps
 

New boat to me; tabs move like Lance Armstrong on steroids, drives move "normal" speed, hydraulic hatch moves like a fat kid in gym class, it just takes forever.

Are there orfices that control fluid flow? How is speed controlled?


Far left is hatch:

http://33outlaw.zenfolio.com/img/s1/...26835918-4.jpg



http://33outlaw.zenfolio.com/img/s1/...26836050-4.jpg

It's cold out it will,go,faster when its warm Out. Mine almost didnt open last,weekend.

Mark

Dan, you can adjust the pressure on these pumps. However, you want to take notes on what changes you make to them.

For example, on the hatch pump. You'll want to remove the reservoir can, either a screw or bolt on bottom of it. Once you remove that, you will see the jam nuts for the relief valves. Without having a psi gauge, youll have to trial and error it.

Loosen the jam nut, and turn the valve screw in 1/2 turn on each (both up and down side). Replace reservoir, and try it. It may take a couple times to get it where you want it. Like MrCig said though, when its cold out, it will move slower.

For those tab pumps, it seems like you need to reduce the pressure. Those things do move friggin fast, and can prob get you in trouble. Same procedure as above, but youll want to back the screws out, instead of turning them in. Keep track of what changes you make, so if all else you can put it back to its current setting.

They are all moving different 'weight'. Hatch, very heavy, ram is probably closer to the rear therefore working harder to push the hatch up, requires a lot of force.

Tabs are very light, don't require a lot of force to move.

Could be that the hatch pump is getting tired, from years of having to lift a heavy hatch up too. You could swap the pump with one of your tab pumps and see if it helps any.

its a matter of volume tabs smallest, then drives and hatch ram will take most fluid to move. hatch normally come down quicker due to ram displacing fluid. increase of pressure will increase output volume.

This was all pretty much a re-rig. My guess is the hatch pump is turned down a bit.

I used to have a hydraulic hatch on my old 40 Excalibur, that friggin thing would toss someone in the water in about 2 seconds when you touched the ''up'' button. My buddies Cig Bullet also had a hyd hatch, also moved very fast.

With drives, you need lots of ''UP'' psi, to overcome the force of the propeller thrust while underway. WAAAAYYY more than you'd need to raise a 150lb hatch. I once had a trim pump going south. To get it to trim out underway, id have to back off the throttle on that engine, hit the up button, and then get back on the throttle. Raised the drive fine standing still though!

Thanx Joe Fountain, thats the info I was looking for!

btw, ran new A/C intake and discharge lines, electric, mounted A/C. Just in time for winter :daz:

I was under the impression that these are positive-displacement pumps, in which case the only thing that will speed things up is a larger size pump rotor set or a faster motor. It's all about pump displacement rate versus ram cavity volume.

I could be wrong... ;)

My one drive moves faster that the other, it sucks. I've been dealing with it, but it needs to be fixed at some point, sounds like a pain in the neck. have to remove and reinstall the pump and all trial and error with notes. There should be a better way.

there is. buy 2 brand new pumps...

Trim pumps are parker 108 series hyd. power units.

Parker makes these in four different volumes
.0098,.0187,.0246.0321 per revolution.

I know that trim pumps are higher volume than K-Planes but i am not at home so i cant look up the pump sizes.

I would bet that you have trim pumps hooked to your K-Planes.

Correct!

I have a trim tab pump for my drive and it's wicked slow (but strong enough), so I'll be replacing the rotor section of the during the winter.

Aren't those the O/B style pumps. Shouldn't the trim pump be a larger Oildyne I/O style with tank?

I tried adjusting the hatch pump, played with it for a about an hour but there was no difference in speed..... now it makes a funny sound ha!

They are both Brand NEW sa

Ok so that makes sense... I would need K planes pumps.
As far as the hatch I hooked up a different pump and no difference so I`m going to assume its the cylinder thats at fault. not that its broke just thats its slow.

How do you know what volume your pump is putting out?? I have one drive reacting faster than the other.

That seems to be a common issue.. I played musical chairs with my pumps, switched lines etc and one of my drives is still slower going down no matter what pump is running it.... I think its in the cylinders personally.

Is there any way of identifying the pump volume by markings on the pumps? I need a pump for k planes. I have 1 need a match.