Pump scupper, is it worth the trouble?

[michael950]

Is it worth the trouble to install a scupper into the pump, vs the transom?

Any problems doing that, is it inefficient, etc?



Anyone with pics?

 

[jetskiking]

I dont see any mechanical advantage on the scupper other than trying to get a clean look and making runnig dual scuppers possible with rear exhaust. I have heard of one way valves blowwing out from big tail landings and it could be an advantage to dump oneways in the pump.

 

[Big Kahuna]

I did not install one in my old hull, but there is one in my newer hull.......... intersted to see how it works.

 

[LBE]

I think it would be better in the pump area. I have no experience with the pump dump, but I think there would be less stress on the flaper, and less chance of blowing it out.

 

[cambo au]

i would say if you are going to cut your tray out to re foam then go the pump dump but if not go the rear i did bend the peice off aluminium on the flap of my home made rear scupper from big tail landings but since then i hhave installed a x metal scupper no probs as yet

 

[yamanube]

I put a one way in that dumps into my pump cavity, it was a little more work but if you have the foam out and hole for your holes its not a ton of work. I think it deffinitly looks nicer. And seems to work awesome so far, doesnt leak and dumps fast.

 

[yamanube]

Here is a pic before sanding and painting....

 

[Frosty]

i put both a transom and pump dump one way valve(s) in my SN... they work great together. I would say, if you have to refoam anyway, what the hell do it up and put one in.

 

[SJBrit]

One advantage of a pump dump is that you lose less foam. When you've installed a scupper or two, footholds and maybe a front exhaust, you've removed a LOT of flotation, and your ski won't float any more (they only just float when stock). Every bit of foam helps....

 

[yamanube]

Is it really less foam? How can that be?

(edit) I guess maybe if you put the drain way up towards the front of your pump cavity....

 

[SJBrit]

I guess maybe if you put the drain way up towards the front of your pump cavity....

I thought that was the way it's done?

 

[damnthathurt2]

seen this on d-rocs pics..
looks to be a good pic of how its done

 

[yamanube]

seen this on d-rocs pics..
looks to be a good pic of how its done

That gives you a good idea of whats going on but you dont have to do nearly that much surgery to get it in. I put mine in though a foothold cutout and its been working great, also the ski still has enough foam to float tail up when full of water.

 

[brentR]

i put both a transom and pump dump one way valve(s) in my SN... they work great together. I would say, if you have to refoam anyway, what the hell do it up and put one in.

too bad they both leak mister!!!!!!!! uke:

 

[Kaveman]

I put two pump dumps on a couple of my old skis. I did it similar to D-rocs but came through the firewall below the midshaft with a 45 degree fitting then over to the edge of the hull and another 45 that directed it straight toward the rear. Ran this into one way sump pump valves purchased at Grainger and then another 45 to redirect it into the pump cavity. They both performed great with only a slight leakage when left in the water motionless.

The steering cable tube was cut and removed and replaced with a piece of rubber hose.

By going under the midshaft you can put the drains on the bottom of the ski instead of 1-1 1/2" higher at the outer edge of the engine compartment.

I went pump cavity for the look, but I can see where it would be better for those hard tail first landings.