to scupper or not to scupper

[WaveDemon]

I've got all the stuff to scupper my ski but I'm worried about sinking it after a bail. I'm worried about the scupper quickly releasing all the trapped air in the ski when it's upside down and filling with water. To add a scupper means to remove some foam, I don't have a handle pole filled with foam so there goes a little more buoyancy.

What do you think?

 

[sjetrider]

All concerns of mine, as well as the concern of taking on water if and when boat is left on beach for an hr. at a time.

 

[WaveDemon]

a leaking scupper isn't a big concern for me. I've got dual bilge pumps that should take care of a small leak.

 

[WaveDemon]

okay, let's be clear.. are we talking

A) PRIMARILY surf ski
B) PRIMARILY flatwater ski

?

it's built for surf but will be about 60/40 surf vs flat.

 

[SuperJETT]

Fill your pole with foam and the area under the nose too for extra buoyancy.

If you're mainly in surf, a good hood and 2 bilge pumps plus the stock siphon works well.

 

[beachedflunkey]

Bail? You call that riding? :firedevil:
Actually I've come up a couple times to find my ski upside down. If it's running upside down for more than a couple seconds I'm usually getting towed in. I'm not sure if that's due to my one-way releasing the air, my carbs pulling water through my hood intakes, or both...

 

[WaveDemon]

Fill your pole with foam and the area under the nose too for extra buoyancy.

If you're mainly in surf, a good hood and 2 bilge pumps plus the stock siphon works well.

no pole on my SJ.

 

[Idok]

put the scupper in you wussy......we tried to get bill to install one

 

[superrob750]

do it.

 

[SuperJETT]

no pole on my SJ.

Oh, well, INSTALL ONE!!! :cheer::cheer::cheer:

:laugh2::laugh2::laugh2:

 

[SuperJETT]

I had a bail on Sunday off a decent wake doing an invert, I ended up probably 5-6 feet under, with my right foot in the foothold being the only attachment to the ski, and it was UNDER me. Ski came right up still running.

Scuppers don't let all the air out.

 

[Ollie Rastabean]

I think the big question with the scupper function is wether or not the motor is running when the boat is turtle. I have my idle high enough so that it is running when I get to it (even upside down). I also think a running motor has has less chance of water in the pipe making it to the plugs.

I agree with you if the motor is not running. The scupper will let air out of the engine compartment. BUT, the water has to make its way throught the baffles of the hood or through the handle pole. So, you have some time to get to it and flip it.

Now, think of the motor like a big air pump. At idle speed the motor is running approx 1300 rpm. The motor is 701ccs. Assuming 75% efficiency of the motor (2 stroke). You are pumping 180 gallons per minute (of air)out of the engine compartment. You are also replacing that with water. This means two things.

1. The engine compartment will be at a significant negative pressure and hence will hold the scupper closed.

2. With a low-profile hood you only have about 15 seconds to get to the boat before it pumps water to the carbs anyway (if upside down).

So, if you keep your idle high the suction from the motor will hold the scupper closed.

If your motor dies when you let the throttle go you still have a little bit of time to get to the boat when you are turtle anyway.

This is what a four hour deive back from Sebby will do for ya.

 

[Mouthfulloflake]

the 2 guys that I have ridden with that have scuppers, do not like them.

I dont think it will be anywhere NEAR the top of my list of things to do.

 

[WaveDemon]

I think the big question with the scupper function is wether or not the motor is running when the boat is turtle. I have my idle high enough so that it is running when I get to it (even upside down). I also think a running motor has has less chance of water in the pipe making it to the plugs.

I agree with you if the motor is not running. The scupper will let air out of the engine compartment. BUT, the water has to make its way throught the baffles of the hood or through the handle pole. So, you have some time to get to it and flip it.

Now, think of the motor like a big air pump. At idle speed the motor is running approx 1300 rpm. The motor is 701ccs. Assuming 75% efficiency of the motor (2 stroke). You are pumping 180 gallons per minute (of air)out of the engine compartment. You are also replacing that with water. This means two things.

1. The engine compartment will be at a significant negative pressure and hence will hold the scupper closed.

2. With a low-profile hood you only have about 15 seconds to get to the boat before it pumps water to the carbs anyway (if upside down).

So, if you keep your idle high the suction from the motor will hold the scupper closed.

If your motor dies when you let the throttle go you still have a little bit of time to get to the boat when you are turtle anyway.

This is what a four hour deive back from Sebby will do for ya.

what about when you break a hood latch and the hood is open a little, like what happend to me last ride but the ski is upside down. I guess I should probably tighten my straps before each ride.

 

[daylite67]

I never thought about a scupper letting all the air out of the hull...
I did the ol' home depot check valve and threw a 24/7 scupper on the outside and it still leaks a little. I have yet to find a 100% solution other than having a bilge pump also. When I had the Blaster that I painted pulled apart I noticed a lot of open space under the top piece that mounts to the engine cover. What about filling that in with foam and glassing over it, leaving room for the breather tube and cables/wires. It seems like that would reinforce it and make it more buoyant.

 

[Ollie Rastabean]

what about when you break a hood latch and the hood is open a little, like what happend to me last ride but the ski is upside down. I guess I should probably tighten my straps before each ride.

If your hood aint seated you can fill up with water just flipping it over.

-O

 

[daylite67]

the 2 guys that I have ridden with that have scuppers, do not like them.

I dont think it will be anywhere NEAR the top of my list of things to do.

My buddy that I ride with has decided that he is going to fill his in when we rebuild his ski this winter.
I like how fast they dump water, but it does come with a price.

 

[LBE]

I broke the pole out of the front of Mike Serlins round nose. Pole bracket had the fiberglass still attached which left a large hole in the ski, and it had the hood hooks attached so the hood could not be closed. The ski was basically sunk, but as soon as we started towing it the water drained out because of the scupper. Without it, pumps could not have kept up with the water intake. Not a really common situation but it saved the day.

I love the scupper and really can't imagine ridding without it now. I went the Home Depot route. I mounted it on the firewall side so it wouldn't blow out on tail landings, and it doen't leak! (Knock on wood) My bilge pump rarely comes on. I would suggest mounting it low in the hull. Most are mounted straight through which puts it up high. Mine is almost under the short shaft, the lowest point. You may have to use a piece of flexable hose to get it there but it is a better location, IMO.