12’ Mini Jet build

[ABMax24]

I don't like the mechanical seal setup on the doo pump. ive seen them leak after a big rock hit and the bottom bends up messing with the driveshaft angle. the splined shaft is tiny too.

That's my one frustration with it as well. Even a little bit of sand in it at the right time can cause it to leak. Granted they are easy to fix with a flat block and sandpaper to sand the carbon and steel surface flat again.

I've looked at a few different options and haven't found one I like, there are sealed bearings the can be put over the shaft that attach into the factory boot, the problem is if the bearing piles up it completely destroys the boot and you are left with a geyser coming into the boat, where with the mechanical seal I have never had a leak bad enough the bilge pump couldn't keep up. That being said I might find a duck bill (or whatever they are called) to put in the drain plug hole to help drain out water just in case I get a big leak in it.

 

[neilsleder]

A big part of it is in how you drive it too, being light and over-powered I'm afforded the luxury of speeding up before hitting shallow spots and pulling back on the RPM's while crossing them. Impact energy increases by a factor of 4 with a doubling in velocity, if I can pull back the rpm's to 3000 from 6000 when sucking stuff into the pump the pebbles hit the impeller with 1/4 the energy, this makes a tremendous difference on impeller wear. Now heavier boats with less power may not have this luxury as they need to keep the power on to get across.

Yah I am pretty familiar with how to go over skinny water!

 

[06 Dragon]

Seadoo pumps are actually pretty tough assuming the intake grate has small enough openings, I've run the stock impeller for over 75hrs and it is still usable. I switched to an even lighter solas impeller with a steeper pitch to pull the RPM down a little for fuel economy. These pumps spin fast and as such nick the leading edge of the impeller easily, the key is to keep the junk out of the pump in the first place, not build a tougher impeller. I also run a plastic wear ring with the theory being I will wreck the $40 ring instead of the $400 impeller.[/QUOTE]

Did you make you own wear ring? I watched a video the other day of a guy making his own for a personal watercraft impellar out of uhmw pe.

 

[neilsleder]

Seadoo pumps are actually pretty tough assuming the intake grate has small enough openings, I've run the stock impeller for over 75hrs and it is still usable. I switched to an even lighter solas impeller with a steeper pitch to pull the RPM down a little for fuel economy. These pumps spin fast and as such nick the leading edge of the impeller easily, the key is to keep the junk out of the pump in the first place, not build a tougher impeller. I also run a plastic wear ring with the theory being I will wreck the $40 ring instead of the $400 impeller.

Did you make you own wear ring? I watched a video the other day of a guy making his own for a personal watercraft impellar out of uhmw pe.[/QUOTE]

Impros and a few companies make an uhmw wear rings for the smaller pumps.

 

[iceman5689]

 

[ABMax24]

The factory wear ring is plastic, I have just stuck with it. Stainless is an aftermarket mod for these pumps.

 

[iceman5689]

If I were to do it over again I would of boxed in the pump and intake, pushing it further out the transom giving more engine bay room. They are tight for space.

 

[ABMax24]

You've got more room than I do, the nose of mine is much longer. My engine divider sits about 3 inches in front of the oil fill tube and the back of the seats are about 4 inches in front of that.

How big of fuel tanks are you planning?

 

[iceman5689]

80/l with a welded collar to cascade from a future 30l tank of needed.

 

[06 Dragon]

Looks good! Hopefully you have it water ready soon. Some of the rivers are opening up.
Are you building your own fuel tanks? I am thinking about adding a second one to mine.

 

[iceman5689]

No had a fella in pemberton machine a weld on bung that mates to the stock fuel pump and filter. Was too easy not to go with that.

 

[gunner3006]

Looking good man.

 

[NoBrakes!]

A good friend has a jet stream with a 255 in it. Professional welder, did the entire kit with tig. Corbeau baja low back front seats. Nice rig, stacked dimes lol.

 

[neilsleder]

A good friend has a jet stream with a 255 in it. Professional welder, did the entire kit with tig. Corbeau baja low back front seats. Nice rig, stacked dimes lol.

That would take awhile!

 

[ABMax24]

What are you going to run for a heat exchanger?

 

[NoBrakes!]

That would take awhile!

good winter project, long hours with water cooled torch and wireless pedal. It’s special for sure. The tanks, exchanger etc...

 

[iceman5689]

What are you going to run for a heat exchanger?

Shell and tube

 

[iceman5689]

Front flush mount led and UHMW checked off

 

[iceman5689]

Dash and pump protector bars

 

[gunner3006]

Front flush mount led and UHMW checked off
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I like the flush mounted or inset lights. Looks professional. Nice work.