WEE Boats - Engines Jet Unit Tech info

[Karl]

Its getting water too the filter thats the problem with these units cookie.

Yep that is true. It is only a problem on rivers with fine gravel.

In theory the over temp alarm light should come on and the CDI rev limit to alert you to a problem. This setup worked well on the 750, but doesn't seem to work on the 1100's. Probably because there is no water flow for the temperature sensor to act on.

[Brizz]

Just looked at the STX pump and it has pretty much what steely has created except the hose outlet is bolt on.  I also intend to play around with some type of pressure switch between the pump and filter to warn of loss of water pressure. Will look for some type of switch off the shelf but may play around with a dishwasher water pressure sensor of which I have heaps.   

[Karl]

Yep that is true. It is only a problem on rivers with fine gravel.

In theory the over temp alarm light should come on and the CDI rev limit to alert you to a problem. This setup worked well on the 750, but doesn't seem to work on the 1100's. Probably because there is no water flow for the temperature sensor to act on.

I have to correct this post as I found the fault with my setup when I ripped out all the redundant/extra wiring from the KATS system. One of the temp sensor wires going from the temp switch to the CDI and gauge unit was broken internally.  Replaced the wire so will be interesting to see how it goes.

[Paul]

I have to correct this post as I found the fault with my setup

Is the new (small holes) cooling takeoff sorted too?

[AlexC]

Another question that I often wonder is the intake grill size. I feel like it should be a ratio of the pump area, but the prop pitch might as well? Is there a rule of thumb for this? I've heard that if it's to big it can "burp" at high speeds, but to small and the velocities get to high and it aerates/cavitates.

[jetdesign]

There is possibly a whole thesis that could be written (and probably has) to do with intake size,shape and the hydro dynamic efficiency of differing designs
the only proper way to approach this question is to test,test,test
 

[AlexC]

no generic rule for a ruff and dirty size on these small jetski boats eh? How are you sizing your intakes?

[jetdesign]

no generic rule for a ruff and dirty size on these small jetski boats eh? How are you sizing your intakes?

My way is to work out the cross sectional area of the original intake foot print
then add the cross sectional area of the edge of the grill bars and viola there you have it

[souldoubt]

Any thoughts on a Polaris 785 Pro for engine and pump.  140 hp 148 mm pump.

[mohawk]

polaris pumps are good, possibly the best design as far as jetski units are concerned and the motors go like hell 

[Matthewf/Norbert/TuiDog]

blades for kawasaki pump      left to right in photos      *kawasaki factory           *Solas           *Skat

[heemi.v8]

 I like the shiny one

[Karl]

Kawasaki 1100 STX unit after 2 days gravel pumping on the Ngaruroro.

OD's are still OK but leading edge is a bit hooked.

[Matthewf/Norbert/TuiDog]

How does  stator look

[Karl]

It's fine.

I also have a Polaris unit (with a stainless stator) that I will modify to fit the Kawasaki intake, but stator wear doesn't seem to be an issue so I might hold off and use it for the next project.