intake tunnel question

[Cyberbmxer]

I have a 1991 waverunner III that I am using as a donor for a jet Jon build. would it be better for me or even possible to use a larger Jet tunnel from a different ski or am I going to get the same performance? at this point the setup has major corrosion and I would likely need to replace most of the unit.
thanks
Don

[hemmjo]

Re: intake tunnel question

When you say tunnel, I assumed you mean the fiberglass part of the hull that guides water into the pump?

Then when you say the set-up as "major corrosion", I am wondering if you are talking about the pump?

Generally speaking, the engine, pump, tunnel combination is a well engineered combination. The goal is to match the pump to the power of the engine and the tunnel to the water flow requirements of the pump.

As long as the new tunnel you use does not restrict the flow of water to the pump, you should be ok. It is important to keep in mind that the flow of water into the pump should remain smooth and straight with as little turbulence as possible to minimize cavitation inside the pump.

[Cyberbmxer]

Re: intake tunnel question

your explanation makes perfect sense and I think you answered my question. pretty much the entire pump and nozzle bacl to reverse gate is heavily corroded. even the ride plate. I mjust wondering if I replaced it all with a larger one would that be beneficial or not. what I did mean was this part

[john zigler]

Re: intake tunnel question

No, a larger pump tunnel will be of no benefit, or even fit your pump.... (Larger ones are 155mm, your pump is 144mm)