03 GTX 4tec SC

[jetworx hawaii]

Ski seems to be running slow. The ski is used for tow in surfing at North Shore, Oahu HI. Few months ago tried a Skat Trak prop 14/19 blade. Ski turned about 6900 rpm didn't notice the mph. Just today I tried another Skat prop 15/19 3 blade. The ski hit about 6750rpm at about 48mph. Not the best of conditions for testing, thought. I came off the bottom pretty well but seems to top out. I new to the 4 stroke, but think this ski should do a lot better that what its doing. I guess my question is:

How do you tell if the SC is working correctly?
What should the rpm on a stock GTX be?


Aloha...

[01xdime]

Jetworx you should be running 7500rpms easily with a stock ski. Both of those props are too steep if your ski is bone stock. I'm planning on doing $5000 worth of mods to my 03 GTX SC and i should then be able to turn a 14/19. You should be able to hear your SC working if you have the seat off you should hear a high pitch whining noise. Did you have problems with the ski before you changed props?

[jetworx hawaii]

The ski belongs to a good friend that does tow in surfing. He was looking for a prop with a lot of bottom end and good hook up in the surf. The 14/19 I got about a 200 rpm more than the 15/19. Not sure what the ski was turning with the stock prop it was pretty chewed up. That's the reason it was changed.

When I was riding it today I could hear a whinning noise with the seat off. But the ski still seems slow..

[01xdime]

I'm not sure what pitch prop but for sure try a Riva racing intake grate and change your wear ring. You crazy ass surfer boys need to ride in the water not the sand!

[Shibby1485]

how many hours are on this machine? ... u said a skat prop.. is it a 3-blade or 4-blade prop? do you know anyone with the same ski, can u swap impellers with them for a couple hours? i might plant my bets on the supercahrger clutch, altho i think u have prop pitch issues as well.

[01xdime]

I'm not saying everything is the same but when the SC clutch went on my GTX i wasn't seeing any higher than 6500-6600 rpms.

[mjammer]

Sounds like the SC is going to me. The Skat prop for the '03 SC is a 16/21 which I have an turn 7500-7600 no problem. This is a 3 blade prop.

[jetworx hawaii]

All,

Running a Worx intake grate, the wear ring is new change it a couple weeks ago. It was pretty messed up. It has about 140 hrs on it. The props I tried was a Skat 14/19 4 blade, turned 6900 rpm. The 15/19 3 blade turned about 6750 only 48/49 mph on speedo.
How can you determine if the clutch in the SC is going out? And if so how do I fix it? I'm new to the 4 stroke. All help appreciated.

What would be a good prop for a stock boat, need good hook up in surf, and low end tork?

If only I could keep them in the surf and not in the sand..

Aloha

[Shibby1485]

i know some people say doing this doesn't mean diddly squat... but it's worked 100% of the time for me and my buddy so far.... take the inlet hose off the supercharger, stick your finger in there and try to spin the supercharger impeller with your finger... if it spins real freely and lose with little or no restriction, i'm planted on your clutch slipping.

this trick works alot better with the 04 and up skis bc if the ceramic blows apart, it's gone. the 03 skis dont blow apart, they jsut slip alot more...

to test the supercharger slipping, you need a torque wrench and a tool to insert into the head to lock up the cam

[RustySeaRustyDoo]

You probably are better of getting a HD one anyway....