Recent content by kevbo

I guess the question is "Can you ride all day bent way over?" If so get whatever you want. If not you will get a really sore back trying to.

Flat water flip skis are very short and have very short poles. Going over 15 MPH requires the rider be bent way over and thats not very comfortable. You can stand straight up on full length Superjet but it wont flip without a big wave. Free ride skis are somewhere in between. If you want to...

Positive pressure at the inlet is very important since water boils in a vacuum. The inlet pressure is limited by the weight and footprint of a planed hull. Any more pressure than that means water will be pushed back into the slipstream causing drag. Water won’t compress, it just gets...

Oh wow, another flip hull.

It may be because most riders like to lower the popoff pressure plus aftermarket manifolds have no crossover port. This makes everything, especially the pilot circuit much richer all by itself. I recommend you forget about most of what you have read and just tune the carbs. Pick a popoff...

Standups run on the surface so they never get clean water like a sitdown does. Standups need long shallow inlet ramps where sitdown inlets end up shorter after being optimized for their intended top speed. I built a load cell years ago and was able to get nearly 700 lbs of static thrust from...

Look up the dynamic pressure of water then figure the area of your nozzle. Measure your static thrust and you will find that any decent running ski will be over 70 PSI. Let me add that I have found it a lot easier to increase low speed thrust with a larger nozzle than it is by adding power. Our...

Your bottom adjusters are for idle only and you have them too lean. If it responds well from 1/4 throttle then the pilots are okay. Make sure the top screws are opened so that the RPM ends up a little below max or just wherever the ski accelerates the hardest. The impeller could be causing...

I once tried to sell jetski parts, Ill never do that again. It's short bus city out there.

X2s are effectively long hulls and have limited space in the engine bay. Moving the handlebars aft 6" gives the hull much better fore/aft balance for average sized riders. Making things fit in the engine bay requires some engineering and careful fabrication in order to keep it clean and...

You could be that guy if you stay in the game for 30 years. Almost every jetski enthusiast today will be out of the sport fairly quickly.

I have shimmed some Watercross of Texas grates as deep as I could get them. I never found the extra drag to be remarkable.

I have done testing with smaller engines many years ago. It was interesting to see what port timings worked best with mufflers, open exhausts, and tuned pipes. We have a lot of open exhaust data from the development of outboard engines. There is also a lot of info for strictly tuned pipe...

Having a "good" dyno chart may save some time with pump load adjustments. I think many guys just want to dyno race. I have watched car guys get overly excited when they made 5 more HP at redline rpm.

Engine induced braking? How can that happen with a jet drive?