Why The Sport Jet?

Mercury Marine OptiMax Inboard Sport Jet verses the Outboard Jet

I’m often asked,
 “Kevin, why don’t you build outboard jet boats?" For me the answer is simple. Pound for pound, dollar for dollar, there’s not an outboard jet on the planet that can match the overall performance of Mercury's 200 HP OptiMax SportJet.

It all starts with water flow…
If we look at the illustration below, it’s easy to see how the Sport Jet pump flows more water, with less effort, than the OB Jet pump. This translates into more usable engine horsepower, thus better fuel economy.

Power loss…
It’s widely accepted that engines fitted with OB Jet pumps lose 30% - 35% of available horsepower.  The Sport Jet pump is a bit harder to pin down, but…many have the loss in the 10% - 12% range. For ease of comparison, I'll use the lower percentage loss of each.

200HP Eng / OB Jet - 30%  @140 HP  
200HP Eng / Sport Jet - 10% @180 HP

Loading the pump…
Let's look at how the two pump designs get water to the impeller or “loading” the pump as many call it.  To load the OB Jet, the intake protrudes into the water flow. This protrusion occurs on all OB Jets regardless of hull design. Aside from the obvious impact dangers, this design puts a substantial performance robbing drag on the craft. Let off the throttle and the OB Jet intake digs water like a backhoe bucket.  With a properly designed hull, the Sport Jet intake is mounted flush with the hull bottom. Flush design equates to little or no drag on the hull. Let off the throttle of the Sport Jet and she glides gently to a stop.

No more hand over hand to turn the boat. With the Sport Jet, you’re not turning the motor… just the steering nozzle. Starting at the twelve o’clock position all one must do is rotate the wheel a quarter turn in either direction, the boat responds that quickly.

Low center of gravity…
The Sport Jet design moves the engine from high and outside the craft to low and inside the craft. No need to worry about your multi thousand dollar investment getting whacked by your buddies ½ oz spinner bait, road debris, or low lying tree branches.  With the power unit inside, the hull planes faster, cavitates less, responds quicker, and is easier to control off plane with your bow mount trolling motor.

Power trim & power jack plates…
Some OB Jet boats need both to perform well. Talk about multi tasking! Let me see......Pick my line through this boulder infested channel, grip the steering wheel tightly with one hand (‘cause I hafta turn the entire engine to steer), trim the motor to the correct attitude, adjust the engine height so as not to cavitate in rapids and find the perfect throttle position to compensate for hull slide. I’m not saying it can’t be done, I’ve been with guys who are masters at it!

Now me, I like things simple. Few Sport Jet powered crafts need power trim. None need jack plates. Steering wheel & throttle will get the job done.

Fuel Usage...

Betcha didn't know this.  In two similar size crafts @ 30mph, the 200 Opti Sport Jet uses less fuel than Yamaha's 115/80 & 90/65 four stroke OB jets. 

Clogs Happen... This will take a while so get comfy...

I'm biased.  I see the Sport Jet thru rose colored glasses. For me, intake clogs are of little concern. With a bit of common sense, experience, and good operating skills, it should be of little concern to you.

That said, OB Jets may have the advantage when it comes to clearing intake clogs. Good thing they do, because they clog easier than the Sport Jet. Many intake clogs that shut down an OB Jet are barely noticeable with the Sport Jet.

Above, you'll notice the word "may". I said may, because 99% of Sport Jet Intake clogs, can be cleared with a simple downward stroke of the optional EZ Clean grate or a weed rake.

The other 1%? Well, that can be a bummer. Although there are several "tips" I can offer, there will be times you'll have to get in the water and clear the intake. Not a big deal in the summer. But if the water is cold, it could be a long idle back to the launch.

As of this writing, I have had to get wet only two times in the last five years. Both times 'I didn't have my "weed rake".