A little insight on "newer" DOOs.

[AKnarrowback]

Hi Guys,

I'm trying another experiment on my old DOOs, in this case it's my 94 XP.

What I'm curious about is where the air intakes are located on the "newer" technology. Newer being 95 on up since my background is mostly on the 88-94 technology when I worked on them as a mechanic (yes I have ridden an original 88 with the hinged seat and one piece head, it ran equal to a twin carb xp 580).

I'm having fun tweaking the trim nozzle angle and am throwing the XP around a bunch and it takes on water too fast.

The air intakes are through the vents by the knees, through the seat and into the driveline area. The other intakes are the two smaller holes on either side of the hood hinge in the nose. Both seem like a "scoop" to shove water in rather than a well placed intake to avoid excess water intake.

I realize the newer tech isn't going to dive under as much as mine but I'm sure they have improved on the intake location somehow? Where is the intake on the Sparks?

What I'm testing right now is blocking off the seat intakes and the nose intakes. Since my gas gauge has been dead since I aquired the machine I removed it, drilled a series of 1 inch holes in the removeable cover on the bottom of the hood and an equal number of holes in the upper rear panel of the cargo bin above the orange storage tubes. Air goes in the hood, through the front cargo box and into the hull.

I adjusted the seat front mount and rear post down 1/4 inch to seal the seat tighter. I ran a 1/2 inch thick weather strip on the underside of the cargo bin to create more tension on the front cover to make a tighter seal.

Hopefully drawing all my combustion air in from the dashboard area will minimize the water intake when I'm throwing the machine around since the gauges are rarely fully submerged.

Anyone else tried a work around on the water intake into the hull on this generation of machine?

 

[mikidymac]

Newer ones are about the same.
If you are subing it then add an electric bilge pump.

 

[AKnarrowback]

Seat of the pants review on the results here.

I just went out and did 5 minutes of throwing the machine around, not total submarine but getting all but the guages and bars under. The same riding I would normally do that would fill the hull to the bottom of the air box in a few minutes except this time there was, maybe, half a gallon in the hull. Very good success with the experiment.

The trade off is you have to do a bit of a "hack job" to the machine. My rules for this experiment were to only cut pieces that are redily available on ebay and no cutting to the hull itself.

I cut another hole between the tach and the stock hole where the gas guage used to be. I added a few more holes to the access panel on the hood and a few more in the cargo box. Tightening the areas where the seat and hood seals made an improvement and blocking off the seat and hull intakes by the hood in the nose obviously stopped water intake into the hull.

Performance wise the wide open throttle running was not changed. I actually hit a personal best for my 94 of 53.6 mph on gps but I don't attribute that to the intake experiment but it does reinforce that the motor is not starving for air. I just hit some perfect water and got lucky.

I threw in pictures of the holes I cut. It looks ugly as sin so don't judge the craftsmenship on this one..... The intakes were just covered over with a quick shot of duct tape and I'll be cleaning those up later. I do have access to a expert with a CAD program and a 3D printer to build a cover plate for the gauge face to hide the two holes and still have free flowing air intake ability.

I know many of you take pride in a polished machine and I am very impressed in what I have seen on this site. My machines are always existing on a budget with function taking priority of looks. If I want to do something with a machine and something as simple as a poor intake design blocks me from having fun, well, I find a way around it while leaving the machine reliable and safe. This "mod" has room for improvement but I wanted to see if the old body machines can be reworked to keep from drawing in such large amounts of water while throwing them around. As for getting water in the cargo box area, that thing has never been dry at the end of a ride so, in my opinion, nothing has changed.

I also tweaked the trim cable adjustment a bit. I drilled another hole on the trim ring arm roughly half an inch further back from the stock hole. I had to spin the ball joint out a couple of turns and adjust the other end of the cable, at the motor, back in order to get the full range of the motor while also getting more "up angle" on the trim ring. The result is being able to stand the machine up all day, very simple after a spin, easy to do from a dead start. Still enough down angle to keep from bouncing when running fast in a straight line. Functional issues are that while running wide open, if you are trimmed down, you can't run the trim to the full up position before the current sensing kicks in and shuts off the trim motor. With all that thrust trying to push the nozzle straight you can only divert it a certain amount before the trim motor gets over loaded. The good side is the trim stops right about where the best speed is since having the nozzle trimmed full up knocks about three mph off the top speed, it does make a nice rooster tail though. You just have to remember to give the trim a kick down then bring it back up to get full trim up once you slow down to play. Next summer I'll get the hang of really balancing that thing on the tail, but to do that you have to get your butt in the water and since it's just above 40F in there...... Well, this is as far back as I am taking it this season.