Lifeguard

I am a lifeguard chief for a company that operates inland lake beaches. We currently operate with older Waverunner XL700s that are getting long in the tooth. I am trying to do a cost analysis for budgeting of what the savings will be by upgrading to newer Waverunner VX models. I can find plenty of information on the VX gallons per hour at various speeds, although I think the 30mph or 35mph estimates would be more useful at predicting our actual operating range. But I can't find any measures online of what the gph for the XL700 are. Does anyone have the number on what the XL700 has been measured at in the past, either from the manufacturer, a magazine evaluation, or some method of rough calculation to compare to estimate fuel and oil savings? Thanks.

Ernest T

I've never seen published numbers for the XL700. However I have seen numbers for the VX700 which is basically a VX hull with the 700 2 stroke engine in it. Yamaha only sells them overseas. In that comparison the VX700 burns about 1.5 - 2.0 gph more fuel than the VX with the MR1 4 stroke at WOT. At cruising speeds (25-30 mph) the 4 stroke would burn around 0.5 gph less than the 2 stroke.

Now you also have to consider that the XL700 was about 75 lbs. lighter than the VX700. That would make the numbers closer, but I'm pretty sure the 4 stroke VX will save you fuel over time.

Don't know if this helps or confuses.

Good luck on the new skis.

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2008 Yamaha FX HO Cruiser
2010 Hurricane Sundeck 2100

Lifeguard

Thanks. I couldn't find info on the VX700 either, but forgot to mention it. The VX700 is heavier like you said, so it should use more gph. But it is a different hull profile, so I don't know how that change in hull affects it. The fact that Yamaha retired its XL hull suggests that maybe the VX hull is more efficient in the water, which might mean that the increase in weight might be negated in efficiency in the hull design, and then the XL700 and VX700 would similar in gph. I already know how much oil and gas our XL700s consume over the summer season, but I need a fairly accurate projection of what the fuel savings would be to figure out how much of our PWC fuel and maintenance budget we will have available to purchasing new craft. If I assume the VX1100 burns 3gph at 30mph which I've seen measured, and the VX700 is comparable to the XL700 burning 0.5gph more at that speed, then I should expect a 14% reduction in fuel costs on top of the 100% savings on 2 stroke oil, minus the cost of 3qt of 4 stroke oil with filter and 2 extra spark plugs at the end of the season. I was hoping for a more dramatic savings than that to help pay the steep cost of buying new craft over the next few seasons.

Ernest T

Yea, the problem is that the XL700 was probably Yamaha's most efficient 2 stroke ski. If you were to compare numbers to just about any of their other 2 strokes, you would see an amazing difference.

Maybe you can sell them on the longevity of the 4 stroke engine. With proper maintanence that 4 stroke will easily give you 5 times the hours of the 2 stroke.

__________________
2008 Yamaha FX HO Cruiser
2010 Hurricane Sundeck 2100

Lifeguard

Yeah, I was starting to draw that same conclusion when I saw the half gph difference. As far as longevity, our oldest ski is a 2001 and aside from cleaning the carbs and fuel lines a few seasons back, it has seen no repairs. I've only recently put hour meters on, so I don't know how many hours they have. But if the 1100 lasts 5x longer, new craft should last us for the next century. Actually our real problem is hull maintenance, we are starting to see stress around the jet drive housing where we are seeing leaks and cracks in this area that some liberal silicone is plugging up, but the sheet molded compound is going to need to be cut out and replaced eventually. I saw some VX hulls sans engines on Craigslist last fall, maybe I should have picked them up and swapped in the 700 engines instead?