vx 1000 vs lx ultra, long range offshore fishing and spearfishing?

[TimeBandit]

Where I live there are a lot of genuine full OEM 2011 1100cc waveriders. Thats a shame as the gas is MUCH better on the 1100cc model, the 1800cc only gets 2/3 the fuel economy.

Well, I have great news for you ... because your (2/3rd) notion is not even close to being accurate. Aside from real-world testimonials from actual owners of both crafts - link here - the math is not that simple. I can guess, one arrives at 2/3 via 1100cc / 1800cc into the calculator, resulting in a 0.6, aka 2/3rds. That might be a good enough formula if both engines turned the same RPM bands - but they don't. Therefore, you need to bring time into the equation.

Not talking down to anyone's intelligence here... so please consider for layman's sake, the cylinders are all little "lungs". If you think of the CCs as total lung-capacity and RPMs as breaths per minute, you see the the 1.8 breathes deeper than the MR1, yet takes considerably less breaths. So if we can comparatively calculate how much air these engines actually breathe, we can make some assumptions on how much gas would be ratio'ed in.

Let's take max RPM x total cc for both platforms to see the total volume of air being processed through each engine over time :

7,800 x 1,800 = 1,4040,000 cc (1.8L NA)
11,200 x 1,100 = 1,2320,000 cc (MR1 HO)

Now let's factor the difference of 1,2320,000 / 1,4040,000 = 0.877492877 aka roughly just 9% less fuel economy for the 1.8L ... (nowhere near 30%).

While "my" math is far from accurately taking into account many other real factors... it does agree with the spit-ball average 10% that many folk (past owners) have observed personally out on the water.

It seems the 1800cc yammy engine is popular.

Why not the naturally aspirated ST3 hull Seadoo?

As far a the ST3 platform, my only reservation on Sea Doo's are the carbon seal architecture. I know this a controversial subject to many, but really the only controversial part, is the propensity of such a failure. So, while I won't argue the chances of such a failure, I will contend that such a failure would permit a very fast rate of water into the hull, making sinking/swamp-age a real threat.
That said, I think there is a way to retro-fit the older needle-bearing seal setup in-place of the carbon ring system, and while those can fail/rust as well, I understand needle bearing failures are progress enough to know when something is wrong (aka don't often "surprise") resulting in an instant-gaping hole.

[SpearoSki]

Well, I have great news for you ... because your (2/3rd) notion is not even close to being accurate

Dude that was long and really unrequired lmao. I was quoting a side by side comparison I read in an article, not coming up with my own "notions". Its not a huge deal either way anyway.

I agree, perhaps the Yamaha is a safer bet. I looked at the newer VX deluxe and its service schedule, there is sooo much room and really all you have to do is check and replace items, nothing scary about servicing a Yamaha.

[boudin]

Just saw this pop up and figured I'd weigh-in on VX fuel economy. In our Yamaha SUV MR1 conversions, with the 1052cc MR1 (VX motor), an 18.5 gal FX fuel tank, we see a little over 100 miles at approx. 6000 rpm before the fuel light blips on. Pretty much the same for the 998cc MR1 (FX140 motor). We do 200 mile round trips on the river carrying an extra 20 gallons of fuel per ski.

-Greg