Too Much WOT?

[tdonoughue]

For me WOT is a matter of comfort. Rarely am I on water where I can do WOT comfortably (e.g. not bounced out of the boat). So when I am on flat water, yes, I have some fun with some WOT with the kids.

As to @Gthunter5 question... I would think that most of the wear/tear on the engine would be seal degradation due to heat (ultimately dissipated in the cooling stream), which would be higher at higher RPM. So I don't know that it is a matter of 'work' that the engine is doing as much as engine speed. The thing about taking off is that you are spending a lot of RPM but not getting a lot of distance at the beginning, which is the worst efficiency you can get. When you are cruising, you are wearing the engine at maximum, but also going maximum distance for that wear.

IMHO, etc.

 

[Gthunter5]

Engine seal or prop shaft seal exiting the craft?

Is engine seal labrynth, lip or maybe magnetic?

 

[SCSTWG]

I rarely ever hit WOT! I'll do it on occassion here and there only when I find flat water, but very rare! Wife starts yelling at me north of 30mph and she's freaking out north of 40mph. White knuckles north of 50mph.

I'll cruise somewhere bewtween 25-30 - it's calmer, smoother, more relaxed - and I'm not really in any hurry anyways. Besides - I'll spill my beer at WOT!

This!

 

[davel501]

There was a thread like this on the other site and the point made there was that these 1.8s are built to run in the 12,000+ range but are limited down to 8000 rpm. We just get to feel like we are going WOT, but the engine has more to give. Yamaha factored in longevity.

 

[Seadeals]

I have the mr1s. A few buddies who are fanatics about Yamaha motorcycles (including engine rebuilds) stand behind the great design but still cautioned about common effects of prolonged high rpm use. Sure they can go something like 12-14k+ on a bike; but you are only there for a second or two before grabbing another gear or ending up a grease spot. The thought shared is piston (ring) velocity at high rpms is very fast (sure we could do the math) and that certainly leads to wear from friction/heat when sustained for long periods. It should be evident in the compression readings if that starts to take a toll. How often does everyone measure compression? I did when I bought, but how long (hours/years) before you should check again?

 

[octavio3311]

I can tell you first hand about the reliability of the MR1's. I campaigned an 04' R1 for 2 seasons. In those 2 seasons, I bounced her off her rev limiter every single lap, every single corner - she lived at 13,000 rpms. I did weekly oil changes, went thru lots of rear tires, a couple of clutch plates, repaired some crash damage (if u ain't crashing, then u ain't trying) - the motor purred like a kitten.

And the 1.8's have been proven by the jet ski rental industry.

The least of my worries would be the motors.

 

[jdonalds]

These are PWC engines. Most modern PWC 4-strokes will go for over 1,000 hours without problems (well don't count SeaDoo in that comment, or any supercharged or turbo ski). When I sold my Honda ski a few months back it had 400 hours on it with zero problems. At least 250 of those hours were on salt water. I don't know how many were WOT but a lot, perhaps 50 or more.

In the Sacramento River Delta, with the Honda ski, we would go through most of a 16 gallon tank of gas WOT between Stockton and Sacramento. Then we'd eat lunch, gas up, and WOT all the way back, a total distance of about 120 miles. On the Colorado River we did much the same on a 123 mile round trip one day with 3 on board. These were club trips with about 20 riders on all types of skis.

Honda and Yamaha don't over-stress their engines, and they don't allow you to either as long as you don't make mods to the engines. WOT is no problem for these modern engines because they are de-tuned. I put on about 100 hours on the Honda over the past three years on calm lake Shasta. Much of that was WOT.

Having been a member of a ski club for 9 years I can say I've never seen a Honda, Kawasaki, or Yamaha ski break down or interfere with a club ride and a great deal of that was at WOT. I don't even remember more than 2 or 3 skis ever having major engine problems in the Honda/Yamaha/Kawasaki group over the 9 years I've been in the club. We have over 100 skis in our club (SoCalWaterCraftClub.com). Check with the ski rental companies. They put 1,000 hours on 4-stroke skis all the time without rebuilds. A lot of the rebuild mentality comes from 2-strokes where they might only last 200 hours between builds. These engines have the distinct advantage of being water cooled from a constant source so they simply never overheat.

If you put 100,000 on a Honda Civic at an average of 50mph it will take you 2,000 hours. And most people know a Honda Civic is just getting broken in at 100,000 miles. You may not be pushing your Civic like a boat or ski but still the Civic has much more severe heating and cold to deal with along with air conditioners and power steering. etc. Many people think Civics are capable of 300,000 miles without an engine rebuild. That's the equivalent of 6,000 engine hours at 50mph.

SeaDoos are great for racing. The company has no qualms about pushing their engines to the max. Those skis have many after market options to increase the power. But many of my friends who race with SeaDoo skis pay a price in reliability, especially with aftermarket enhancements. We are fortunate to have Yamaha engines, perhaps the most reliable ski engines in the world. I personally believe Honda engines (non-turbo) are even better but I'm biased. Too bad Honda dropped out of the ski market and doesn't make jet boats.

Now as for running the SX210 at WOT it is pretty rare for us. It's too noisy, windy, and consumes way too much fuel at 40+mph. BoatTest says the SX210 is most fuel efficient at about 30mph so I have the PerfectPass cruise set at 30mph. I lock it in and let the PP be kind to my fuel budget.