Supercharged Jet Skis tend to be unreliable - why

[Sho'Nuff]

I know this is a car oriented forum but I thought a post about personal water craft (PWC) would be ok. Mods please move if this is the wrong spot.

Long story short I am in the market for a new or used jet ski. Since this is a fairly substantial purchase I have been researching the heck out of the various models, engines, etc. I've come to the conclusion that I would like one of the supercharged models (e.g., Sea Doo RXPX, Kawasaki 300X, etc.), but I am very concerned about the reports I've been reading re: the reliability of supercharged jet skis. Most of the reports I've read say that the supercharger needs to be rebuilt at 100 hours, else major mechanical failure is likely to ensue (i.e., blown engine). For me that would mean that I would be looking at a supercharger rebuild every other year, as I would likely ride the ski EDIT ~50 hours a season /EDIT. That's ~$1000-1500 in maintenance every few years.

That said I thought I might ask you gear heads why the superchargers in these PWC's are apparently so unreliable. Kawasaki makes some of the fastest EDIT supercharged /EDIT bikes around, and they are supposedly quite reliable. So why are their supercharged jet skis (which use a similar engine as their sport bikes) so unreliable?

FWIW I have considered other non-supercharged skis. They would be fine but they do not have the oomph of the supercharged versions.

 

[SpatiallyAware]

I don't know of any production super or turbocharged motorcycles. Every couple years someone leaks some blueprints, but it's never come to fruition on a mass produced bike. People stick turbos on the big kawi and hayabusa, but it's not a factory thing.

I don't know anything about PWC specifically. But, knowing how a supercharger works, they require tight tolerances. In a large 3+ liter motor it's not too terribly difficult.

In a 1300cc engine with a little tiny supercharger I imagine it would be tough to make a supercharger to those tolerances that lasts very long. Smaller things require smaller tolerances which tend to introduce greater wear.

Now, a supercharger sits in your intake tract. So if it fails catastrophically you're looking at bits and pieces of metal getting sucked into the motor.

 

[Sho'Nuff]

That makes sense. Thanks. PWC's tend to have small engines, though they can produce enormous horsepower. E.g., the Kawasaki 300X produces 300HP, which is almost frightening when you consider it only weighs ~1100lbs with a single rider.

 

[monkeydelmagico]

lemme guess, you've never put significant seat time on a jetski......... and now you want to do 80 on the water. good luck.

 

[Yuriman]

Not saying this will definitely be the case with you, but everyone I know who got a jet ski with the intention of riding it every weekend, did so for a few weekends, and then put it in the shed. A vast majority get taken out no more than 2-3x per year.

I don't imagine a supercharged 'ski would be an issue, as for most it's years before they hit the 100 hour mark.

 

[JulesMaximus]

I know this is a car oriented forum but I thought a post about personal water craft (PWC) would be ok. Mods please move if this is the wrong spot.

Long story short I am in the market for a new or used jet ski. Since this is a fairly substantial purchase I have been researching the heck out of the various models, engines, etc. I've come to the conclusion that I would like one of the supercharged models (e.g., Sea Doo RXPX, Kawasaki 300X, etc.), but I am very concerned about the reports I've been reading re: the reliability of supercharged jet skis. Most of the reports I've read say that the supercharger needs to be rebuilt at 100 hours, else major mechanical failure is likely to ensue (i.e., blown engine). For me that would mean that I would be looking at a supercharger rebuild every other year, as I would likely ride the ski 5-10 hours a week. That's ~$1000-1500 in maintenance every few years.

That said I thought I might ask you gear heads why the superchargers in these PWC's are apparently so unreliable. Kawasaki makes some of the fastest supercharged bikes around, and they are supposedly quite reliable. So why are their supercharged jet skis (which use a similar engine as their sport bikes) so unreliable?

FWIW I have considered other non-supercharged skis. They would be fine but they do not have the oomph of the supercharged versions.

They don't make a single bike with forced induction of any kind.

Have you ever ridden a supercharged jet ski? I've ridden some standard ones and they seemed to have plenty of power even with up to 3 people on them and could hit close to 50mph. Not sure why you'd want to go any faster than that unless you were racing it.

 

[SpatiallyAware]

lemme guess, you've never put significant seat time on a jetski......... and now you want to do 80 on the water. good luck.

+1

Jetskis can be dangerous. I'm very familiar with boats and water and I've almost knocked myself out on one just by acting a little stupid and not paying enough attention to the frequency of waves.

It strikes me as something similar to a motorcycle.. Start with a smaller used one, sell after a year or so and move up.

 

[Soccerman06]

If you think these will hit 80mph unmodded your out of your mind.


oh and yamaha has the more reliable supercharged models

 

[Insomniator]

Who rides a jetski 10 hours a week?

 

[LTC8K6]

Not saying this will definitely be the case with you, but everyone I know who got a jet ski with the intention of riding it every weekend, did so for a few weekends, and then put it in the shed. A vast majority get taken out no more than 2-3x per year.

I don't imagine a supercharged 'ski would be an issue, as for most it's years before they hit the 100 hour mark.

That could be at the heart of the reliability/longevity issues, if they actually exist.

 

[Sho'Nuff]

lemme guess, you've never put significant seat time on a jetski......... and now you want to do 80 on the water. good luck.

False. I have spent many, many hours on a jet ski. Probably about 300 hours in the saddle since 2002. Mostly on various skis owned by my relatives. None of those skis are supercharged, but my father in law's ski (a Honda Aquatrax) can get up to 60MPH when the lake is flat.

So . . . I am not a newbie when it comes to jet skis. Just wondering why the supercharged models seem to have a much higher mechanical failure rate than the non-supercharged models.

 

[Sho'Nuff]

Not saying this will definitely be the case with you, but everyone I know who got a jet ski with the intention of riding it every weekend, did so for a few weekends, and then put it in the shed. A vast majority get taken out no more than 2-3x per year.

I don't imagine a supercharged 'ski would be an issue, as for most it's years before they hit the 100 hour mark.

I have a seasonal campsite in Maine. We are there all except two weekends in the summer, and I ride a ski (with my son) each of those weekends for at least an hour or two. My father in law's ski has 300+ hours on it. Most of my relatives are well over 200 hours too.

 

[Sho'Nuff]

Who rides a jetski 10 hours a week?

On a typical weekend I will take a ski out 2-3x a day for a total of at least half an hour (1.5 hours per day). 16 week camping season = 32 weekend days. 32 x 1.5 hours = 48 hours a year. That does not include the week long vacation we take up there every year (spans 2 weekends and 5 weekdays), which adds 5 additional days (or 7.5 hours)

 

[monkeydelmagico]

False. I have spent many, many hours on a jet ski. Probably about 300 hours in the saddle since 2002. Mostly on various skis owned by my relatives. None of those skis are supercharged, but my father in law's ski (a Honda Aquatrax) can get up to 60MPH when the lake is flat.

So . . . I am not a newbie when it comes to jet skis. Just wondering why the supercharged models seem to have a much higher mechanical failure rate than the non-supercharged models.

My bad. Superchargers and turbos have more moving parts, tight tolerances, and, generally speaking, require strict maintenance schedules. Combine these factors into a very small space, add heat, and a marine environment and you have some very difficult engineering challenges.

As a former test rider for seadoo I would urge you to consider a yamaha

 

[Sho'Nuff]

They don't make a single bike with forced induction of any kind.

Have you ever ridden a supercharged jet ski? I've ridden some standard ones and they seemed to have plenty of power even with up to 3 people on them and could hit close to 50mph. Not sure why you'd want to go any faster than that unless you were racing it.

Sorry if what I said about the bikes was inaccurate. It was based on what I read on other forums. I have no experience with motorcycles so . . .

To answer your question - no, I have not ridden a supercharged jet ski.

Also, I do not need to go faster than 60 MPH. And upon consideration I would really prefer not to purchase a supercharged ski (I know this is inconsistent with my OP). I would actually prefer a non-supercharged model. The problem is I do not want to buy new and the vast majority of used skis I am seeing on craigslist are supercharged models that are nearing the 100 hour mark (supercharger rebuild).

 

[Sho'Nuff]

My bad. Superchargers and turbos have more moving parts, tight tolerances, and, generally speaking, require strict maintenance schedules. Combine these factors into a very small space, add heat, and a marine environment and you have some very difficult engineering challenges.

As a former test rider for seadoo I would urge you to consider a yamaha

No worries.

My concern with the Yamaha's is that they all (or at least the older models) seem to have the "rooster tail" design where water is shot up in a large plume behind the ski. That is just fine when the ski is just being used to speed around the lake, but in my experience it is extremely annoying when you are being towed behind the ski (on a tube, water skis, etc.). Getting pelted with water droplets at 20-30 MPH is not comfortable.

Also - what are your major concerns with Sea Doo? What should I look out for when considering a used one?

 

[JulesMaximus]

Sorry if what I said about the bikes was inaccurate. It was based on what I read on other forums. I have no experience with motorcycles so . . .

To answer your question - no, I have not ridden a supercharged jet ski.

Also, I do not need to go faster than 60 MPH. And upon consideration I would really prefer not to purchase a supercharged ski (I know this is inconsistent with my OP). I would actually prefer a non-supercharged model. The problem is I do not want to buy new and the vast majority of used skis I am seeing on craigslist are supercharged models that are nearing the 100 hour mark (supercharger rebuild).

Ok, that makes more sense then. I guess just wait until you find the right one. Shouldn't be too hard to find one with low hours. I'd imagine small watercraft are kind of like motorcycles. A lot of people buy them thinking they'll use them all the time and they end up sitting around most of the time until they get sold with relatively little use.

 

[monkeydelmagico]

No worries.

My concern with the Yamaha's is that they all (or at least the older models) seem to have the "rooster tail" design where water is shot up in a large plume behind the ski. That is just fine when the ski is just being used to speed around the lake, but in my experience it is extremely annoying when you are being towed behind the ski (on a tube, water skis, etc.). Getting pelted with water droplets at 20-30 MPH is not comfortable.

Also - what are your major concerns with Sea Doo? What should I look out for when considering a used one?

Google rooster tail delete/mod. It's a "feature" that can be defeated.

My main problem with Seadoo had more to do with the engineers blaming the test riders for problems rather than diagnosing. I was with the company when they were developing their 4 stroke engines.

As for Yamaha, I view their R&D as having more money and resources to do the job right. It doesn't hurt their reputation when almost all the rental companies use their boats too.

 

[JCH13]

Um... is it just me... or is the answer to this really simple?

Superchargers -> more parts, more power -> more failure points -> lower reliability.

Combine that with not having a suspension to isolate the engine from bumps/impacts like a motorcycle has, the high-moisture environment of watercraft, and the tendency to neglect maintenance on toys only used a few times per year and yeah... you'll have that.

 

[slag]

Who rides a jetski 10 hours a week?

Before I had kids, I did easily 10-15 hours a week in the summer. Standups are super fun!

Now my oldest is 14 and is wanting to learn so we are back in the market for some.

 

[slag]

Seadoo used ceramic washers in their supercharger which would break over time and get ingested into the intake. The fix was to use metal washers that would not break.

 

[JulesMaximus]

Google rooster tail delete/mod. It's a "feature" that can be defeated.

My main problem with Seadoo had more to do with the engineers blaming the test riders for problems rather than diagnosing. I was with the company when they were developing their 4 stroke engines.

As for Yamaha, I view their R&D as having more money and resources to do the job right. It doesn't hurt their reputation when almost all the rental companies use their boats too.

:thumbsup: I've rented a few of those.

 

[boomerang]

How about this? Two stroke motor has no oil sump and there is no provision for lubricating the bearings on the supercharger? Just a guess and probably a wrong one. I had a Pontiac (Buick maybe, it was a long time ago) with a supercharger and there was an oil reservoir built into it. The oil was supposed to be changed on a maintenance schedule so I see no reason a supercharger on a PWC couldn't be set up the same way.

 

[Dr. Detroit]

Since there seem to be an abundance of sit down skis at your camp - get yourself a stand up. Pretty steep learning curve but so much more fun than a sit down.

Everyone will appreciate the opportunity you give them to master a new craft.

Those 2004/5 SeaDoo 3D's always looked fun.....

 

[SearchMaster]

If you think these will hit 80mph unmodded your out of your mind.


oh and yamaha has the more reliable supercharged models

My brother-in-law has a pair of 300X's, and the top speed is limited to 67mph but it's supposed to be pretty easy to remove the governor to hit 80mph easily.

He's had them two years now and I can't say the reliability has been good. One of them wasn't running well much of last summer...he took them in for servicing a couple of weeks ago and I don't know what the diagnosis was on it. Also, the damn things absolutely suck down the gas. I think they have a 20 gallon tank and you can burn that in a couple of hours. They are ridiculously fast. Frankly my other brother-in-law has a ton more fun on his older skis because he jumps them with abandon