How many hours are too many hours ??

[Bathmagic]

Well this issue has been sold

The guys decided to keep the boat

So I'm back to looking at the 2007 with 396 hours

Thanks for your input and advice to everyone that posted

[glassywaters]

I know is AUS things are different. Especially pricing. What are the details on the low hour boat? I personally favor lower hours because they are easier to sell. Once you get to the 1,000 mark it kind of puts a black mark on the ride. Plus you kind of get free use out of the boat. You can go from 400-500 to 900 in 3-5 years and be in the same place you would be at the start with the higher hour boat. Given condition is the same....

[Bathmagic]

https://www.boatsales.com.au/boats/d...SSE-AD-5991947

This is the other one

[NautiqueJeff]

ZR6. Nice! The other one had an Excalibur. Still good, but the ZR6 is better!

[Luebowski]

Thats a nice a looking boat + great engine. $39K USD is about what it would go for, at least here in CA and you could probably make an offer for less.

[Nautiquehunter]

I read if you replaced the control box it fixed the issue but that was a random post somewhere so not sure if that's true. I do know it is a control box issue. I just can't imagine it's a hardware problem. Seems crazy to me that this isn't something they can resolve with a firmware update.

Nautique Hunter, How did you wire up the hour meter?

I bought a cheap hour meter off Amazon for $12. It is battery powered and has a wire that you wrap around the spark plug wire to detect when the engine is running.

Sent from my Pixel 3 XL using Tapatalk

I mounted the hour meter under the engine cover latch so no extra holes. 2 wires one to ignition hot and the other to ground.

[Sailfun]

Here's one way to think about it. Over the years, average speed in a car is something like 40 mph. At that average speed a car with 900 hours would have 36,000 miles on it. Would that concern you if you were buying used? I'd be more concerned with the maintenance records. Best of luck!

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That car at 40 MPH is using 30 to 50 HP or basically loafing. It’s not a very valid comparison. Boats and planes are similar in that they typically are using 60 to 75% of available power. Typical lifespan of a well maintained aircraft engine is 2000 hours before a overhual is needed. Boats run about the same. I suspect however with the newer heavier surf boats where the motors are run at 75 to 90% of available power a lot more engines will need rebuilding closer to 1000 hours. With the type of boat you are purchasing and the fact it seems to be well maintained I suspect you could count on another 1000 hours. At 50 hours a year that’s 20 years. Do get a compression check and prebuy done on the boat but don’t let the hours scare you.

[greggmck]

That car at 40 MPH is using 30 to 50 HP or basically loafing. It’s not a very valid comparison. Boats and planes are similar in that they typically are using 60 to 75% of available power. Typical lifespan of a well maintained aircraft engine is 2000 hours before a overhual is needed. Boats run about the same. I suspect however with the newer heavier surf boats where the motors are run at 75 to 90% of available power a lot more engines will need rebuilding closer to 1000 hours. With the type of boat you are purchasing and the fact it seems to be well maintained I suspect you could count on another 1000 hours. At 50 hours a year that’s 20 years. Do get a compression check and prebuy done on the boat but don’t let the hours scare you.

My Surf boat uses a 450 HP engine. This engine does not produce 30 to 50 HP running at 40 - 50 MPH in a car. It is over 200HP. Sure if you compare a Honda Civic to a Surf boat then the comparison about miles vs. hours may not be very useful. But compared to a vehicle with a similar sized engine the comparison provides a reasonable first order comparison.



I am also an experienced aircraft owner and Instrumented Rated pilot. TBO in an airplane is a very poor example. Aircraft engines are designed to produce maximum horsepower at about 2500 RPM. But most importantly TBO is determined not because the average engine has completely worn out, but rather because the goal for in flight engine failures is ZERO. TBO is a VERY conservative time limit where a rebuild is mandated to keep any airplanes from falling from the sky due to engine failure.

[Sailfun]

Aircraft engines are similar to boat engines in that they are required as I mentioned to put out very high HP most of their run time. Aircraft engines actually don’t make it to TBO more than about half the time. Your Corvette I can assure you is not using more than 50 HP to cruise at intermediate speeds. You are confusing what the engine is capable of at a specific RPM with what is actually needed. It’s simply physics.
edit: Did a little research and a car with average drag and rolling friction needs about 20HP to sustain 60 MPH.

[Steven@Bat]

2013 g23 bought in 2016 950 hours it still good now at 1200. Run hard wish I had kept it in better shap but it still runs fine

[ecoastkid]

I see the issue is now moot but I'll throw my opinion in for sake of discussion.

I saw somewhere that people compared the oil change frequency to car miles and I think it lines up with what I have been reading about the longevity of these motors. A Chevy pickup with the related motor has a oil change frequency of 5 or 6 k miles if you go by the computer telling you when to change it. If you perform the recommended change every 50 hours on our boats, you would have done 18 oil changes in that time. 18 oil changes x 5000 miles = 90000 miles....or the probably half life of a Chevy 6.0 before an overhaul might be needed because its worn. That lines up well with 2000 hours being the point where an overhaul would be considered.

I think the oil change idea takes in to account the different types of usage a boat and car motor experience. The manufacture engineers recommend those intervals for a reason.

[greggmck]

Aircraft engines are similar to boat engines in that they are required as I mentioned to put out very high HP most of their run time. Aircraft engines actually don’t make it to TBO more than about half the time. Your Corvette I can assure you is not using more than 50 HP to cruise at intermediate speeds. You are confusing what the engine is capable of at a specific RPM with what is actually needed. It's simply physics.
edit: Did a little research and a car with average drag and rolling friction needs about 20HP to sustain 60 MPH.

I always appreciate alternative opinions because they often introduce new ideas and expand my thinking. But there are some things that I don't think are being considered in your point of view.

You discount the idea that hours on a boat cannot be compared to car mileage because: "That car at 40 MPH is using 30 to 50 HP or basically loafing. It's not a very valid comparison."

Clearly just because a car AVERAGES 40 MPH over its lifetime it is not always, or even mostly doing 40 MPH on a level road and "loafing". An average of 40 MPH over the lifetime of an engine would include stop and go city driving, heavy traffic and high-speed highway driving, all of which would require the engine to output a significant amount of horsepower. If my V8 Pickup truck were not producing significant horsepower during daily driving why is my gas mileage only 13 MPG? If the engine were "loafing" any significant amount of time I would be getting 25 - 30 MPG like the indicator shows when I take my foot off the gas and coast, but clearly that does not happen very often. The engine is regularly under load and burning fuel to perform under that load.

Most V8 engines with proper maintenance can be expected to last for at least 100,000 miles before an engine or transmission rebuild is required and at about 40 MPH average speed this equates to 2500 hours of engine time.

I lived in Florida and for more than a decade I trained as a competitive water skier. This involved training 3-5 days a week and tournaments on the weekend during the season. It was not uncommon to put 500 hours per year on our boats. As President of the largest water ski club in the country with over 125 active skiers many of my friends also put in that much time on their boats each season. It would not be uncommon to visit Okeeheelee Park where we trained and find more than a few late model boats with over 2000 hours. And I don't remember anyone having to rebuild an engine with that much time. And this was constantly accelerating from idle to 36 MPH for a 16 second pass and stopping to shorten the rope each time. And even under this stressful stop and go load it was very possible to achieve 2500 hours on the engine before a rebuild was required. This also correlates well to 100,000 miles and 40 MPH on a car.

Your thinking that surf boats must also have shorter engine life is equally incorrect. E.g. I suspect however with the newer heavier surf boats where the motors are run at 75% to 90% of available power a lot more engines will need rebuilding closer to 1000 hours. First, when surfing the engines of properly design surf boats are not running anywhere close to 90% power. Moreover, surfing involves frequent stops and idling to pick up the rider. Finally, when surfing at 11.3 MPH I can turn off the speed control and accelerate to 36 MPH with full ballast. If the engine were running at 90% power where does all the extra power come from to accelerate the boat to 3 times surf speed???

Also, the logic that just because surf boat engines are doing more work they must fail sooner is misguided. Clearly if an older ski boat were loaded with 3,000lbs of ballast, a surf wedge and were used for regular surfing it would likely not last to 2500 hours. But a newer surf boat has an engine, 2:1 transmission and a propeller sized so that the while surfing the engine will run within normal operating limits. A properly maintained surf boat can easily last 2,000 hours plus. Visit any wake board or surf school in Florida or Arizona. You will find they regularly put 500 hours per year on the engines and they are not rebuilt after only two years.

Increased load alone does not mean an engine will require rebuild sooner. If that were true a Mazda Miata would have a higher total mileage before an engine rebuild than an over the road tractor trailer truck. In fact, a Miata might last 100K to 150K miles, while an over the road truck can be expected to last 500,000 to 700,000 miles before needing an engine rebuild. This can be achieved by the truck, even when pulling 10s of tons of load at constant highway speeds because the truck engine and transmission were also designed to allow that load to be hauled while maintaining normal operating range of the engine.

[Sailfun]

I don’t want to rehash everything but again it takes very little power to go 60 in a car. My 36Hp VW would go 80 on a cold day. As far as how hard a engine works surfing Malibu’s show you how much power you have left at any time. Even with a 450Hp motor I was maxed out at 10.8 with a heavy load. The boat would still do 38 mph with that load but only after you retracted the surf devices and got the boat on plane where power required is far lower. The same applies for a Nautique. You won’t get near 36 with the surf devices deployed.
As far as longevity of a motor there are lots of things that come into play. In ski school boats as well as training aircraft where engines are run every day longevity tends to be very good. Most training aircraft make it to TBO but aircraft flown once a month often need a top overhual at 800 hours. The single biggest determinant for engine life is the average percent power it is asked to produce. It’s not a straight line scale either. Engine life decreases faster on a percentage basis than the increase in power demands.
The Miata verses a tractor trailer is not a valid comparison since they are engineered to run far longer than cars.

[Neptune442]

Patiently waiting for Gregg to refute with more research, graphs, analytics, and complex engineering jargon