What do boat hours mean?

[brettmainer]

I was looking at my truck display today. 112,000 miles and 2735 hours. 41 miles per hour. Does that mean my 2014 200 that has 300 hours is equivalent to 12,000 miles? Our last club boat was flipped with 3500 hours. Equivalent to 140,000 miles or so at 41miles per hour. I'd say the boat was a bit more used than that, but not by too much. In my opinion, it was more like a 2005 truck with 200,000 miles...quite used but still plenty of life left. Is a boat hour equivalent to 40 miles or maybe 60 miles? What is the general consensus?

[ozski]

I think hours are a rough measure at best, there are so many different types of hours. I've seen boats with 400 well maintained hours that look like new. And the reverse.. My boat is 10 years old and very low hours, its a bit weathered inside. In a few months a ski school boat can rack up hundreds of hours and be like new or the other.

[Orlando76]

I just bought a 93 Ski Nautique. 485 hours and it seems true. Upholstery looks like the day it left the factory, not a nick in the rub rail. Engine so clean you could eat off it. Vibrates like a jack rabbit on steroids. Bad cylinder heads and bad rings on #6. Ideally I wanted a 93 with 800 or so. It's all in how you use it/frequency of use/maintenance.... And in that order imo. I was always told 100 hours could equal 12,000 miles.

[DCinVA]

I agree with the comments above. In general boat engines have to work harder to push a boat through the water than a car engine does to push a rolling car down the road. But todays engines have so much power that I am no longer convinced that this makes a huge difference. Also the marine environment can be rather harsh on the electronic components of an engine. A lot also depends on the type of use. When I was younger, and played a lot on the river, I usually ran my boats a lot at full throttle (WFO), whereas today I am more focused on 34 MPH slalom. I think skiers typically take pretty good care of their boats. As others have said, I have seen ski boats with thousands of hours on them and still running strong, but I have also seen boats with a few hundred hours on them that are trashed.

I have always said buying a boat can be a crap shoot.

If I were to equate hours to miles, I would be more inclined to use 60 for a marine engine.

 

Dave

[Andre]

From when we get up to dropping at the other end takes about 30-32 seconds.

We then rest for 30 to 45 seconds.

So i think at least half the time on my engine is idling time.

Converting boat hours in miles is tricky...

[LeonL]

Jody or someone else who is knowledgeable can give a more accurate input, but I've heard that a download of ECM info indicates that a slalom boat is closer to 80% + idle time.

[Orlando76]

But that 20% is hard throttle.

[webbdawg99]

Perception is reality....even if it's not. I think the perception of the market is about 100 miles per hour. Very few people would consider buying a boat with more than 1000 hours or a car with more than 100,000 miles. These 2 numbers seem to be highly correlated.

[Horton]

34mph is less revs than 36 mph / different for every model and prop

 

revs = wear

 

A boat owned by a trick skier boat owned by 36 mph skier

 

[GAJ0004]

My boat has 1750 hours on it, but I have seen some boats with less than half that are not in as good condition as mine. Once I get the coaming pads and engine cover reskinned it will look almost brand new again. I will take that since my boat is now 21 years old.

 

[SailorDave17]

Be careful only looking at the hour meter, I do believe some boats were manufactured without hour meters, but they can be mounted later, might not be the true hours. Aside from that, it is about how well the boat has been taken care of and how "hard" those hours were on the boat. In my opinion anyway...

[Waternut]

Until we start installing rev counters, I think of hours as a warning sign. More like BMI (body mass index) than mileage on a car. If you have 10% body fat and lift weights multiple times a week but BMI says you're nearly obese, it probably doesn't mean you're unhealthy. However, if BMI says you're obese and you eat a box of fried chicken every night while watching tv, you might wanna look into it.

 

300 hours on a 15 year old boat makes me think it was never used and there is a good chance it was neglected (visual comparison of the boat can usually confirm). 700 hours on a 5 year old boat sounds high but that's about what the rate I put hours on my boat. Basically if the engine pulls strong has under 800 hours, I probably wouldn't think twice but any boat significantly over 1000 hours, I'd probably do a compression check on the engine before buying it...just to be sure.

 

I personally shut the boat off between skiers/boarders. I average 1-1.5 hours of run time in a 3 hours session. I have been out with people who leave the boat running the full 3 hours and I've skied with people who shut the boat off after every single pass through the course.

[hemlock]

I'm not a mechanic (but an enthusiast mechanic), but it's hard to compare ski boat engines to car engines.

We always run in one gear, which means to me the engine is always on the hot side.

(which I think can be good for an engine)

If you change your oil in the required intervals and run the proper gas the engine should

last for thousands of hours.

Also, the air that the engine takes in is way cleaner than you'll find on any road.

 

I think with proper maintenance, tow boat engines will outlast anything else.

:smiley:

 

[RichardDoane]

average speed is about 20 mph, so 1000 hours is not that many miles compared to an automotive application, when I sold the 92 MC 205 in 2010 with 1450 hours it still ran perfect, and I would expect it to go 4000 hours

[swc5150]

It's great when you can run a diacom on the newer engine. My boat has 671 hours, with roughly 80% at idle. Even as a baller, you'd be amazed how many idle hours you're logging.

 

Hey @Waternut is that an F18 in your profile pic? Taking my daughter to see the Blue Angels today, for an All-American 4th of July celebration:) They've been rehearsing over our house this week, and it's been just awesome to watch.

[dancin4]

B) Great discussion...I sold my 1997 Malibu Eschelon in 2013 with 2900 hours...running as strong as the day I bought it, (Merc Black Scorpion 315HP fuel injection.) We left the engine running when we changed skiers, for the first 10 years we had it, (it was a promo boat.) I changed the oil most of the time with synthetic oil (50 hours), and it came out clean (not black.) The only issues we had was with electrical type things (engine hour meter module.) We did use the boat for kids skiing and trick/swivel for at least 2/3 of the pulls. Only really course skied with it the last couple of years.

We replaced the boat only to get a smaller wake and zero off control.

My ski friend (80 years old,) had better luck with his 1972 Mastercraft....31 years original engine and transmission!) His hour meter went out after 3 times around! It also was a promo boat from Tommy Bartlett's....His engine was the Ford Windsor 351 and mine was the Chevy 5.7L.

I wonder if SKIDIM or another engine re-builder house can chime in.

[Phil2360]

I'll 2nd 100mph.

 

My 4.0Litre falcon does 160km/h @ 3100 rpm.

We slalom at around 3000 behind a 400 Chev.

 

The car is only facing rolling resistance & air drag, so the boats gotta be working a whole heap harder.

 

Other side of the coin is that over 15 years and 800+ hours (Yes it's an old tub), fuel consumption has always averaged out at 11.0 Litres/hour per season.

 

Maybe the hours/consumption would be of better help in a rough translation of hours to miles.

 

 

[E_T]

You have to just about compare it to a drag car. Idle to flat out to idle again. Some guys can make a motor last along time. It's all related to components quality and build quality.

[boarditup]

Hour meters are good for comparision to other boats of a similar type and use. I use my boat for wakesurfing mostly (yes, I know this is a slalom forum, but that is what the kids like). My hours are at 2,950 rpms with a big load. That is very different than a slalom boat or any car.

 

A lot of the difference in wear is due to how the engine was originally broken in, the number of oil-starved cold starts, and obviously the maintenance (specifically oil changes).

[Texas6]

The difference for you is that you put a tremendous amount of stress on the all of the components between the motor and the water hauling around all of that extra weight

[skibumm]

Hours are the first gauge. I am pushing 3000 hours and it runs great. It has lost a little power over 23 years but still fires up every time and can hold 36 in a course. Now I will admit to being the odd man out on this as my boat looks as good as it did 23 years ago. If I were looking at boats I would get one with higher hours that was in better shape than lower hours. I would then have something to negotiate with as well

[Than_Bogan]

@Waternut Insightful comparison to BMI, which can extremely misleading, but has some potential value if understood for what it is.

 

Also, perception-wise I'll join the chorus of folks saying 100mph conversion.

[DW]

I think a better analysis would be climbing a fairly steep hill rather than going 100 mph. Drag force for an average car going 100 mph is really only 250 lbs of aero force. Given the density of water and the wetted surface area, probably a better estimate would be around 500 lbs given the throttle position needed to drag a skier across the lake at 34/36 mph. But 100 mph sounds impressive, just like 1000 hours "sounds" like a lot at first blush.

[Onside135]

For those of you who have had them done, what are your dealers/mechanics charging for a full up diatom report with the hours/rpm breakdowns?