Hour Question on BlueWater 7.4 Inboard motors on a 33 ft Dancer

[Sal0458]

I am looking at a 96 sundancer 33 ft - with BlueWater inboard 7.4 motors has 1000 hours on the motors. The current owner said to ask anyone that owns a SeaRay these PARTICULAR motors (BLUE Water) should last up to atleast 2500 hours CAN ANYONE CONFIRM THIS?

 

[larrytbull]

i have about 1200 hours on my 95 330 and still running strong

 

[Sal0458]

does 2500 hours on these motors sound correct

 

[Sal0458]

does 2500 hours sound correct life expectancy on these motors?

 

[LTD.330]

As with everything it is the maintenance. Does the seller have documented records of all of the maintenance performed on the engines?

Frankly, I've never heard of gasoline marine engines lasting 2500 hours before a rebuild. I've been told a well maintained motor has a life expectancy around 1500 hours before it needs to be rebuilt.

 

[bahamabreisus]

Our 42 DA had 7.4s 1600 hrs no problems. All in the records, get them. If not available compression tests will tell alot

 

[larrytbull]

when i bought my boat with 900 hours on it, surveyor gave me same # approx 2500 hours. but really as the other guys are saying, it is a combo of a couple of things, #1 maintenance
#2 how much is the engine used
if engines sit idle and do not run for long length of time i would be more concerned since engine is not getting proper lube

 

[Quint4]

I expect to get way more than 1500 hrs out of my Bluewater 5.7s.

I treat them very good.

 

[Jimmy Buoy]

A friend of mine has an early 90's 35' Express and its Merc 454's have over 3000 hrs. The compression is getting a bit low now, but they still run great. Obviously well maintained, but usually run @1200 rpm long distances. The boat has been piloted from Ontario to the Gulf of Mexico and as far South as Venezuela (they were gone for 6yrs). One tranny got saltwater intrusion from a shot cooler while on the trip, but no issues with the 454's. (closed cooling was added prior to the trip)

 

[northern]

We have 2200 hours. Used to burn 1 QT oil oevert 100 hours. Switched to Shell Rotella and the last 100 hours it did not use much. Power is the same top RPM is the same and so is speed.
No idea what we will end up with for hours. Am hoping for 3500

 

[RollerCoastr]

The problem with hour meters is that they tell us nothing other than how many hours the engines have run. That's close to useless, and sometimes, worse than useless: downright misleading.

Hours at least make some sense on generators because of the consistent RPM, but even then, Total Fuel Burn would tell even more.

A 7.4 can certainly go to 2500 hours, and even double that. They can also fail before 250. My neighbor's diesels failed before they saw 300 and 400 hours. I guess I should mention that they were decades old, overloaded, overheated and had neglected cooling systems... (but DANG the previous owners thought they had found a "great LOW-HOUR boat"!)

 

[testlab]

I have a 96 330DA with 7.4L Bluewater engines with V-drives and closed cooling (full systems). They have around 1000 hours on them now and I am expecting at least twice that since the compression is excellent and I use preventative maintenance to head off problems.

As said above the way they are operated is more important than the hours. I always allow mine to start at the lowest rpm possible and they are warmed up before placed under significant load. Mine have a minimum WOT of 4000 and we run them 70% of the time below 2000 and the rest around 3000 (giving us 22 kts).

Hard acceleration and high power settings kills engines, so if a boat is used for skiing or water sports then expect less life from the engine. The biggest killer by far on these engines seems to be lack of cooling system and exhaust system maintenance, leading to water damaged cylinders. Lack of use is also as bad as abuse.

 

[xravenx]

Mine had about 1125 hrs on them when one failed last fall, BTW they were RAW water cooled

 

[Bodkin Creek George]

I agree that PM is everything to these gas motors. Remember that everytime we run these gas boats it's like running your car up a mountain. The most important question other than the maint records is when were the manifolds changed last. When buying a boat of that vintage you must always consider the possibility of a re-power and use that as leaverage in your bid. Just my 2 cents.
George