Need engine rebuilt

majoma

Member
Oct 10, 2008
284
San Francisco
Boat Info
2000 340, V drive
Engines
Twin 7.4
My mechanic, after checking the compression of my starboard engines told me that I need the engine rebuilt. So now I am not sure on what to do. Have it done or try to sell the boat "as is" as a "mechanic special" at a discount and telling potential buyers that one engine needs to be rebuilt.
Did anyone ever went through this situation?
 
i went through this, last year. since it's so hard to sell ANY boat, much less one that needs $10k worth of work, it's a crap shoot. add to that the idea that you would be selling--or, more correctly, NOT selling--in November, and you are in that tough spot. i opted to rebuild and keep the boat. one of the big joys of boat ownership. but the good news is, i have a brand new engine, and a boat that is worth a few pennies more, though, even with a new motor, still tough to sell.
 
It’s a dilemma that I understand.
Unless you’re willing to take a rock bottom price, it will be hard to sell a boat that needs a motor.
Do you plan on staying in boating, or are you getting out of it?
If you stay in, does your current boat fit your needs for the foreseeable future?
What’s the overall condition of your boat other than the one bad motor?
When the starboard motor on my old boat went I decided that I liked the boat so much that I replaced both motors with brand new ones.
It was a relatively big investment considering the age of the boat, but the plan was to keep it for a long time.
The boat was in otherwise excellent shape, plus I had a potential buyer for the motor that was still good, so those things helped with my decision.
It wound up that I only kept the boat for 4 more seasons before deciding to go bigger. Had I known I was going to sell so soon I probably would have just replaced one motor.
No regrets though. I had 4 fantastic trouble free seasons with my old boat and it sold less than 24 hours after I put it up for sale.
 
Always the deal that what goes with one motor might well go on the other. Found that to be true flying small multi engin planes for years. More than once I was in the position of wondering as I looked out at my remaining operative power plant if the same wrench turner worked on both. If the vessel is yours in all respects; meaning you would stay with it for the long haul, then it's just antoher aspect of owning a boat. Would not wish having to make that choice but that's the crap shoot of boat ownership.
Kind of reminds one of the cable TV show " Love it or list it"
 
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I would never accept one mechanics opinion when condemning a motor. Are the motors fresh water cooled? How many hours on them? Could be just a top end reconditioning for 2-4k is all it needs.
 
Thank you for your comments. The boat is, generally, in very good condition but the mechanic found the compression on the starboard engine to be 110 psi in several cylinders and 125psi in the others. The port engine has compression of 155 psi in all cylinders.
 
Being within 10% is considered acceptable. Even tough one engine lower than the other. How does the engine run?
 
I agree with this, if i
With those #s, I would not be afraid of running the boat anyway you want. There are plenty of boats out there with those #s that are run and run hard. I would also be looking for 2nd opinion.
was looking to buy that boat, I would have concerns, but if I already owned it, I would still be running normally

when I bought my 380, 6 cylinders were 135/140 with the other 2 at 100, ran at factory speeds. I had the seller do the heads and now all 175ish (if I recall correctly)
 
The engine runs fine but I don't want to go over 2,500 RPM

What do you mean by "I don't want to go over 2,500 rpm? Do you mean the motor it won't go over 2,500rpm or you are reluctant to go over 2,500rpm. What rpm will the motor run at WOT?
 
I am concerned to go at high RPM. That engine has about 1,000 hrs and the mechanic told me that it might blow up at WOT. So, before I decided to do anything, (rebuild it or sell the boat) I will take it easy. My intention is to get a newer 340 (2004+).
 
I am concerned to go at high RPM. That engine has about 1,000 hrs and the mechanic told me that it might blow up at WOT. So, before I decided to do anything, (rebuild it or sell the boat) I will take it easy. My intention is to get a newer 340 (2004+).

if your intention is to replace your boat with a 2004 of the same size then I would seriously consider a total repower of your present boat.
If it’s in otherwise good shape you can probably repower for less than an upgrade will cost you and you’re going to wind up with a boat you know with brand new power as opposed to one you don’t know with 16 year old power.
 


if your intention is to replace your boat with a 2004 of the same size then I would seriously consider a total repower of your present boat.
If it’s in otherwise good shape you can probably repower for less than an upgrade will cost you and you’re going to wind up with a boat you know with brand new power as opposed to one you don’t know with 16 year old power.

I agree, given the overall choice, I prefer the 2000 version of the 340 over the 2003+

Just my opinion
 
IMHO you need a better mechanic. A compression test doesn't necessarily tell the whole story. What other diagnostics did he do? Did he do a leak down test? Did he check the valves and/or rings using the oil trick? Etc. Your compression numbers aren't crazy out of line. If the engine seems to run fine up to 2500 rpm, I would do some more digging.
 
I am concerned to go at high RPM. That engine has about 1,000 hrs and the mechanic told me that it might blow up at WOT. So, before I decided to do anything, (rebuild it or sell the boat) I will take it easy. My intention is to get a newer 340 (2004+).

You've got to be kidding. IT MIGHT BLOW UP!!!! I would run from that mechanic. He's trolling to make $$$. Take the boat out and see what rpms the engines will achieve at WOT. They will not blow up. 1000 hours does not mean the engines are at the end of their life. I've seen 454s run 3500 hours with the heads never being off. I would give that engine a good run for an hour with a few 2-3 minute sessions at WOT and then do a compression test while the engine is still warm. I bet the results will be much improved.
 
You’re mechanics opinion is suspect. Get a second opinion w a leak down test. Also, compression tests can vary depending on a number of factors.
 

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