Compression Test Number 2004 5.7 350 MAG 260 Sundancer ... Real or Fake???

Hi Guys,

- So i had my 260DA listed with a broker from my marina and he had a potential buyer they left 10% deposit and had scheduled a survey and a sea trial. . .
I should make some early key pointers
-Had 391 hours last time i checked
-Had less then 1/4 of gas in engine
-Never had any issues with engine

- The day of the survey and sea trial i get a call from my broker and he goes to me
"Hey we are having some issues the boat wont turn more then 4000 rpms and it should turn up 4600 to 5000 rpms thats what says on the engine cover"

I have not had the time or nice weather to take the boat out so for about a month the boat was not moved from its slip so they tough it was lots of build up on the bottom they took out the boat from the water to inspect the hull and i authorized to power wash the bottom of the boat and clean props...

"Broker and Surveyor went on a ride again and now they got up to 4100 rmps"
I got a call back and they are saying the boat needs Tune up (I've only had this boat since April and i'm selling it to go bigger 300Da)

I said what the hell if i sell it or not tune is needed and idk when it was last time this engine had a tune up so i authorized a tune up... . Spark plugs cap filters etc...

I went down to the marina this Saturday and there is my broker he says to me Nick we have a bigger problem then a tune up. . so they did a compression test on your engine and here are the numbers:

Compression Test
Year 2004
Engine 350 MAG
Cylinder 1 - 180
Cylinder 2 - 175
Cylinder 3 - 165 > They are saying Cylinder 3 & 6 are too low and is a problem
Cylinder 4 - 185
Cylinder 5 - 180
Cylinder 6 - 160 > > They are saying Cylinder 3 & 6 are too low and is a problem
Cylinder 7 - 190
Cylinder 8 - 185

Here when things get interesting Broker says he talked to mechanic and also broker use to be a mechanic so he know "a lot" about engines. . . Looks like there is some water in there but it should be an issue but in order to sell this no matter who looks at it this issue will show on the survey so we need to fix it and its going to cost ~$2500

I said i wanted to talk to the mechanic he came by and when i asked again how much this will cost me he had no number in mind he just said $300 for each head give or take plus a day and half of labor and that's when broker said yeah like i said around $2500...
I told them ill think about it.

So i went back to the boat started it let it warm up and i was gonna go on a ride.
did my checks as usual and saw the following...
-Hours 391
-Gas less than 1/4
So i said to my self how did they go on a sea trial twice and it take about 20 min of no wake zone to get to the bay 20 min no wake zone to get back in thats 40 min alone plus sea trial 20 min. minimum? that's an hour why does my meter show 391 why does my gas is still at 1/4 ???? hmmmmm !!!!!! LIES from broker and mechanics?

I put gas in and took the boat out i opened it up WOT i did 4690 rpms with one more person on board. less than 1/2 a tank of gas. . .
I met up and tied up with some of my buddies and one of them is a mechanic so i told him what had happened and he said lets go for a ride. . . i let him drive the boat he even opened it up now it was 4 of us on board WOT i boat still did 4690 rpms

So there are few things that i am scratching my head here about
1. I don't think they did compression test and if they did the idiot probably did once and wrote done those numbers.
2. They want to scam me for the Head job for $2500
3. How come my engine hours are the same as before.
4. Boat had no gas for a full sea trial apparently they went out twice....

Sorry for the lengthy post but i did not wan to miss anything out. . . The potential buyer back out because of this =/ .......

Any thoughts???

Maybe the wrong boats got a tune up at your expense and is missing some fuel?

@Thornton69 lol who knows anything is possible with these guys. . .

Maybe the broker found another, more expensive (more commission) boat that the buyer wanted and is looking for a way out of your deal?

The biggest indictment is that your boat ran 4600+ RPM's with no issue, completely contradicting what you were told. I would ask for there to be another sea trial with you on board and see what they say.

I would hire my own mechanic and pay for your own engine survey and give it to perspective buyers and let them decide if they want their own.

@copb8tx its possible good thinking let me check his website to see if they removed anything...

My first question of the broker would be who did the survey and I want to speak with him as well as read the report .
I expect this broker is a crook so record every conversation. Don't allow him or his people to touch your boat. Fire him and with a report from your own surveyor in hand take him to court

@Handsome Transom I am waiting on his call....

But does anyone know if those compression numbers are right or wrong?

In a perfect world, we look for the lowest to be within 10% of the highest. So your spread of 190 - 160 falls at about 15%. If there was indeed an engine driveability issue, then I would look closer as those two holes by doing a leak down test to see where the compression is going.

Sounds like the engine is running fine, so I would not get bent out of shape with those numbers.

Lastly, you do not know how flawed that test was. Engine warm, cold, good, cranking RPM, did they run those two low cylinder again just to double check? Did they squirt a little oil in those cylinder and redo the test?

185 would be a healthy number. Your 2 low ones are middle cylinders which would indicate water from the exhaust did some damage. The engine could last quite a while as is, but it is hurt a bit. I would discount the boat a bit to reflect that. There will be buyers that won't be as concerned with those numbers. Make sure you are there for any more sea trials, they probably didn't trim the drive up.

@Wylie_Tunes Engine runs like a baby not a single choke or miss-fire or alarm
i think the test they did was on a cold engine. i will be heading down this week and do the test with a second mechanic.

@scoflaw according to broker trim was all the way up. . . but then again i dont think they ever took the boat our b.c my hour meter is the same. . .

Blueone said:

I would hire my own mechanic and pay for your own engine survey and give it to perspective buyers and let them decide if they want their own.

Click to expand...

+1

Those compression numbers don't scare me in any way, shape or form. Given the scenario, and the information presented, I wouldn't trust that the compression test was done (a) correctly and (b) on a warmed up engine.

The RPM's you got - approaching 5,000RPM's is perfect for your 350MAG. IF they did take the boat out, whomever ran it probably didn't know how to properly trim it for max speed.

Thanks @Lazy Daze "Dennis" you've always have give me well information on this boat way before i even bough it. Thanks for all the info.

Your welcome, Nick. Based on the info given, I think it may be safe to say that you should just quietly move on to another broker. On the assumption that you want to stay at your current marina, you probably don't want to burn any bridges... at least not yet Just tell them you're taking it off the market to think about what you want to do (do you have a "minimum fee" in your contract?). Or... take one of them out for a ride with you and show them what the boat does and don't say anything... see what they say.

Call the broker and reschedule the sea trial with the buyer and that you will be on the boat. Then you operate the boat to open water and nail it and prove the WOT rpms are within spec. Then ask the broker: "Any questions?"

BTW, get the keys out of the boat and keep them in your pocket.

With a light load you should be able to hit 5K. It's the buyer you have to convince that those numbers are nothing to be concerned about, not yourself or members here. This is an example how a motor begins to go South.
Compression test hot or cold does not matter much, it didn't effect the 190 cylinder. The fact that it's 2 middle cylinders that tells the tale. Myself, being a savvy buyer, with the information presented would know the engine will need work in the future.

@Lazy Daze i have a video of me going from no wake to WOT it wont let me post it here ill upload it on a different site and post the link here in few min. there is no minimum fee there is 10% fee if he sells it or if i sell it with in the 3 months contract but i am ready to burn that contract and tell him i dont want him to sell it bc instead of him doing all possibilities to sell it such as hey listen it needs tune do you wanna do it or do we take $300 of the price and etc. . .

@fwebster good thinking but idk if that buyer is still interested. . .

@scoflaw true but any boat engine needs work sooner or later. . its not about the work here its about the mis honest information . . i dont think those numbers are right something is not adding up. . .

One more thing about the RPM'S and the trimming. He says 4100, you say 4600, important part here is, was the SOG increasing from 41 to 46. You could rev that thing to the moon if you trim high enough but no good unless the speed also increases.