Am I being taken

[Steveo]

Let me start by saying I know only enough about boats to be dangerous but what I am being told by my mechanic seems suspicious and I wanted the forum’s opinion.

Was out cruising around and my engine just quits. I thought that I might have just run out of gas because I had just replaced my gas gauge and thought it might not be reading correctly. Get boat towed back to the dock, put gas in and still nothing. Engine turns over but won’t fire. I call my mechanic and he tells me two things. (Just for reference I have a 25 year old Mercruiser I/O)

First, he says when that engine runs out of gas it isn’t a simple matter of putting more gas in and starting her up again. You need to go through all sorts of gyrations, like start-up spray in the carburetor, making sure gas is in all the lines (?), and other stuff. I thought aren’t boat engine just like car engines in that the fuel pump makes sure the gas is pumped throughout the system. So I ask him to come take a look to see if he could get it running. (I was not there when he came so I couldn’t see what he did)

He calls me and says it wasn’t out of gas but that the engine “wasn’t getting spark” and that it could be the starter or coil, he would have to test further. I thought engines don’t need the starter and coil to run do they, just to start. The engine was running fine when it quit. He calls back couple hours later and says “it was electronics”, couldn’t get any more explanation then “electronics”, other than “and the bill is $560.” I’m thinking how much electronics can a 25 year old engine have (being the dumbie that I am when I hear electronics I think computers, circuit boards, etc.). Now, I will ask to see the “parts” that he replaced but do both explanations/comments he made (run out of gas and electronics) seem reasonable.

I’d appreciate the expert’s opinions. Thank you so much.

BTW: this is local mechanic not part of dealer or marina but I don’t want to give name.

[ITD]

Need more description of parts replaced. While the engine doesn't need the starter to continue running, it does require electronics. A 25 yo engine was produced around 1988, electronic ignitions and early computer control was being used then. The electronic ignition and some type of coil(s) must fire on every power stroke for the engine to run. No spark, no run. Sounds like the mechanic did a good job and the price is probably reasonable unless the fix took him 2 minutes. Again, need more info, need to know what parts were replaced and how much time he charged.

[Dave R]

Some engines, like mine, require that the fuel deliver system be primed if it ever runs out. The fuel pump will not do it on its own. I carry a spare spin on fuel filter in a plastic Maxwell House coffee "can" and a small bottle of stabilized gasoline in my boat in case I need to change the filter.

[BroadHopper]

It is definitely the electronic. I have a 1988 454 Magnum with 640 hrs. The only thing I had to replace were the spark plug, wires and distributor cap. The starter has nothing to do with the 'sparks'. It turns the motor over so that it will start.
If the starter won't turn the motor and you have no spark, it sounds like a dead battery. I never had a battery that lasted more than 7 years.
If you ran the motor dry, usually the fuel pump will fill the carburetor up again. Same with fuel injection. If the fuel lines were dry for a significant length of time, well the gas/ethanol can turn into a turpentine mess.
In 1988 the 'Thunderbolt' ignition does have a CDI 'capacitive discharge ignition' module that looks like a black box with fins. It is not a microprocessor like a computer.
I have replaced the coil with a Jacobs and gap the plugs to .5. Significant improvement in the ignition and the skipping is gone.
I had to replace the fuel tank, fuel hoses and carburetor because of ethanol 4 years ago. Been running great since. I do winterized the boat with an empty tank since the replacement.
I am blessed with the same mechanic for over 30 years! :D

[NoBozo]

Some engines, like mine, require that the fuel deliver system be primed if it ever runs out. The fuel pump will not do it on its own. I carry a spare spin on fuel filter in a plastic Maxwell House coffee "can" and a small bottle of stabilized gasoline in my boat in case I need to change the filter.

I'm afraid I have never heard this in my 70 years about a gas engine.

However, when a Diesel runs out of fuel, you have to bleed the injectors to get the air out. It's easy enough to do, as the Yanmar diesel I had had bleed valves built in to do it. :look: NB

[NoBozo]

I would look at the Fuel Pump itself... AND the small Filter that is INSIDE the HEX shaped fuel line connector, where it enters the carb. It's easy enough to do in five minutes or less. :) NB

EDIT: Some of us are more fortunate than others in being able to do most of our own work, and it is always cheaper.

[Blue Thunder]

I would need more info as well as others have said. Broadhopper is right on the so called "thunderbolt" ignition box. It looks very similar to the Ford EEC boxes of the 80's. If that failed you would have been SOL. It was in many mid 80's Mercruisers including my 85 Liberator. It wouldn't suprise me at all to see it cost upwards of $400.

BT

[Dave R]

I'm afraid I have never heard this in my 70 years about a gas engine.

However, when a Diesel runs out of fuel, you have to bleed the injectors to get the air out. It's easy enough to do, as the Yanmar diesel I had had bleed valves built in to do it. :look: NB

Yeah, I was pretty shocked when I could not get it to run the first time I changed the fuel filter. The fuel pump draws fuel from the tank, through the fuel filter and then pressurizes it for the MPI system. The "brains" of the system allows the fuel pump to run for a few seconds when you first turn the key on, then the pump shuts off and presumable turns on again while cranking the engine. It does not hold the vacuum to the fuel tank well enough to fill the filter, no matter how many times I cycle the key on and off and letting the engine crank for a long time is not good for the starter or the batteries. If I pour a few ounces of gas in the filter before installing it, it fires right up and runs perfectly. From what I've read on line, this problem is pretty common and is likely a function of the boat design more than the engine.

[NoBozo]

Yeah, I was pretty shocked when I could not get it to run the first time I changed the fuel filter. The fuel pump draws fuel from the tank, through the fuel filter and then pressurizes it for the MPI system. The "brains" of the system allows the fuel pump to run for a few seconds when you first turn the key on, then the pump shuts off and presumable turns on again while cranking the engine. It does not hold the vacuum to the fuel tank well enough to fill the filter, no matter how many times I cycle the key on and off and letting the engine crank for a long time is not good for the starter or the batteries. If I pour a few ounces of gas in the filter before installing it, it fires right up and runs perfectly. From what I've read on line, this problem is pretty common and is likely a function of the boat design more than the engine.

I think the OP said his engine was 25 years old. My 1986 "MCM 260" (5.7L GM V8) has a mechanical fuel pump supplying a 4 barrel carb. I've never worked on fuel injected so I can't comment there. I think for the Mercruiser years 1986-1994, ONLY the Gen II 4.3L V6 had an electric fuel pump. No fuel injection. :look: NB


EDIT: Like somebody else said..maybe we need more info..like what engine...:look:

The trouble is if a boat owner doesn't know much about engines he is totally at the Mercy of the "Mechanic".....

[jrc]

....EDIT: Some of us are more fortunate than others in being able to do most of our own work, and it is always cheaper.

It's only cheaper if your time is free. My work time cost more than a typical mechanic and my leisure time is priceless. For some of us an honest and good mechanic is worth his weight in gold.

I've had a car run out of gas and not start up easily after refueling. The crap at the bottom of the tank can clog filters, even pre-ethanol.

Even on an older boat the electronic ignition modules can go, $560 is more than I would expect but I haven't repaired a 25 year old engine in 20 years and that was a car..

[NoBozo]

For some of us an honest and good mechanic is worth his weight in gold.

Even on an older boat the electronic ignition modules can go, $560 is more than I would expect but I haven't repaired a 25 year old engine in 20 years and that was a car..

My FREE time is free. I don't charge anyone (or myself) for my FREE time. When I am on vacation that time is FREE. I have on ocassion spent a great part of my vacation on Winni..replacing an exhaust manifold and a riser. My boat gets used maybe 15 hours a year. When you USE IT..That is the most likely time it will fail. I accept that.

The point here is...I KNOW how to do it. MOST people DON'T..and they PAY DEARLY for that lack of knowledge..Don't you agree..?? :look: NB

[NoBozo]

For some of us an honest and good mechanic is worth his weight in gold...

I TOTALLY Agree. BUT: HOW will you know if this is an Honest and Good mechanic IF you don't know something about engines yourself and can make a judgement on their work....?? Just wondering.:look: NB