Is it worth it.

[captchuck]

Been struggling with my 5.7 Volvo setup its the original motor in my 1984 25' seaway every time I think I've got her right I'm wrong I always make it home but sometimes its just plain old embarrassing on top of aggrevating when i have to mess with it at sea. I spent all last winter redoing the boat tanks, paint top and bottom, electric, cabin etc etc etc and now I just can't deal with it acting up anymore. I have replaced half the moveable parts on the engine and currently I need to replace the 400 raw water pump on it.
So the question is what is my best path...
A. Keep messing with it?
B. drop in a new gas motor try and keep the transmission?
C. By a used diesel around 200 hp which will prob have to include a new shaft etc?

Obviously this is an opinion based response. I'm a shop teacher so Its fair to say that im above average handy wise and therefore also use the boat quite a bit over the summer but prob for not for more than a dozen or so miles a day in the summer time. And in the spring and fall bass fishing once a week near 30 miles round trip.

 

[El Mar]

I'm a shop teacher so Its fair to say that im above average handy wise and therefore also use the boat quite a bit over the summer but prob for not for more than a dozen or so miles a day in the summer time. And in the spring and fall bass fishing once a week near 30 miles round trip.

Don't you mean Tech Ed.

I can't really say what's best for you, but glad to see another shop teacher around these parts. I've been at it 15 years now.

What keeps acting up???

 

[captchuck]

Tech Ed is right!
Other than the occasional replacement part which at this point I'm running out of parts to replace. At random the boat does not want to idle and occasionally even start. Never an issue when it's running and I've even had a mechanic on the boat just there's no telling when the problem will arise. I realize that it's curable sooner or later but it's more along the lines that after every few trips I'm turning around and fixing or fiddling with something.
And of course than there's my wife who does not trust the boat that I have dumped thousands into along with countless hours.

 

[El Mar]

Sounds fuel related, but if you give up everything you have found so far I'm sure the guys around here can help. I'm not very familiar with that particular motor.

How many hours on the motor?

 

[yanmar]

I'd be looking at the overall condition of the boat and addressing any problems that you may have before repowering . Considering the age of that engine i would be repowering . Cost , the amount of work that needs to be done and time would dictate weather its worth doing .

 

[Pedlyr]

I have a 350 Mercruiser in my Shamrock.

Do you have a carb? Points or electronic ignition? What about the gas you use. Ethanol blends now used can sometimes gum up seals. Plus it can soak up a lot of water.

I work with diesels and would love to have one. From a cost standpoint ONLY, it doesn't make sense for me. It takes a long time to recover the extra money for a conversion. If that is what you want in a boat, fine.

This place might help for a longblock or a conversion if that is what you want.

Marine Engines Transmissions New and remanufactured

 

[captchuck]

Boat has new tanks, filters, lines I've checked the stone filter it just comes and goes. Electronic distributor

 

[Pedlyr]

Do you have anti siphon valves on the gas tanks? How are the vents? I would try burning new gas out of a remote tank to see what that does. How is the fuel pump? Mechanical? Electric? Can you get a vacum on it? Doesn't sound like you have a carburetor, but you could have issues there.

You could also be sucking air somewhere, like around the intake manifold. Some guys use WD-40 sprayed around to look for leaks. Or a vacum gauge on the intake can help.

Any backfiring? Timing good? RPM's good at top end? How is the ignition switch and connections? Good voltage? A bad ground can be a bitch sometimes.

Just my 2 cents.......trying to help here. Sometimes simplest problems are the hardest to find.

 

[captchuck]

Fuel i can almost positively say is not it since everything is new and I swapped out the filter last week and the gas in it was crystal clear.
I do have a carb which when all is good is tuned in just right and I tightened down on it to make sure air was not getting below it. Boat runs great at all speeds just plain old does not always want to idle.
One hint might be that everytime I put the boat in nuetral after running somewhere the idle is initially high and slowly works its way back down tio where it should be.

 

[Pedlyr]

Things I would look at......

Make sure your throttle linkage is not sticking and properly adjusted. This has happened to me before.

Fuel pump pressure should be between 3 - 7 PSI. Should not be fuel in rupture tube.

Make sure in-line fuel filter screen at carb is good.

Make sure carb is "level" and that the wedge spacer plate (if needed) is correct. No air leaks here either.

You can always mess with the idle screws, but usually that works right away.

Has the carb been rebuilt? For about $150 these guys will rebuild your carb. I have had 3 done by them. Use a USPS flat rate box. Takes about a week or less. They do great work.

Hobbs Carburetor Shop in Pelham | Hobbs Carburetor Shop (603) 635-2415 & 108 Windham Rd, Pelham, NH 03076 | <Automotive/Repair & Service/All> - Yahoo! US Local

Keep the faith!

 

[captchuck]

OK so I need to put my foot in my mouth here, had some water in my fuel ended up replacing my vents with vents that had inner elbows I could swing up as i believe it was saltwater (there was white crystals if you will floating around in what I dumped out of the filter) I will run the boat for a few hours and check the filter again before I go replacing the water pump rebuilding the carb etc.. (even though its running like crap at the moment)

 

[El Mar]

Check your fill plate too, o-ring might be gone or damaged.

 

[steveinak]

I had problems with spray running into my fuel vents so i made some vent shields from some plastic pipe, once i installed these all my water problems went away.

 

[captchuck]

Replaced the Orin's on my fills earlier in the season because I thought the same thing. The new vents I installed go up before they turn back down towards the tanks so I'm hoping that does the trick.

 

[Sailorgp]

Your 5.7 Volvo is a Chevy engine. I have an 1991 Indmar 5.7 in my 26' Sisu. Same basic engine. I had a peculiar problem with my engine this past spring caused by the mechanical advance in the distributor not returning to it's proper timing when idling. A little shot of oil on the advance mechanism fixed it. The symptom is that it would run fine above 1500 rpm or so but wouldn't idle. It was intermitent.

 

[Pedlyr]

One of my gas tank vent hoses liked to form a trap or a dip in the bight. It was just enough to let a restriction develop. I switched to vents in the fill cap like this. It was a bitch finding that one.

PERKO Inc. - Fills & Tank Vents - Vented Fuel Fill for 2 Inch Hose (Marinium)

 

[captchuck]

Your 5.7 Volvo is a Chevy engine. I have an 1991 Indmar 5.7 in my 26' Sisu. Same basic engine. I had a peculiar problem with my engine this past spring caused by the mechanical advance in the distributor not returning to it's proper timing when idling. A little shot of oil on the advance mechanism fixed it. The symptom is that it would run fine above 1500 rpm or so but wouldn't idle. It was intermitent.

Was this on an electronic distributor?

 

[Sailorgp]

Yes my engine has an electronic distributor (no points). However, there could be several types of electronic distributors on the 5.7 liter V-8's. Mine is what's known as a Prestolite distributor.

 

[Sailorgp]

The advance mechanism is beneath the ignition module. It's located in the base of the distributor. If you take the distributor cap off and twist/wiggle the rotor back and forth you'll feel some rotational movement. That movement is the advance mechansism allowing the rotor to turn a few degrees.

 

[captchuck]

I have a Mallory I will def take a look in there today