Slim hope being frustrated

[friendcal]

OK, so my "freeze" plugs were blown out this spring. I know, bad sign. But I have more time than money right now, so I thought I would replace them and see if maybe, just maybe, the plugs just blew out and the block didn't crack.

Anywho, I got the new plugs in...and the engine won't start. Actually, it does start, it just won't run longer than a second or two. Once the gas is burned off from the initial prime, it dies. I'm suspecting a fuel supply problem. Obviously, I get some fuel, so I'm guessing that the problem is not in a clogged filter. That makes me suspect the fuel pump.

The manual (#25) says I should have an electric fuel pump, but I can tell you for sure that what I think is the fuel pump (the fuel lines run to it!) doesn't look like the picture and there are no electric connections. So I'm wondering what makes the fuel pump pump. Pictures online look more like what I have and it looks like there is a "lever" sticking into the block. But what good will that do?

The boat is a 17' 1990 Rinker open bow. It has a 4.3l Mercruiser engine, I/O.

If nothing else, I am learning about my boat and how it works!

 

[achris]

Re: Slim hope being frustrated

Hey friendcal, Post the serial number of the engine and I can check which pump you have...

You are right, manual #25 does call out an electric pump. That's because it covers years 1998 to 2001. If the engine in the boat is the same as the boat, and that can only be confirmed by the serial number of the engine, then you should be using manual #07....

Chris....

 

[geneseo1911]

Re: Slim hope being frustrated

The lever rides on an eccentric on the camshaft, which makes it move up and down. The other end is attached to a diaphragm that pumps the fuel. I highly doubt a boat that age would have an electric fuel pump. I assume it is carbureted? If it has been some time since it last ran, it is likely that the jets in the carb are plugged with "varnish" or dried up gas, and will need to be disassembled and cleaned.

 

[friendcal]

Re: Slim hope being frustrated

Hey friendcal, Post the serial number of the engine and I can check which pump you have...

You are right, manual #25 does call out an electric pump. That's because it covers years 1998 to 2001. If the engine in the boat is the same as the boat, and that can only be confirmed by the serial number of the engine, then you should be using manual #07....

Chris....

Indeed, Chris, indeed. I found manual #7 and geneseo1911 gave me some good information as well. Soooo, next week I get to learn how to tear apart the carb! I guess I better order a gasket kit.

BTW, how soon would the water show up in the oil? If I just continue to start this and let it run for its' 5 seconds with the water on the muffs, could I start it 30 times (?) and find my oil getting milky? I don't see a crack on the outside of the block, so if it's cracked, I'm thinking it would be internal.

 

[bajaunderground]

Re: Slim hope being frustrated

Friendcal...having just gone through the idea of freeze plugs only...I cannot assure you that the block is cracked, but I'd be willing to bet? Here's what mine looked like once I got the heads off!


BTW, even with internal cracking I was able to get the motor to start (after at least a 5 year hiatus) and run...New short block at the very least...I ordered mine yesterday $1,076.67 (Ford 302)?! I bid good luck to you!

~Brett

 

[SangerDX]

Re: Slim hope being frustrated

I would do a compression test (fairly cheap guage you plug in to an empty spark plug hole) on each cylinder and see if the engine is worth messing with; if that checks out then worry about fuel pressure.

 

[achris]

Re: Slim hope being frustrated

I would do a compression test (fairly cheap guage you plug in to an empty spark plug hole) on each cylinder and see if the engine is worth messing with; if that checks out then worry about fuel pressure.

I believe the first order of business should be to determine if the engine is capable of being saved, and that would only be by pressure testing the engine block/heads... If the block is cracked, the party is well and truly over...

Chris.....

 

[84EdH]

Re: Slim hope being frustrated

Agree with Chris. Pressure test block through cooling system. Cylinder compression could be perfect and still have a cracked block.

 

[friendcal]

Re: Slim hope being frustrated

Agree with Chris. Pressure test block through cooling system. Cylinder compression could be perfect and still have a cracked block.

That sounds reasonable. I will figure out how to do that, then. I would imagine it is just a matter of attaching air to the engine side of the water intake and then sealing off the exits.

 

[Walt T]

Re: Slim hope being frustrated

INope. It'll blow out the risers and out the drive. Fill it with water through the t stat housing you have gingerly removed and see if you can see water leaking. Let it sit a day or two then check the oil.

 

[84EdH]

Re: Slim hope being frustrated

drain the cooling system, block the hoses going to the exhaust manifolds, this stops pressure from getting to manifolds, risers and exhaust pipe. rig up a pressure guage on the raw water hose going to the thermostat, put 10lbs psi of air in see if it holds. if pressure drops, listen for leaks.

DonS link from Adults only section: http://forums.iboats.com/mercruiser-i-o-inboard-engines-outdrives/water-your-oil-369864.html