Water seeping into the hull...help

[elcapitanjim]

I recently bought a LARSON ALL AMERICAN 190, with a 4.3L MerCruiser. Year of manufacture 1989. This boat runs great! Starts easy and maneuvers extremely well. My issue is with water seeping into the hull, after 4 to 4 1/2 hours of navigating at various speeds, I notice a lot of water getting in. Example, this Sunday I took it out and my automatic bilge quit working, I guess the float got stuck with possible junk inside the hull cavity. I took her out for the day and removed the plug. About 4 to maybe 6 gallons of water came out. Is this normal? The previous owner said he had it thoroughly checked by his mechanic, and could not find anything. Where is the most obvious place to look? I'm thinking the exhaust manifolds? What do you guys think?
Any help is appreciated.

El Capitan

 

[alldodge]

I recently bought a LARSON ALL AMERICAN 190, with a 4.3L MerCruiser. Year of manufacture 1989. This boat runs great! Starts easy and maneuvers extremely well. My issue is with water seeping into the hull, after 4 to 4 1/2 hours of navigating at various speeds, I notice a lot of water getting in. Example, this Sunday I took it out and my automatic bilge quit working, I guess the float got stuck with possible junk inside the hull cavity. I took her out for the day and removed the plug. About 4 to maybe 6 gallons of water came out. Is this normal? The previous owner said he had it thoroughly checked by his mechanic, and could not find anything. Where is the most obvious place to look? I'm thinking the exhaust manifolds? What do you guys think?
Any help is appreciated.

El Capitan

No not normal, with that much water entering in one afternoon you should be able to see from where. Dry the bilge off, then put the boat in the water and start watching. If nothing happens after a bit start the engine and watch some more, it should not take long

 

[Chris1956]

You should easily see water leaking from the manifolds and water circulation pump. The other obvious leak points on MerCruiser are driveshaft bellows, the large waterhose from the block to the water circulation pump, and to the manifolds and risers and shiftshaft bellows.

 

[Bondo]

I recently bought a LARSON ALL AMERICAN 190, with a 4.3L MerCruiser. Year of manufacture 1989. This boat runs great! Starts easy and maneuvers extremely well. My issue is with water seeping into the hull, after 4 to 4 1/2 hours of navigating at various speeds, I notice a lot of water getting in. Example, this Sunday I took it out and my automatic bilge quit working, I guess the float got stuck with possible junk inside the hull cavity. I took her out for the day and removed the plug. About 4 to maybe 6 gallons of water came out. Is this normal? The previous owner said he had it thoroughly checked by his mechanic, and could not find anything. Where is the most obvious place to look? I'm thinking the exhaust manifolds? What do you guys think?
Any help is appreciated.

El Capitan

Ayuh,..... Welcome Aboard,.... As noted above, Nope, it ain't normal,......

I take it ya got it on a wagon,..??
If so,....
Run it on the hose, 'n see if it's the motor's coolin' system, or a driveline/ hull leak,....

 

[BRICH1260]

I wouldn`t get too far away from the ramp with that much water coming in until you have fixed the problem. It`s got to be the engine, drive bellows or thru hulls if your boat has any. You`ll find it, just keep looking.

 

[crb478]

Crank it on the hose and see if the motor leaks while running. If not drop it in the water and look for leaks. If you still can't find it try filling the hull with water while in the driveway and see if you can see any water leaking out.

 

[Barramundi NQ]

If it's an engine cooling system leak filling the boat with water will eliminate the hull's water-tightness. Check the engine on muffs or on the trailer at the ramp to see where the water is coming from. If it's not the engine then test the hull by filling with water.

 

[Grub54891]

I'm not a fan of filling the boat with water,to easy to dunk the starter and low electrical stuff that should not get wet. I've always found any leak by running on muffs,then running running in the lake. A carefull inspection of the bellows and drive components should get ya there.

 

[tpenfield]

With a boat of that age, check the transom area around the outdrive as well as the mentioned engine possibilities.

 

[elcapitanjim]

Thanks to all for the advice. I will follow what you guys suggest and get back to you with results.

 

[elcapitanjim]

Thanks to all for the advice. I will follow what you guys suggest and get back to you with results.

 

[pops1940]

I had an older boat with a similar leak in the transom area. After verifing the location, I pulled the engine, removed the outdrive, and found out that the outer tramsom plate was actually eaten through with corrosin. I could push a screwdriver thru it with almost no force. I replaced the outer transom plate, problem solved. Hope yours is not this bad.

 

[hungupthespikes]

Sitting/drifting/docked no leaks, underway we got a very slow, but steady leak that drove me crazy. Has to be the motor/exhaust right??? Wrong, just bad/loose 1/4-20 bolts on the boat's grounding plate. Replaced and sealed, :triumphant:
huts

 

[elcapitanjim]

Thanks everyone, I found the leak when I was winterizing the Merc 4.3. Leak is caused by the water entering through the "rubber boots" on the "exhaust elbow" just behind the engine, by the transom wall. Both sides leak water into the bilge. When I would rev up the engine you could see the water seeping in from between the metal pipe and the boot, so I either have to tighten the clamps, or if they continue to leak after tightening, then I guess I have to replace the boots.

 

[thumpar]

Has it ever been run without water? That can cause the rubber parts to burn up. It may just be a loose clamp but if it was run without water you will need to check your flappers also.