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30' Blackfin

3K views 13 replies 8 participants last post by  sourdo 
#1 · (Edited)
Here is one of my bigger tows. Not sure what it weighs, but it's a heavy boat. 76 miles to deliver, EVIC showed 16.7 mpg. Even my buddy that went with me said it towed better than his Silverado 3/4 ton gas truck!
 

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#2 ·
My other "Diesel" moving a 26' boat around my yard, the Blackfin is just behind it. 2008 Arctic Cat 700 cc Lombardini 2 cylinder that I turbocharged and intercooled. Weighs about 1,000 lbs. Another Italian diesel in an American made vehicle!
 

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#4 ·
Not so sure it's all that heavy. Surprised it's an I/O with inboard motor and outdrive. They work OK for fresh water usage. Salt water use flat out destroys the things, no matter how hard some swear they work. Outboard manufacturers do a lot of re-power "specials" on I/O's tried in salt water.

Guessing that tow is not over your tow limit. The boat has rather low gunnel height and no topside structure. Should have been a lengthy but easy tow. Glad your experience was positive.
 
#8 ·
Vern - Good guess. Towable for short and flat terrain. This is a model they no longer make.

HOWIE - ... that Mercruiser outdrive. Actually all of the major outdrive units fail in a saltwater environment. Before even getting into the details always remember that those outdrives have a large rubber boot that flexes as it moves. If that rather flimsy rubber boot tears, the boat flat out sinks. It happens frequently. The reliability of all those parts, many touted as stainless and resistant, is very poor around salt water. Corrosion builds mostly inside from increased galvanic action. Marina mechanics earn a living dealing with and replacing those things on newbies bringing their boats to saltwater areas.

Short visits OK. Long term usage is a near total failure. That's why you see saltwater boats with one, two, three and even four outboards on them. They work and their coolant design is very resistant to galvanic corrosion with proper anodes and lower-unit construction. They are most always FLUSHED with fresh water after each usage. Not so easy to do with inboard engines and outdrives.

Now the engine in an I/O could have two different cooling systems. Most traditional for freshwater is raw-water cooling. Water in - water out. Not a problem in fresh water. Put one in saltwater and you have that going through the engine. You don't want to know.

The other coolant for inboards is to have a closed coolant system for the engine and a radiator/heat exchanger exposed to that saltwater cooling outside the engine. Made properly, that works way better. The racing boats you see throwing all that raw water out are not made for longevity. Just the cost of doing business.

Good question.
Seems strange that Mercury can make an outboard that handles the salt water and chooses not to make an outdrive that will. I agree that fresh water cooling of the engine is mandatory in salt water. My Volvo diesel inboards have them here even in fresh water. They don't make them a different way and that is fine.
 
#10 ·
Seems strange that Mercury can make an outboard that handles the salt water and chooses not to make an outdrive that will. I agree that fresh water cooling of the engine is mandatory in salt water. My Volvo diesel inboards have them here even in fresh water. They don't make them a different way and that is fine.
Sure would disagree that they "Choose" to make an outdrive that does not handle salt environment. The probably don't care as it lasts long enough to make it out of warranty, normally. There is a good reason Mercury motors are referred to as boat anchors.

As for other companies, like Volvo, that make outdrives. Same crap. Friend Brian Hecker trashed his volvo outdrive just last year on his 30 ft. he had maybe two, even maybe three different Volvo outdrives on his boat. Enough of that failure. Today he built a new transom and has been running twin Suzuki 250 outboards. Expensive change but worth it.

Most of the boats with I?O's are smaller boats - say 21 ft and under. Do know of a 24 ft. Calcutta Kat with twin outdrives. He was pulled at the marina about two weeks ago for maybe the third time. Outdrive trouble. Know one was replaced a couple years ago. Maybe more. I do not follow all the troubles of that drive system he has had in the 5 years of its' existence.

Sure there may be some I/O's that last a bit. Maybe they have real low hours? My current twin outboards have just over 2,000 hours on them. They are 2004 models. If I had I/O's I would not have that boat. Before that I had outboards for more than a decade and no issues with major hours. Before than an I/O from Mercury. Most of that usage, but not all, was fresh water. It still was trouble from the git go to the end with many repairs and one replacement. Avoid IO's at all costs. Just having the gas motor inside the boat is a fume danger you should never have to deal with.

Avoid I/O's.
 
#6 · (Edited)
That Blackfin makes your truck look small. :D. Can you do a lil research and find out what it weighs? Wild eyed guess between 8 & 9k.

Certainly the 3/4 was heavier & stiffer than the 1/2 but I bet to the 8 speed ED pulled it better than the 6.0. Some air bags and only 10 percent on the tongue even at 9k would have good weight on the steers especially with two guys in the front seat. Somewhere on here I have pics of towing a boat & weight slips. Think it was about a 9k load between the boat & stuff in the bed. 15k CGVW.
 
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#9 ·
While I'm not a Mercruiser guy, I have a customer with one of those 26's with 350 Chevy and Mercruiser Bravo IO. Owner has worn out 3- 350's, IO still works great, commercial lobster boat. My brother has one with Volvo Duoprop IO 225 hp V6 Chevy. Not a big IO guy, Mercruiser Alpha 1's are not suitable for a work boat imho. You can check out my company web site <northernbayboats.com> Built a lot of 36 and 38 foot models. Biggest motor so far was a 38 with a 1200 hp MAN. Top speed was 54 mph. BTW, the owner of the Blackfin, thinks it weighs around 7,500 lbs, trailer was fairly heavy, and tongue weight was very heavy, Towed like a dream, no sway or hobby horsing. Very pleased. He offered me a job hauling bait with my Ram, probably will try it. Fresh water cooling in IO's wearas OB's are always cooled by salt water . Also Volvo, Mercruiser, Steyr and Yanmar make Diesel sterndrives. Mercruiser may actually use the Ecodiesel 3L at 270 HP. I have had good luck with Volvo IO'S in salt water, same with Mercruiser Bravos. Weak link is typically the cast iron exhaust manifolds. Volvo has a better idea with salt water cooling pump, on front of motor, not in the outdrive.
 
#12 ·
Of course all outdrives have sacrificial anodes. What breaks on the outdrives is shift mechanisms, , hydraulic systems, internal gearings, water passages the corrode, boots that tear and leak, oil seals that don't, gear sets that trash and more. Very unreliable.

Also something fun is the old OMC outdrives could be listen out of the water. The newer ones not so much. People stick them in the sand and tear off the skegs because they do not lift way up to clear obstructions. Then they suck sand and other debris into the ports, tearing up the impellers, blobbing the intake ports and cause overheat damage.

What should happen and what does happen are two different things.

Oh - 10 gag grouper this morning in just 2 hours of fishing. Up to 104 into the boat since June 1st.
 
#14 ·
Of course all outdrives have sacrificial anodes. What breaks on the outdrives is shift mechanisms, , hydraulic systems, internal gearings, water passages the corrode, boots that tear and leak, oil seals that don't, gear sets that trash and more. Very unreliable.

Also something fun is the old OMC outdrives could be listen (sp lifted?) out of the water. The newer ones not so much. People stick them in the sand and tear off the skegs because they do not lift way up to clear obstructions. Then they suck sand and other debris into the ports, tearing up the impellers, blobbing the intake ports and cause overheat damage.

What should happen and what does happen are two different things.

Oh - 10 gag grouper this morning in just 2 hours of fishing. Up to 104 into the boat since June 1st.
I assume a typo and you meant "lifted"?

I had one of those OMC 'lectric shift POS's back in the 80's. I got pretty good on floating my boat onto the grid, pull the outdrive off, get it fixed, put it back on till the next time it busted. Breaking props from logs was common. Once I hit a rock at 20 mph, that one about gave me a heart attack.

So one day it was time to sell it, oh joy, oh joy. The buyer and I went down to the docks where I kept my boat, a 24 ft Seabird, made in Hialeah, Florida. It had the nicest wave crashing bow.

But back to the story, I had been well versed on what happens when the sea water pump in the outdrive would fail. The rubber boots directing the exhaust would melt without the cooling water, making lots of noise, and thus ending the days fishing.

So this guy I sold the boat too, were down at the dock. The OMC drive would completely come out of the water. And I told this dipshit several times what happens when you start the engine with the outdrive in the air, the impeller (it's in the shop manual) will melt in as little as 15 seconds if dry.

Three days later he shows up, all pissed off with this story about having to be towed in, out with his family, bla, bla. When he mentioned the melted exhaust elbows I already knew what happened. I got him calmed down a bit and let him talk on, and then he mentions of all the racket when he first started up the motor, ran it for a couple of minutes (his words) before he, and he's laughing, hahaha, that he forgot to lower the outdrive before starting.

Now it was my turn, I laid into him about his failure to lower the drive. " You dumbass!", "I told you several times what would happen if you started that engine with the drive out of the water" as I admonished him. With a very sheepish look, he apologized for being such an asshole (for a minute I thought it was going to be a fist fight! He was really pissed off!)

"What do I do now?" he asks. I explained about the "grid" and its use. To those landlubbers, a grid made of wood timbers, is below high tide, but above low tide, where you float your boat on at high, when the tide goes out you can work on the hull or outdrive while on the grid. He needed to take the drive off and take it to the boat mechanic and get it fixed.

Boats are a lot of fun, but they can get you in trouble, big trouble.

Oh, nice haul on the groupers. How are they for table fare?
 
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