Diesel outboards

Discussion in 'Diesel Engines' started by Pericles, Jul 19, 2020.

  1. Mr Efficiency
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    Mr Efficiency Senior Member

    If they have to be re-built after 2000 hours, there is little appeal.
     
  2. fallguy
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    fallguy Senior Member

  3. KeithO
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    KeithO Senior Member

  4. KeithO
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    Location: Michigan

    KeithO Senior Member

    Canadian diesel vehicles are not subject to the same rules as the US or the EU, which is why Canadians have a lot more choices of diesel vehicles than we do, for now at least...
     
  5. brendan gardam
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    brendan gardam Senior Member

    have you thought about starting a new thread about aircraft and trucks. its a bit unfair to take over pericles thread the way you have. i will take your advice and put you on ignore too.
     
  6. brendan gardam
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    brendan gardam Senior Member

    you will never wear it out with normal use. flush it with freshwater and replace anodes on time of course, but you already know that.
     
  7. brendan gardam
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    brendan gardam Senior Member

    modern 4 strokes can and do go way beyond 2000 hrs. if you can keep the corrosion from destroying them. you can't compare them with 70's and 80's 2 strokes. but there are lots of 70's johnos still running around because they didn't succumb to corrosion but do need rebuilds like you say.
     
  8. Mr Efficiency
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    Mr Efficiency Senior Member

    I reckon faulty thermostats wrecked a lot of outboards prematurely, motors running below optimum temperature, wear out faster.
     
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  9. fallguy
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    fallguy Senior Member

    It is trailered and sits most a week at a time in fw. Never installed the anode.

    fw use only

    only had the voltage regulator fail; merc had it sitting on top of the em and they'd cook over time and stop charging right

    Not meaning to get away from the diesel ob discussion. Yanmar and Neander and even OXE all say they aren't really trying for the recreational markets.

    I ended up going with Yamaha 90hp vmax. The only recent pricing I found on the d111 was 30,000 Euros. That is $35k us. I paid about $9000 each for the 90s. That is $50,000 in fuel to make up.

    Originally, we had planned F70s for the vessel. But we had concerns about alternator outputs. So we moved to the 90s and they were available in 25", so we went to xl shaft to raise the powerhead. Those come in at 363 pounds plus a 22# lift plate vs 257. Iirc, the yanmar is 375 pounds. So, the Yanmar weight is comparable to the Yamaha vmax 90.

    I gave it about 3 days of thought because we do have diesel onboard for heating systems and diesel so much safer. In the end, I just could not make sense of the price. That $50k overage is about a third of the build cost of the whole boat.

    I genuinely wish they could get these prices down. I read somewhere these are not EPA approved. Does that mean they are sold here, but not playing by some rules? I don't know.

    until this thread, didn't know about the oxe..I did my research in 2016 for the build

    I checked and the 125hp is just too big a beast to consider. Some marketing hype suggests 750 hours to break even to gas. 750 hours at wot? Anyone know pricing on the oxe? At round figures of 750 hours and $5 fuel and 10 gph, that says 37,500$ and say double fuel economy is ?$19,000 more for the 125hp?

    I suppose these double crank engines are sort of like buying two engines.. my attitude is largely disappointment in the industry because the greatest threat to my vessel is fuel fire
     
    Last edited: Jul 28, 2020
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  10. Boatman1011
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    Boatman1011 Junior Member

    Getting away from the low Hp models, what about the new 300 hp models coming out? My original comment in this thread was directed at those models not the <100 Hp DTorque. The premium paid on a diesel inboard is about 2:1 vs a petrol; 300 Hp petrol sterndrive package is about $25k - $28k and the diesel package around $50k. From what I’ve read it will be the same for the diesel outboards; 300 Hp petrol $25k - $28k and the 300 Hp diesel OB’s will be around $55k. The 425 Hp Yamaha XTO is just south of $50k btw.
     
  11. fallguy
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    fallguy Senior Member

    I might have bought the dtorque for double the price. There is a small concern about more moving parts more to fail, but the fuel safety is pretty important; more so on longer range vessels. If your vessel can be further offshore; fire safety is more important. Of course, the alternative is eating rocks...I digress.

    I don't see the 300hp diesel competing with a 300 gas unless it wins on performance stunningly. Fuel economy and hp-torque to weight.
     
  12. brendan gardam
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    brendan gardam Senior Member

    How often have you heard of outboard powered boats burning, its pretty rare. I know of 3 boats that burnt to the waterline, 2 diesel gensets and 1 diesel engine. The only outboard boat I know that burnt was caused by welding near fuel breather. There are a lot of boats here that fish up to 180 km offshore chasing broadbill. They are almost all outboard powered with 400lt plus fuel tanks. None ever have problems.
     
  13. Boatman1011
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    Boatman1011 Junior Member

    “None ever have problems” is quite a broad statement? Research it and see what started the recent development of the more modern diesel outboard. It was a single fuel directive also aimed at operational safety to prevent the risk of carrying petrol.

    Mercury Racing developed for the U.S. Department of Defense the DSI Outboard, a two-stroke 3-liter V6 diesel that is spark ignited and runs on ultralow-sulfur fuel. The crash of a Navy ship in 1995 that resulted in a gasoline fire motivated the DoD to remove gasoline engines and fuel tanks from ships and develop safer alternatives. The DSI is available only to the military.”

    Capture.JPG
     
    Last edited: Jul 30, 2020
  14. Mr Efficiency
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    Mr Efficiency Senior Member

    What a load of bullship, worrying about carrying petrol on board, isn't in the top 100 likely problems, it is petrol fumes that cause the problems, in confined spaces, with a possible source of ignition. Petrol outboards don't answer those requirements. The German army in WW2 ran tanks fueled by petrol, the interior of a tank is a confined space, and people shooting all sorts of munitions into these vehicles, didn't translate into fire from petrol being high on their list of problems. If people are trying to flog diesel outboards as a cure to a fire risk, they are being disingenuous, and can only lead to the conclusion the products are short on merit as a viable alternative.
     
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  15. KeithO
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    KeithO Senior Member

    The US military has been doing a lot to move to a single fuel. Logistical support in all sorts of hostile places is why and it certainly wouldn't hurt if the fuel is less volatile. But I doubt it is because of a single or multiple accidents. Its just a huge pain in the butt to have to move different fuels around the world and on battlefields. The ships and planes carry stuff far more dangerous than fuel routinely, including nukes, ordinance, propellant for mortars and canon etc etc. There was a lot of government money spent in the 90s on multi fuel engines which included several companies making wankel engines that were diesel fueled and spark ignited. Then it all went dark and none of it is available on the civilian market, so I had no idea what happened.
     
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