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Diesel vs 4 stroke outboard???

9K views 21 replies 13 participants last post by  coreywoodworking 
#1 ·
Hi again, need to pick the brains from those who have been there, done that.
I have a 26'' Chrysler sailboat w/ swing keel.I plan on taking it from Kenosha Wi.(Lake Michigan)through the great lakes, out the canal system (or St Lawrence??) to the I.C.W. & then to the Bahamas & points south.
My question is, I have on my boat now a 9.9 hp Yamaha 4 stroke outboard. I have the opportunity to purchase a used 9 hp yanmar diesel w/ trans. for about $1500. From what I can see it will cost me another $1000 in parts to install the diesel.
My S/O seems to think that the outboard will "wear out" getting to the Bahamas & that I should fork over the $$$ to do the diesel. What I am looking for is experienced honest opinions on the matter.
I''m not trying to prove anyone wrong or right, I would just like ideas before I make a decision that I can''t undo.
Thanks in advance!!!!

Larry C
 
#4 ·
I also have a 26 ft.boat and I debated the same question (inboard vs.outboard) when I purchased her. I opted for the inboard diesel because I knew that I would be doing some longer trips with her and the increased fuel range of the diesel would be beneficial. On my boat, I try to think of back up systems for most everything. Since I have a small dinghy I use with the boat, I decided to add a outboard stern bracket on her. If I were to have a major break down with my diesel, I could use the outboard off the dinghy in an urgent situation. Also, storing the outboard on the stern bracket makes it easier to put the outboad on the dinghy since it''s lower to the water. In my opinion, considering the type of trip you you are planning and the price of the inboard diesel I think you should install the diesel.
 
#5 ·
Hi,I have a PDQ catamaran with 2-9.9 yamahas.Of all PDQ,s built,about 3/4 or more are with OBs. The advantages are,ease of self maintanance,lifing when sailing,no shaft & log problems,no electrolosis problems,quiet. Deisels are usually very reliable,use less fuel,but are difficult to repair yourself,expensive if you can''t.I think going to that expense with a used engine is very risky."If it ain''t broke don''t fix it". At any given time there are 15-20 PDQs with OBs in the Bahamas& Carib.The other thing is,you will never recover that cost when you sell the boat.
Marc
 
#7 ·
If the boat has not been designed to support an inboard, you may put in about $7000 to redesign the hull and install stringers. Plus it probably won''t sail worth a crap. Might be cheaper on that size boat if you want inboard to just buy another boat with inboard. BTW...
a few years ago a Japanese man crossed the pacific with a Tohatsu powered launch. Treated properly the outboard will give you many years of service.
 
#9 ·
Not sure there is a correct answer. Having owned boats with both, in general, I would take the 4 stroke OB over the diesel. New outboards are VERY reliable and low maintenance. The 4 stroke Yammy is fairly fuel efficient, especially at 9.9.

However, it seems that you wish to make a very very long trip in a small boat that might require lengthy periods of motoring. In general diesels are the choice in this case. The price you mentioned makes me think you are thinking of a used diesel...

SO, my advice would be to stick with what you have and put the money towards gas for the trip. A used diesel can be very problematic. You have the up front costs and unknown costs should it break down in the middle of your trip. In addition, not knowing the boat, the above comments the inboards suitability for your boat my be significant. If ANYTHING happens to your OB during your trip, you can disconect it from you transom in seconds, lift it up yourself and carry it to a dealer (or the dumperster and get a new one for $2000).

Keep the outboard in the mid portion of its rpm range and you will be fine. Save the cash.
 
#11 ·
Your situation makes me think of all the people who replaced their Atomic 4''s with diesels, and the problems they had with the diesels not having as much torque as the older gas engine. This meant that instead of 6 knots with the gas, they got four with the diesel turning the same prop, simply because it couldn''t spin as fast. Perhaps newer diesels run at higher rpms and have more torque than before, but if not, this could be an expensive drag on your trip.
 
#20 ·
i want to clarify this statement.

diesels have MORE torque than gas.. torque is rotational force, not HP... for the same hp diesels have WAY more torque.

what has happened with these swap outs is that the rpm changes...
if you switch from an atomic 4 to a diesel, you will have to at the minimum have the prop re pitched.. maybe even an new different diameter prop...

a diesel inboard is the most reliable (other than electric) propulsion you can have. by their design they last longer.. they use a light oil for combustion. this in and of itself will help lubricate moving parts.

but i do agree that if your boat did not originally have an inboard... stick with the outboard.
 
#12 ·
After reading everyone’s message on your topic, I thought I add some more info to your difficult decision. I have a Columbia 26 MKII with a 2 stroke outboard. I don''t like it and I am envious of boats with 4 Strokes. 4 strokes are quiet and do not have a "smokey" exhaust like 2 strokes. I agree with everyone who said don''t install an inboard with out having an engine bed designed for your boat. But, I also wanted to as that Diesel fuel is somewhat safer to have aboard rather than Gasoline. Gasoline is many times more combustible than Diesel. However, if your gas is properly handled you won''t have a problem.

What I don''t like about outboards is their clumsy portable fuel tanks. They never seem to fit in compartments or they are sliding around. One time, on my previous boat, when sailing in some choppy seas, I decided to put the tank in the aft compartment. Even though the tank was sealed, it managed to leak before I got back to port. It made a huge mess, and stained the inside of the hull. But the worst thing was the fumes, my boat filled with them. This was very potentially dangerous. Ever since, the tank ALWAYS remains on lashed down the weather deck. It is very unsightly.

I plan to install an inboard fuel system for the outboard motor in my current boat. I am just trying to figure out the particulars with connecting the tank to the motor. I think I will use the existing rubber fuel line for the outboard connection, but I need to have a good connection for the tank end.
 
#13 ·
Hello

I am not exactly sure of your situation but if you are considering re-powering with an outboard and... would like to have a diesel... there are diesel outboards. Yanmar makes 27 and 36hp ob''s, not sure if there are other models. Might be a possible solution for you. Something worth checking into. Sorry I cannot be more specific.

Hope this helps.
 
#14 ·
Diesel Inboard vs Petrol Outboard



OK I don't know your boat but I do have experience of your problems (even if slightly secondhand). A close friend purchased a Westerly 28 fin keel sloop with a view to long distance cruising. (UK to the Antipodes). He did not want to pay for a watermaker and decided that removing the 36HP Volvo MD3B diesel would save a lot of weight. He reasoned that the weight saved would allow more drinking water to be carried and the plan was to use an outboard motor just for entering and leaving harbours. Unfortunately this was a bad mistake. OK the boat is principally a sailing boat but sometimes there is no wind! At other times the wind is coming head on which is a big problem in narrow channels. The new Honda 7.5HP outboard was OK up to a point but in heavy weather the prop leaves the water. The economy is not brilliant either. In the end he sold the outboard and re-installed a diesel in order to motor through the Panama canal. The new diesel was a 10HP Japanese single cylinder model with no balancer shaft. This would not have been my first choice to put it mildly but there were probably financial reasons. IMHO the flywheel is too small hence the motor is impossible for most people to hand-start and even the makers engineer cannot hand-start it. There was no balancer shaft and at certain revs the entire boat would vibrate, mast,rigging and all. It was important to run the engine either below or above the resonance band.

Jims next boat was a Hurley 27 (AKA Dockrell 27). Less grand than the Westerly but IMHO its Betamarine BZ13 (a twin) was impeccable, SMOOTH RUNNING, of course the previous owner paid a lot of money for that engine. I sailed (motored actually) round The Lizard on that boat doing Plymouth, Falmouth, Penzance. At times did hear the Beta race as the prop lost its grip whilst punching against wind and tide so I doubt whether an outboard could have done it. Even with diesel economy several imperial gallons were consumed and an outboard would have used double the amount. Two mishaps occurred on that trip. Firstly the pitching of the boat frayed through the cord supporting the radar reflector. It fell from the crosstrees and was blown backwards into the cockpit where it felled the skipper. The next mishap was a broken battery terminal. Cheap zinc alloy plated to look like brass! Luckily we had Mole grips (vise grip pliers) on board, but those fake brass battery terminals ought to be banned as they are a safety hazard.

Good Luck! but as always its horses for courses.
 
#17 ·
If the boat can take the inboard diesel without weeks and weeks of modification, then it would be diesel for me.
It will outlast any outboard, 2 or 3 times over, and storing gasoline aboard for any reasonable range will be difficult.
The diesel will use less fuel, has no spark ignition to get damp, and is a better set-up for heavier weather.
For me, it would be diesel.
 
#18 ·
Go Outboard do NOT redesign...

I have a 25' Morgan with a Yanmar and a 27' catalina with a Nissan 4 stroke, I have to pull the morgan every few months and scrape the prop with teh Morgan, when it's clean it's great but I would not redesign my Catalina to utilize the Yanmar, I like being able to pull the engine off in 60 seconds if I need service, for the money you put into redesign to support the Yanmar you can have a spare outboard...

JCL

;)
 
#19 ·
outboards cavitate (lift out of the water in rough water when you need them most) no matter how well they are mounted. on the plus side they run great and for hours on end, no where near the problems as 2strokes.

I love my Diesel inboard and don't think I'd ever want a boat without one. on a 26ft CB boat though, The question of where the inboard would go in relation to the cb trunk and the cb when it's up, engine access, engine cradle, batteries, then the controls, the shaft log, shaft, cutless bearing and strut, water lift muffler, raw water intake with strainer, diesel tank, tank plumbing, filter, pump, bilge access just to mention a few things.

Your taking a 26ft cb boat on the ocean? Hope you have the experiance for such a trip!
 
#21 ·
I'm elsewhere on Sailnet, asking "Am I nuts to ditch the diesel for an outboard?" and I'm following the collective advice to get to know the diesel. Still, I know the C26 (and envy your shallow draft K/CB) and you'd have to cut up a lot to fit a diesel. I once owned a Bristol 26 and 27, both with outboards and did a survey on the Bristol page. Of 35 replies, the conclusion was 6-8 HP, four-stroke, high-thrust prop (very important) and 25" shaft (also very important to keep prop low in a seaway.) Use the Garelick motor mount that hikes the engines 15" up and I think you'll be great. I'm headed for the Bahamas myself in 2012. Look for Nanagram, a Caliber 28
 
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