Outboard Engines

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I decided to fix an outboard on my boat for the time-being. I've had the inboard diesel spinning over and it fired once but I had to redo some of the wiring. Then I discovered the outdrive needs seeing to as the wood that buffers the propeller area is rotten.
If anyone knows about outboards, I just put a deposit down on a Mariner 2 stroke (a gas-guzzling motor). However, I want to steer using a tiller and don't plan to remove my inboard engine, rather the outboard will hang over to the left at the stern, not central.
The plan is to drive the same as you would a small boat, sitting at the back and turning the tiller.
Anyone have an outboard boat engine who knows something about them?

How big a boat and how deep is the transom? Will the shaft be long enough to allow for steering, tilting ,and still putting the prop in the water? Is the tiller arm long enough to allow you to comfortabley sit and steer? Can you attach the outboard to a jack plate to allow you to raise and lower it if needed? You can also attach the outboard to the outdrive via a steering linkage and steer it that way without a tiller.

The boat is about 25 feet by six feet beam. The outboard itself comes with a clamp I could fit on the back ledge of my boat quite easily. Engine length seems about right for the boat.
I have a feeling I may have to set up an alternative gear and throttle lever somehow and obtain cables for that purpose.

How big a boat and how deep is the transom? Will the shaft be long enough to allow for steering, tilting ,and still putting the prop in the water? Is the tiller arm long enough to allow you to comfortabley sit and steer? Can you attach the outboard to a jack plate to allow you to raise and lower it if needed? You can also attach the outboard to the outdrive via a steering linkage and steer it that way without a tiller.

The boat is about 25 feet by six feet beam. The outboard itself comes with a clamp I could fit on the back ledge of my boat quite easily. Engine length seems about right for the boat.
I have a feeling I may have to set up an alternative gear and throttle lever somehow and obtain cables for that purpose.Carrera - Make sure you have the leg in deep enough not to allow cavitation. Which Mariner did you get? The small ones have no reverse gear, but have 360 degree rotation to achieve the same thing. The small ones are fairly fuel-efficient.
Fitting it on a displacement canal boat may make changing the prop pitch a worthwhile venture. Some Chandlers will let you try 2nd hand props to test for the best option. Your boat's own prop is probably bigger and pitched for lower rpm than your outboard's one is. Bear this in mind when trying to maneuver the beast with the little fella. When I pulled the diesel engine out of our 28' deep-keeled yacht years ago for a rebuild, I dropped an old 9.9hp Mariner of the stern, It was OK for a little bit of extra control when coming up on a mooring, but not much use for going anywhere. I eventually took it off and put it back on the Zodiac where it belonged, focusing on improving my sailing skills instead.
A lot of tinny owners down here in Oz fit a small length of pvc pipe over the throttle to extend the tiller, allowing them to stand further forward whilst trolling. There is a solution to (nearly) every problem. Look at it...have beer...look at it again.

Phew, my uncle would go crazy if I removed my inboard diesel.
Let me tell you something: In my geographical zone, you can find a mechanic to service a traditional Beta Marine or Lister diesel inboard or any type of outboard engine.
However, when it comes to a marinized vehicle engine like I have, forget it. There isn't a single mechanic over here who has a clue since the vehicle mechanics don't know how to deal with a modified engine and marine mechanics are clueless when it comes to Volkswagon.
I had no option but to study engineering myself and read up on Volkswagon diesels. So far, I managed to wire up the starter motor and modify the fuel system.
At any rate, an outboard is an easy option while I work on the inboard. 2 strokes are light and simple and you can get these engines serviced quite easily.
The Mariner in question is 5 horse-power and 2 stroke.

Carrera - Make sure you have the leg in deep enough not to allow cavitation. Which Mariner did you get? The small ones have no reverse gear, but have 360 degree rotation to achieve the same thing. The small ones are fairly fuel-efficient.
Fitting it on a displacement canal boat may make changing the prop pitch a worthwhile venture. Some Chandlers will let you try 2nd hand props to test for the best option. Your boat's own prop is probably bigger and pitched for lower rpm than your outboard's one is. Bear this in mind when trying to maneuver the beast with the little fella. When I pulled the diesel engine out of our 28' deep-keeled yacht years ago for a rebuild, I dropped an old 9.9hp Mariner of the stern, It was OK for a little bit of extra control when coming up on a mooring, but not much use for going anywhere. I eventually took it off and put it back on the Zodiac where it belonged, focusing on improving my sailing skills instead.
A lot of tinny owners down here in Oz fit a small length of pvc pipe over the throttle to extend the tiller, allowing them to stand further forward whilst trolling. There is a solution to (nearly) every problem. Look at it...have beer...look at it again.

What VW diesel? IDI or TDI? There are plenty of VW diesels used in non-automotive applications like generators (they have great torque at 1500-1800 RPM, making them great for AC) and pumps.

They have been around for 30 years so their isn't too much that is secret on the IDIs. But the TDIs are a different story as their electronic injection controls are not well understood outside of the VW dealerships.

The injection systems are Bosch and they should be able to help. If you want to DIY, it won't require an engineering degree, just a few factory manuals and a modest collection of tools. Far less than purchase of a new outboard.

Mariner is a mercury design.I have rebuilt a couple of outboards before but have never used on in the application you are proposing.

Mine is the V.W. GOLF/JETTA dated about 1981 or around.
I've had so-called "marine experts" look at the engine and, to be honest, they've caused more harm than good. One guy wanted to fit a crank driven fuel-lift pump to the engine as he was confusing engines like Beta Marine or Lister with a totally different engine.
My engine has a Bosch fuel-injection pump so it doesn't even need (or have a facility for) a crank-driven lift-pump. The trouble is, this guy then tried to remove the injection pump and must have altered the actual lift-timing which means I may have to buy a guage as well as an adaptor to check the actual lift. That will be close to 100 dollars, unless I just line the former timing marks back and hope for the best.
As for tools, V.W. isn't cheap. Specialists use guages, pullers and precise feeler gauges.
My new outboard will cost about 600 dollars second hand. Not as good as a diesel but very easy to service as the "marine experts" in this area do seem to be able to cope O.K. with outboards.


What VW diesel? IDI or TDI? There are plenty of VW diesels used in non-automotive applications like generators (they have great torque at 1500-1800 RPM, making them great for AC) and pumps.

They have been around for 30 years so their isn't too much that is secret on the IDIs. But the TDIs are a different story as their electronic injection controls are not well understood outside of the VW dealerships.

The injection systems are Bosch and they should be able to help. If you want to DIY, it won't require an engineering degree, just a few factory manuals and a modest collection of tools. Far less than purchase of a new outboard.

Mine is the V.W. GOLF/JETTA dated about 1981 or around.
I've had so-called "marine experts" look at the engine and, to be honest, they've caused more harm than good. One guy wanted to fit a crank driven fuel-lift pump to the engine as he was confusing engines like Beta Marine or Lister with a totally different engine.
My engine has a Bosch fuel-injection pump so it doesn't even need (or have a facility for) a crank-driven lift-pump. The trouble is, this guy then tried to remove the injection pump and must have altered the actual lift-timing which means I may have to buy a guage as well as an adaptor to check the actual lift. That will be close to 100 dollars, unless I just line the former timing marks back and hope for the best.
As for tools, V.W. isn't cheap. Specialists use guages, pullers and precise feeler gauges.
My new outboard will cost about 600 dollars second hand. Not as good as a diesel but very easy to service as the "marine experts" in this area do seem to be able to cope O.K. with outboards.Carrera - As you have probably worked o ut, the lift pump and the injection pump are two separate entities, with different purposes. The injection pump operates at high pressure and its timing / duration is critical to efficient / effective combustion.
The purpose of the lift pump is to ensure that the injection pump does not have to fight against an inlet vacuum in order to have sufficient fuel available at the injectors. It is a low pressure pump and, if of a positive displacement type, needs to have a relief mechanism between it's outlet and the injection pump's inlet. If it is not positive displacement, it is self-relieving (so to speak).
There should be no difference in the injection side of your engine due to it being marinised.
Marinising an engine only applies to the conversion of the cooling system to allow for external water to be utilised instead of radiator / air cooling. Any person who can work on an automotive diesel can also work on a similar marinised diesel. It sounds like the mechanics you are dealing with should also not work on diesel vehicles.

Mariner is a mercury design.I have rebuilt a couple of outboards before but have never used on in the application you are proposing.Correct, JH. Mariner is a division of Mercury. Often viewed as the budget cousin, they are very good engines. I've owned 4 of them over the years, and all have performed very well.

I'll explain what irritated me about this situation: The so-called "marine mechanics" in my area are used to dealing with outboards or brand name marine diesels such as Lister. These latter diesel engines are common in steel narrowboats. Most narrowboat owners don't tend to have a problem finding a mechanic should they have a problem.
My boat is different as it has a modified, marinized V.W. engine. Here there are some differences. For a start, my fuel injection pump is a Bosch and the only way you can remove it from the engine is to take off the timing-belt. There is no fuel-lift pump needed in conjunction with the Bosch pump.
On the other hand, narrowboats tend to have diesels that rely on the crank-driven fuel-lift-pump since these engines don't have a Bosch pump and I believe many of them can be removed without taking off the timing-belt.
So, that explains why the last mechanic I hired was trying to fit a fuel-lift-pump into the system and also trying to remove the injection pump without the tool.
In the end, he did a runner and left me with an injection pump that now needs re-timing e.t.c.
In this game, you live and learn. These guys don't seem to know much about VW engines so you can wind up creating more problems for yourself if you get the wrong mechanic working on the wrong engine.
At any rate, if you have a lift-pump pumping diesel into a Bosch pump, I suspect there will be major running problems. I contacted a VW branch a few days ago and the guy said such a system wasn't necessary and it will work fine as it is.
To be honest, large percentage of the marine experts wouldn't touch my engine with a 10 foot barge-pole as they're aware it's not a genuine marine engine.


Carrera - As you have probably worked o ut, the lift pump and the injection pump are two separate entities, with different purposes. The injection pump operates at high pressure and its timing / duration is critical to efficient / effective combustion.
The purpose of the lift pump is to ensure that the injection pump does not have to fight against an inlet vacuum in order to have sufficient fuel available at the injectors. It is a low pressure pump and, if of a positive displacement type, needs to have a relief mechanism between it's outlet and the injection pump's inlet. If it is not positive displacement, it is self-relieving (so to speak).
There should be no difference in the injection side of your engine due to it being marinised.
Marinising an engine only applies to the conversion of the cooling system to allow for external water to be utilised instead of radiator / air cooling. Any person who can work on an automotive diesel can also work on a similar marinised diesel. It sounds like the mechanics you are dealing with should also not work on diesel vehicles.

I'll explain what irritated me about this situation:...Carrera - Lift pumps don't do any harm, they just provide a (slight) positive pressure at the injection pump inlet, rather than the negative pressure created by head and friction if the injection pump has to raise its own fuel.
How big a job is it to pull the VW engine out? I guess carrying it could slow you down as you try to outrun that randy bull.
I don't know about the boggy canals of England, but down here in Oz, there are plenty of companies who just deal in repair of injection systems. As a large amount of their business is associated with repairs to truck engines, many of them offer mobile services.
Again, if these "mechanics" are balking over the difference between a marine diesel and a marinised diesel, you probably should steer clear of them anyway.
As a total digression, when I was working over in Papua New Guinea, I had a boat with a Yanmar 3-cyl diesel outboard. It was as heavy as all shite, under-propped, was a pig to start (rope-pull with a malfunctioning decompressor) and sheared the vertical drive shaft on the leg, instead of shearing the prop pin. It effectively ended any future desire for owning / using a diesel outboard.
Further digression - Today I'm working on restoring an old Zodiac ex-surf rescue boat that I have sitting out the back. The hypalon is cactus but, if I can get it to hold air, I'm putting on some Tuff coats to get it to last another year. I've got an old Tohatsu 25hp outboard for it which runs well.

Here, it's a crazy situation. I either sink or swim. Either I quit and sell the boat or I read as many books as I can and then do the job myself.
I've only just figured out how to get current to my heater plugs which is important as just turning the engine over isn't enough. Next I have to keep checking diesel fuel in getting to the injection pump and, if not, I'll have to fit either and electric pump or use a gravity feed.
I guess the only reason I have't quit is I find this hobby interesting and I don't want to give up so soon. Besides, an outboard will get me mobile while I keep working on the diesel engine.


Carrera - Lift pumps don't do any harm, they just provide a (slight) positive pressure at the injection pump inlet, rather than the negative pressure created by head and friction if the injection pump has to raise its own fuel.
How big a job is it to pull the VW engine out? I guess carrying it could slow you down as you try to outrun that randy bull.
I don't know about the boggy canals of England, but down here in Oz, there are plenty of companies who just deal in repair of injection systems. As a large amount of their business is associated with repairs to truck engines, many of them offer mobile services.
Again, if these "mechanics" are balking over the difference between a marine diesel and a marinised diesel, you probably should steer clear of them anyway.
As a total digression, when I was working over in Papua New Guinea, I had a boat with a Yanmar 3-cyl diesel outboard. It was as heavy as all shite, under-propped, was a pig to start (rope-pull with a malfunctioning decompressor) and sheared the vertical drive shaft on the leg, instead of shearing the prop pin. It effectively ended any future desire for owning / using a diesel outboard.
Further digression - Today I'm working on restoring an old Zodiac ex-surf rescue boat that I have sitting out the back. The hypalon is cactus but, if I can get it to hold air, I'm putting on some Tuff coats to get it to last another year. I've got an old Tohatsu 25hp outboard for it which runs well.

Hey, Carrera. Here's my next venture. I'm supposed to takeover this little carvel-planked gaffer when I go back to Australia in February. She's got a single-cylinder Yanmar inboard diesel that runs like a dream. I had her out for a trial run last time I was home - nice as pie.

Here, it's a crazy situation. I either sink or swim. Either I quit and sell the boat or I read as many books as I can and then do the job myself...So what's the current situation, Carrera? Have you still got the canal boat? Did you pull the People's Wagon engine down? Is it gonna be pressure pump, or gravity feed, or are you all iced over? Those canals must be slightly less attractive during the winter months.

After one year, I think I learned a fair bit about boats and think I'd been getting a lot of bad advice.
The thing to do in this situation (with an old boat) is to fit an outboard engine. This involves bolting a bracket to the stern of the boat with coachbolts. I'm using some plywood as a buffer and painted the ply with external marine varnish.
Seeing as the Mariner engine will go to the extreme left, I can leave my inboard diesel as it is. The plan will be to get it going but I already excluded marine mechanics as I fouind they don't understand VW engines.
The marine mechanics had me fitting an electric fuel-delivery pump when it simply wasn't necessary since Bosch fuel-injection-pumps themselves can drive fuel through the hoses.
However, I'm satrting with the outboard. Unlike my inboard, the outboard is easy to get at and not boxed in.

So what's the current situation, Carrera? Have you still got the canal boat? Did you pull the People's Wagon engine down? Is it gonna be pressure pump, or gravity feed, or are you all iced over? Those canals must be slightly less attractive during the winter months.

...The marine mechanics had me fitting an electric fuel-delivery pump when it simply wasn't necessary since Bosch fuel-injection-pumps themselves can drive fuel through the hoses...Carrera - I thought you were hibernating. Are you sure about not requiring a delvery pump? Are you sure that the vehicles that your model of VW engine is usually fitted to don't use fuel pumps to get the diesel up to the injection pumps? Having an injection pump lift against a head is not only pretty hard on the pump, it also means that, at the very slightest sign of a leak, the injection pump will suck air into the system.
I have a gravity feed on my Yanmar, which works nicely (and uses less than 1 litre per hour).

Hey, Carrera. Here's my next venture. I'm supposed to takeover this little carvel-planked gaffer when I go back to Australia in February. She's got a single-cylinder Yanmar inboard diesel that runs like a dream. I had her out for a trial run last time I was home - nice as pie.Very classy boat, Eoin.
Love the Gaff rig and from the freeboard she looks to be a dry and comfortable cruiser. What sort of timber is she built from...local?

Very classy boat, Eoin.
Love the Gaff rig and from the freeboard she looks to be a dry and comfortable cruiser. What sort of timber is she built from...local?G'day, SB. She's 3/4" carvel-planked jarrah, built by some Italian Bro's back in the early 70's. She was originally used for squidding. The Yanmar 12hp runs a treat, and pushes her easily at 6 knots in classic putt-putt mode.
I took her out for a quick test sail when I was down in Oz in December. I pick her up when I get back down in mid-Feb. She comes complete with a mooring on the raging Swan.
I'm looking forward to when SWMBO puts me in the dogbox, coz the new dogbox is a mighty fine place to be. Watch out, Rotto.

I'm positive. I cracked the fuel delivery system today. It wasn't rocket science. I unscrewed the fuel-injector unions and worked the primer bulb I fitted into the hoses. That drew diesel up through the filter and some way into the inlet hose. I then energised my Bosch injection pump and connected up the starter-motor lead. Then, for the first time, I could see diesel squirting out of the union pipes every few seconds.
So, I have fuel delivery. No doubt. Bosch rotary injection pumps have internal pumps so there is no need for a crankshaft driven diaphragm pump to be fitted.
Now I have to test the heater plugs as there isn't enough heat in the cylinders.
I've been wasting my time with local marine mechanics as they don't know this or how the wiring is set up to the Bosch pump.
You'll find most marine diesel engines are different than mine. Most have an actual crankshaft-driven fuel pump that actually delivers the fuel to the pump and keeps it pushing through the system - like a heart. Many marine injection pumps even fit onto the engine via splines, although mine is driven by the cambelt.
I should point out my boat is a real challenge. It's very old and came to me as a virtual heap of scrap. Restoring it is a huge project, involving big cycle rides to get there and back. I have a hell of a lot of work to do on it.
I'm adding an outboard as an extra engine.
I had a nightmare once it sank on its maiden voyage. Woke up with a jolt.


Carrera - I thought you were hibernating. Are you sure about not requiring a delvery pump? Are you sure that the vehicles that your model of VW engine is usually fitted to don't use fuel pumps to get the diesel up to the injection pumps? Having an injection pump lift against a head is not only pretty hard on the pump, it also means that, at the very slightest sign of a leak, the injection pump will suck air into the system.
I have a gravity feed on my Yanmar, which works nicely (and uses less than 1 litre per hour).