outboard for a Mac Classic D/S

[timebandit]

I often thought an opposing set of car door lock solenoids to do the shifting and a set of buttons on the tiller.

The forward button for forward, the middle button for neutral and of course the aft button for reverse.

Just a simple automobile throttle control cable with a twist to hold for the throttle.

Once upon a time long long ago there was a tiller to engine steering control
by Tom Stockwell, I think.

It seems that all the free sites have been eliminated and doing searches for his engine steering seems to be deleted.

This system may be on another Mac or trailer site but I couldn't find, you may want to track this down.

It was simple and cheap to build an easy to connect and disconnect.

 

[walt]

Very recent thread on fuel problems with the Tohatsu
http://www.sailnet.com/forums/gear-maintenance/60033-tohastsu-8hp-4cycle-tech-questions.html

Im assuming these gas issues apply to pretty much any outboard you can buy now...

Over the last year, Ive tried to find a fuel/water seperator filter but the only ones I can find (I believe Racor) look to be made for much larger engines - and would be a fairly bulky install on the Mac. My gas tank is not inside the Laz so would like to also install the filter maybe somewhere in the well area?

I may just put a smaller conventional filter in the gas line but is there a nice water seperator option better suited for an outboard using considerably less than 1 gallon per hour?

 

[Sumner]

Walt did you see this picture timebandit posted? To me it looks like the Nissan/Tohatsu dosen't have a lof of motor protruding into the motor well, but can't see the tiller elbow. This one looks kind of massive by and below the mount. I wonder if it is the power tilt model.

On the gas issue. I for one wouldn't use a gas with ethanol in it unless it is a last resort. Too many negatives, less power, absorbs water and the corrosion thing. It is good for a racer, but not so good for us. A lot of people think that alcohol will produce more power. If you have equal amounts of gasoline and alcohol the gasoline wins. In a race motor you put in much more alcohol volume wise than gas. You need much larger jets and such to supply the volume needed. The big advantage over gas is it burns really cool in a race motor, so the chances of detonation go way down. We ran alcohol the fist year we were on the salt with Hooley's Stude, but then changed to a blown gas class where we got our record. Blown gas over 5 miles wide open is like a time bomb. So far we haven't blown the motor, but we run air/fuel ratios in the 9.6 to 10.6 range which is way rich. The extra gas helps to cool in our situation.

With a car motor or boat motor it doesn't know if you are running a straight gas or ethanol blend and as far as I know only puts in the same volume of fuel, so is going to make less HP. Did you see the guys mileage figures when he ran the blend in his vehicle. If the blend is cheaper then it might be a wash price wise.

Don't forget the humidity thing also where that guy is having problems to where you are. I would wait on a water separator until I saw if it was a problem. Now since we want to go down to where he is we might put it on our wish list .

c ya,

Sum

Our Trips to Lake Powell, UT - Kootenay Lake, Canada - Priest Lake, ID

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[walt]

I think the outboard in the picture (thanks timebandit) could also be the remote control model. If its got a tiller, it would not rotate.

I made a simple fixture to simulate the Tohatsu and it looks like the outboard must be moved back by a minimum of 3 inches in order to rotate and this is also only if the outboard is offset (towards center) a little in relation to the transom openening. The attached pictures show the fixture and the dimension are taken off the drawing but the key item is the rotation axis of the outboard and how far out the "items" which would interfier with the transom well are from the rotation axis. The elbow on the tiller is about 10.6 inches from the rotation axis. The interfierence on the starboard side is a little less at about 9.2 inches from the axis. So the outboard can be offset in the well (moved a little to center).

At this point, Im assuming that I would need to move the Tohatsu back about 3.5 inches and moved slightly to center in order for it to rotate. If the outboard was raised about an inch, you might get away with three or less movement back. Seems the main hassle about moving the outboard back 3-4 inches is that the shifter also gets moved back and then becomes a little hard to get at. You could of course make some sort of linkage on the shifter but simple is better.

 

[walt]

After looking at a the Honda, Nissan/Tohatsu, Yamaha, Suzuki, I think Im going to do the same as Sumner was thinking and go with the Nissan/Tohatsu 9.8 hp 25 inch shaft electric start.

I played with the fixture I made more and if you look at the 26C transom, it opens up as you go higher. In one of the attached pictures, there is a 2.5 inch block on the fixture which raises the effective transom height by 2.5 inches under the fixture (similutes the outboard being raised by 2.5 inches above the existing transom). Using the fixture to simulate the places on the outboard which would interfere with rotation, it looks like the outboard would need to be set back by a minimum of 2.5 inches.

The drawing shows what Im thinking. My Honda clamp willl handle a maximum transom width of about 2.4 inches. So Im thinking the new transom would be two 3/4 inch wood sections plus two 1/4 inch thick AL plates for a total thickness of 2 inches. All four peices would be epoxied together. The wood could be a good grade of plywood as Sumner suggested with a good epoxy coating.

Then, the new transom would need to be moved about exactly one inch back from the exisiting aft side of the transom.

Raising the outboard by 2.5 inches would compensate a little for it being moved back by 2.8 inches. The 25 inch Xlong shaft would still put the prop 2.5 inches lower than my current long shaft.

Sumner, your idea in post #19 looks like a good way for me to get the 1 inch extension backwards.

 

[Sumner]

...............
Sumner, your idea in post #19 looks like a good way for me to get the 1 inch extension backwards.

Instead of having those bolts sticking out I'm going to just tap 4 holes there and then the removable mount will bolt on and just use a bolt of the right length for the thickness of the mount you want.

You know with the extra 5 inches of shaft length with the 25 inch model you could even raise it higher than what you are saying. That would move the controls up even closer and remote controls might not be needed, especially if a tiller handle..................

............was added to the top of the motor. I've never had problems so far having the prop come out of the water on the lakes we have been on and a couple times the conditions were less than good. Now I will like the option dropping it onto the transom for the full 25 inch depth when we go to Florida.

Also before going the 'glassed' route on the mount I would just paint the individual pieces of plywood on both sides and do the end grain well and use it. Then if you like it make another one. Chances are you will have plywood left over. Also on the metal, both sides is fine, but I'll probably only have it on the inside where the screws are. On the other side the pressure is spread over a large area by the way the outboard mounts are made. On the aluminum .120 or .090 aluminum 5052 or 3003 or any of the 6000's would work fine.

I'm going to make the mounts that will stay on the boat on either side of the motor 1 1/2 inches thick and have some of that, so you don't need to find it for me any more. Thanks for the offer to find some. If you have already I'll be happy to still pay for it as I like having aluminum around. I think they can be easily up to 2 inches thick and not interfere with the motor if they are left on all the time. Now we will have the option of having the motor down at 25 inches without the mount to higher with it.

I'll still be happy to machine two mounts for you.

c ya,

Sum

Our Trips to Lake Powell, UT - Kootenay Lake, Canada - Priest Lake, ID

Our Mac Pages

Mac Links

 

[walt]

Another thing Im wondering about..

It looks like the Mercury 9.9 has a gas primer "pump" on the engine (little rubber "push in" at the front) but the Nissan does not. Just going off my experience with my lawn mower, I like the idea of having the gas primer pump for starting the engine. I wonder how much difference this makes??? The entire tiller assembly is also different for the Mercury - no drawings seem to be available on the internet to see how things would fit.

Also interesting.. I was looking at the electrical diagram for the Nissan and there is an internal 20 amp fuse - but it is NOT in the circuit for the electric starter motor. According to the diagram, there is NO fuse between the starter motor and the battery. Dont know what the starter motor draws but I think its safe to assume it would very easilly blow a 20 amp fuse. I have an 80 amp fuse about a foot from my battery in case of a wire short (now composed of 2 six volt golf cart batteries under the V berth). Im guessing that I wont have any issue with the 80 amp fuse.. Does anyone have any experience with external fusing and starter motors? At worst, Ill just have to go to a higher amp fuse - which Id prefer not to do.

 

[walt]

Proto build.. The block is 12 inches long, about 8.75 wide, made from three pieces of 12 mm ply (all epoxied together) and 1/8 inch Al skins. Total weight added to transom not including the bolts is 3 pounds. I think a hair wider might be better since I want to bolt the outboard to the block - but then it would also be heavier.

It puts the outboard back by 2 5/8 inch and up by 2.5 inch. The transom area under bracket is not at all flat. I think years of the outboard hanging back there have distorted the glass a little based on the same area under the ladder being a fair amount flatter.

 

[walt]

Still haven't got the outboard yet (back ordered and now the boat shop closed until into the new year).. but I did the wiring for the electric start. I have a single battery (two 6 volt golf cart) as far forward as they can possibly go under the V berth and have a length of 4 gauge wire going to the main electrical distribution area under the sink. I just put in an additional length of 4 gauge wire back to the Laz area.

I also put in a little break out box in the Laz area (pictures and shown in the wiring diagram). The outboard has the wires permanently attached so Ill feed them through the fiber glass in the outboard well to the Laz area with a ss vent to keep the water out of the hole. The two power wires will bolt onto the + and - 12 volt studs in the breakout box. I may shorten the wires which come with the outboard - but I probably wont need to.

I have an 80 amp fuse very near the batteries in case there is a short on the main 12 volt line. Hopefully it doesn't blow for the starter motor currents.

 

[Sumner]

Walt that looks good. The wiring diagram shows..............

http://www.nissanmarine.com/tech_talk/pdf_files/Nis_NSF8A3_98A3.pdf

........ a 20 amp fuse for the starter leads from the battery to the outboard. I know you have some run from up front, but do you really think the 4 gauge is needed. I have 8 gauge now from my generator/solar panel going from the lazarette to the batteries in the cabin. I'm thinking that is plenty large enough for the run and will use it for the outboard starter also. What do you think?

I'm also going to add an 80 watt panel to the system for the new frig.

c ya and Happy Holidays,

Sum

Our Trips to Lake Powell, UT - Kootenay Lake, Canada - Priest Lake, ID

Our Mac Pages

Mac Links

 

[walt]

The outboard 20 amp internal fuse is in the circuit which runs the solenoid and the alternator charging. The starter motor gets connected directly to the 12 volt when the solenoid closes - no fuse in this line. The 80 amp fuse near my battery is more to keep the wire from burning up if I short the 12 volt - but its also the only fusing on the starter motor when the solenoid is closed.

Part of the reason I have 4 gauge is that I have a bunch of it.. but my batteries are also as far forward under the Vberth as I could get them (supposed to help sailing boat speed). Ive been looking at the Mercury outboards and I think the electric start models come with about an 8 foot length of "about 8 gauge - not sure. So I'm adding an additional probably close to 26 foot length (not to mention its round trip) to this and also using deep cycle rather than a starting battery. I think both of these add up to a little higher impedance - so I like the 4 gauge.

Bob Hissey who used to own a Mac but now owns a Hunter 26 (or 260?) had about the same config as I have with deep cycle batteries all the way forward and the 4 gauge wires to the back and said it worked fine with his 9.9 Honda electric start. That is the only "data point" I know of. I would guess you probably will have no problem but don't know as this will be the first electric start outboard Ive owned.

 

[timebandit]

This may help lessen your fears about power drain for starting a itty bitty motor.

From another forum

Maine Sail

Senior Member
Join Date: Jan 2003
Location: Maine Coast
Posts: 2,315
Rep Power: 9

Engine Start Video / Real World Data
Hi All,

I saw a need for something often debated but rarely ever clarified.

Many sailors/boaters often believe that you need to switch back and forth between your house bank and your start bank or as I prefer to call it, "emergency bank" of batteries for engine starting.

The truth is you don't! Switching back and forth from bank 1 to bank 2 only leads to eventual human error, as has been reported here all to often, and you will, in due time, fry your alternator diodes with a mental lapse or via a crew member asked to switch banks.

The reality is that your system should be wired to prevent this but that is another subject for another day and most will never get this far down the project list.

I am simply trying to prevent any more fried diodes with this video!

Another mis-truth that is often perpetrated amongst sailors is the absolute need for a "starting" type battery to start your small diesel engine.

This video will show why it is not necessary to use a thin plate high CCA rated battery to start a small auxiliary diesel engine. The max load when starting my engine, a four cylinder 44hp, is 132.5 amps for less than two seconds. Any deep cycle marine battery you can find will have a LOT more than a 130+/- CCA, CA or MCA rating.

Start batteries don't, and won't, generally last as long as a true deep cycle battery so pound for pound deep cycles generally cost less in the long run.

You no longer need to be affraid to use deep cycle batteries for your starting/emercency bank or to start your engine using your house bank. I've always started my engine on my house bank

. Hopefully this video will give many of you piece of mind around the subject of starting and how little it actually consumes.

What Happens When My Engine Starts Video (LINK)

Or click the photo:


Stats:

Engine - 2003 Westerbeke 44B, 44hp four cylinder diesel (marinized Mitsubishi).

House Bank - 2 Group 31 batteries 120 ah rated each / 240ah bank

Glow Plugs - They consumed between 30 and 56 amps for about 8-10 seconds.

Starter - Max draw of 132.5 amps for about two seconds.

Battery Monitor - Xantrex XBM
__________________
______
-Maine Sail

Still haven't got the outboard yet (back ordered and now the boat shop closed until into the new year).. but I did the wiring for the electric start. I have a single battery (two 6 volt golf cart) as far forward as they can possibly go under the V berth and have a length of 4 gauge wire going to the main electrical distribution area under the sink. I just put in an additional length of 4 gauge wire back to the Laz area.

I also put in a little break out box in the Laz area (pictures and shown in the wiring diagram). The outboard has the wires permanently attached so Ill feed them through the fiber glass in the outboard well to the Laz area with a ss vent to keep the water out of the hole. The two power wires will bolt onto the + and - 12 volt studs in the breakout box. I may shorten the wires which come with the outboard - but I probably wont need to.

I have an 80 amp fuse very near the batteries in case there is a short on the main 12 volt line. Hopefully it doesn't blow for the starter motor currents.

 

[walt]

Thanks Timebandit. My "fear" is about blowing the 80 amp fuse I have near my battery bank. I'm pretty much not at all worried about the batteries or the wiring easily handling everything. Maine sail recorded 132 amps for several seconds which would likely blow my fuse.. but he is starting a four cylinder 44 hp motor and I'm starting a 9.8 hp two cylinder.

I picked the 80 amp because of price - its the highest amp fuse for the "package".. but given that its main purpose is to protect the 4 gauge wires from burning up from a short somewhere in the distribution (which goes the entire length of the boat now), I can go to a much higher amp fuse. Id just prefer not to since would have to purchase and install the fuse all over again.

I also set up this system thinking I might run a short duration high amp inverter - for either a microwave or blender. Both of these would also put a pretty big strain on the 80 amp fuse so maybe Ill end up going to higher amp fuse regardless.

 

[Sumner]

Timebandit thanks for the video. It looked like the high amp draw was maybe even shorter than what he said.

Walt I installed a breaker. Is there a reason not to consider that over the fuse. Also if you were still having problems and I don't think we will you could put in a switch to by-pass the fuse while starting, but that would be a real pain in the a##.

Another option might be a 'slow' blow fuse if that isn't what you have. I wonder if my breaker is faster or slower than a normal fuse.

Personally I don't think you are going to have a problem. When do you get the outboard?

Sum

Our Trips to Lake Powell, UT - Kootenay Lake, Canada - Priest Lake, ID

Our Mac Pages

Mac Links

 

[walt]

If you have ever seen what happens to a screw driver when shorting a big battery (my story shall remain untold...), well... no way in heck am I going to bypass the fuse for starting the motor - too much stuff can be happening while sailing and I'm sure I would forget that I had bypassed the fuse.

Looks like 4 gauge wire could be fused as high as 125 to 150 amps. I dont have any good reason for the fuse vs. the breaker.. Breakers tend to be somewhat "slow blow" so maybe a little better?? The fuse issue might be the first good reason to go with 4 gauge vs 8. I don't know what is the largest fuse you can use with 8 gauge but if the largest safe to use fuse blows when starting the outboard, this would be a problem.

Ill probably get the outboard Tuesday or Wed next week (hopefully) and will probably fire it up the first day the temp gets close to 50F.

Edit - watching the video, it also looks like the current Maine sail measured was BOTH the glow plugs and the starter - and we dont have glow plugs (looked to be around 30 to 35 amps during the start). Anyhow, Ill video tape about the same thing.

 

[walt]

Got the outboard in, looks like moving the outboard back 2.25 inch and up 2.5 inch works fine for allowing the new 9.8 four stroke to fully rotate

 

[walt]

more picts. This is extra long shaft electric start.

Ill get it fired up in a few days and measure the starter current.

 

[Robspan]

That looks great, Walt. A very clever solution. When will the ice melt so you can try it out for real?

 

[Sumner]

Walt the outboard looks nice. I think the extra-long shaft is the way to go. We will order ours in a month or so.

I'm still interested in the amp draw during starting, so hope you get to do that when you find the time.

c ya,

Sum

Our Trips to Lake Powell, UT - Kootenay Lake, Canada - Priest Lake, ID

Our Mac Pages

Mac Links

 

[walt]

As soon as the ice melts, the boat will be in the water.. I'm guessing mid March this year as its been colder than the last few winters.

Sumner, I plan to measure the starter current very soon - within a couple days. I wont be able to tell the exact gauge of the wire which came with the outboard as the length it came with is about perfect for where I put the breakout box - so I don't need to cut down the length.

FYI, I did not special order the prop shown in the pictures - it came with the outboard. I don't know the pitch, maybe it is stamped on the prop somewhere but it looks good for the sailboat application. Maybe its the one they supply with XL shaft since its probably mostly sailboats using the XL shaft??