'79 Johnson v4 Outboard. Best or possible to add an anode?

redmopar

Seaman
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Nov 30, 2004
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58
'79 Johnson v4 Outboard. Best way or possible to add an anode? There is none on it. My motor is getting eaten. It is never in the salt more than 3 days, but it is slowly getting eaten dispite flushing it within hours of pulling it out of the water. Need help! :confused:
 

R.Johnson

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Sep 24, 2003
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Re: '79 Johnson v4 Outboard. Best or possible to add an anode?

What is your boat made of, Fiberglass, aluminum ? Are you using a battery charger while it is docked? If the boat is aluminum, is it being used as a ground?
 

redmopar

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Nov 30, 2004
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Re: '79 Johnson v4 Outboard. Best or possible to add an anode?

Boat is fiberglass. Only charged while on the trailer.
 

redmopar

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Re: '79 Johnson v4 Outboard. Best or possible to add an anode?

On a side note, but a possibly related story. Last time I had it out we had a sudden unseen squall hit in the middle of the night while we were camping in the SE Florida flats. This boat is a bassboat and the waves were exceeding 4' in the middle of the night. We were on a beach facing west with the winds coming out of the west so the waves were breaking hard. I decided since I had no automatic bilge and the anchor was dragging from the 20 knot winds and waves, I should spend the night in the boat. Several hours went by and it had drifted back twards the shore. I dropped the motor in and cranked it. As I touched the controls on the control module, I was hit with a big static charge. Of course the control module is grounded to the motor. I then ran it forward and ran to the bow to pull in the anchor. As I pulled it in i was getting a tingling static discharge on the rope. As soon as I went to grab the anchor chain, visible arcs flew from my fingers. I then went back to the controls for a third discharge. First time this has ever happened to me.<br /><br />Also just to throw more info out there, most of the corrosion is occouring in the exhaust housing and it has a stainless prop.
 

Dunaruna

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May 2, 2003
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Re: '79 Johnson v4 Outboard. Best or possible to add an anode?

VISIBLE ARCS FROM YOUR FINGERS! <br /><br />Nothing to worry about, its normal........ for the Green Lantern!!! :D <br /><br />How can the anchor chain be conducting on a fibreglass boat? I'm no meteorologist but it may be related to the storm. Maybe a leakage from a nearby boat or marina? Probably an earth problem with your boat.<br /><br />As for not having a sacraficial anode, not technically correct - your motor leg is the anode but you need to avoid the sacraficial part. Electrolysis will eat at the least noble metal it can find - your leg. You need zinc. Plenty of clip on, bolt on & 'hang over the side' anodes on the market and probably some that are designed specifically for you motor but anything is better than nothing.<br /><br />Aldo
 

G DANE

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Nov 24, 2001
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Re: '79 Johnson v4 Outboard. Best or possible to add an anode?

Heavy corrosion problems is usually seen if someone reinforces transom using a large stainless steel plate. The stainless will transfer its corrosion to the aluminium alloy. Best would be: Replace the stainless with aluminium plate, or mount an anode on the stainless plate or in good electrical contact with stainless, a place that is submerged when boat is in water.
 

umblecumbuz

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Sep 25, 2004
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Re: '79 Johnson v4 Outboard. Best or possible to add an anode?

Just a few comments ...<br /><br />Electrolytic action can be a small pain or a big problem!<br /><br />Water is an electrolyte, so whenever two dissimilar metals are immersed in it while in contact with each other, current will flow – that is, a battery wil be created - and the less noble metal of the two will get eaten.<br /><br />Thankfully, this effect can be turned to advantage by introducing an ‘ignoble’ metal that has greater voltage potential than the others – ie. an anode made of sacrificial metal, such as zinc or other suitable alloy. <br /><br />But there is one thing that must be remembered for this system to work – all the various metal parts that come in contact with water must be connected together and also connected to the sacrificial anode. Any single item left out of this loop will itself get separately eaten. Obviously this is more of a problem with fibreglass boats. As an example, if you have trim tabs on a fibre boat, either fit an anode to each one or wire them to the other metal components. Even trim tabs with a hydraulic actuator that has nylon ball-joints connecting the actuator to the tab will see the hydraulic unit attacked, because it is out of circuit.<br /><br />One thing that works against these precautions is the poor wiring record of many dock areas. Stray current can often overcome the miniscule current created by your boat, and if you’re hooked up to shore power , you’re effectively using your little anode to protect all the other boats and paraphenalia in the dock! Unplugging is a partial answer to this one.<br /><br />Bottom line? Zinc only protects what it is connected to! So fit separate zincs to each separate metal component for maximum protection.
 

redmopar

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Re: '79 Johnson v4 Outboard. Best or possible to add an anode?

Thanks for all the info. No plates, tabs(yet), or any other from the aftermarket hanging out in the water and stops in the marina are rare and short when they happen. When they do, I never have before connected power. Well, back to my original question, is there a better way/place to mount an anode. I scoured the aftermarket for one specifically for my outboard and came up dry. Dosen't mean there is not something out there designed for me(like a anode that replaces the steering trim tab.) My owners manual mentions a "kit" being available, but my dealer has never heard of it. If no one knows of anything I may attempt to make a bracket(aluminum) that puts the anode just below the stern bracket itself by utilizing the transom bolts. Sound like the plan?<br /><br />Earlier Dunaruna said:<br />"How can the anchor chain be conducting on a fibreglass boat? I'm no meteorologist but it may be related to the storm. Maybe a leakage from a nearby boat or marina? Probably an earth problem with your boat."<br /><br />This all happened in the backcountry and it appears that I was being used as a static charge "battery." For some reason the motor built up a charge different from the anchor with the hull insulating the two. The motor was tilted up almost out of the water in case the boat acedentally beached itself. I touched the controls on the motor and charged myself one way, and grabbed the anchor and I charged another way or just discharged me into the water. Where the charge came from is not clear. If it were from bad marina wiring and was enough to throw arcs off my fingers, I suspect I may have been injured from this. It was, however, a lightning storm but with few strikes within earshot. Probably static related. At the very least, it was strange. A good story to tell over beers this weekend.
 

umblecumbuz

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Sep 25, 2004
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1,062
Re: '79 Johnson v4 Outboard. Best or possible to add an anode?

Drill a couple of holes in your anti-cavitation plate and screw the anode there - on top of the plate, not underneath. The bare metal in the holes will be a good thing, so don't touch them up with paint.
 

seahorse5

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Jan 24, 2002
Messages
4,698
Re: '79 Johnson v4 Outboard. Best or possible to add an anode?

The factory makes a "zinc" anode that bolts to the top forward area of your "cavitation" plate. It is horseshoe shaped and you drill 2 holes in the plate to fasten it. See a knowledgable dealer.
 

redmopar

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Nov 30, 2004
Messages
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Re: '79 Johnson v4 Outboard. Best or possible to add an anode?

Thanks seahorse, alot of help there. But I get the definite impression my dealer could care less about my old motor and just assume I get a new suzuki or omc. When I asked him, he said if it did not come with an anode there is not much I can do. New motor is not in the budget for many years and I have a certain amount of sentimental value in the setup as well as pride in the fact that this ol motor has been proving more reliable than my friend's newer engines. The short of it is I would love for this sucker to last as long as possible.<br /><br /><br />Think I found them by process of elimination anyways. Seems to be the only "horseshoes" for OMC outboards out there. OMC part number 392123 or 392462. Any idea what type of fastners to use? Maybe a set of galvanized non-hardened(in case I need to break em later) machine bolts with lock nuts? I have the original parts list for my OMC and i'll try searching it by p/n tonight since they were not obvious to find by description. If anyone has the info handy I would appreciate it. If I can't figure it out, i'll be ordering the one that looks best and crossing my fingers. :( <br /><br />Oh yeah, stillfishing. Great idea also. Would be my plan to put some generic blocks on there if seahorse hadn't come through with the horseshoe. Thanks.<br /><br />
89419F-f.jpg
<br /><br />392123<br /><br />
89420F-f.jpg
<br /><br />392462
 
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