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Author Topic:   Electric Start Motor Direction of Rotation

Binkster posted 08-18-2013 02:32 PM ET (US)
Explain this one to me; I offer no excuses: I have owned electric-starting outboards from the 60's. I have a 1959 14' Sea Fury powered by a 1961 Evinrude Starflite 75hp V-4. I run the boat usually every month at the AOMCI meets. The engine runs flawless, but last month the tach wouldn't work. I couldn't find any broken wires. The ground for the tac runs to the common ground and the positive lead attaches to the positive post on the battery. I normally disconnect the ground cable when the boat is not in use. So this morning I decide to start her up on the hose and run the carbs dry as I usually do. I discover I have the cables hooked up backwards. Red tape wrapped around the positive cable was hooked to the ground post and ground hooked to hot post. Also tac positive wire hooked to ground post. I ran the boat like this at the last two meets. No wonder the tac wouldn't work, but why did the engine start and run as usual with no apparent damage. I straightened out all the wires, engine runs good and tac works fine. I can understand that but I always thought hooking cable up backwards would do damage.
I have never done this before, am I losing it??
rich
Binkster posted 08-18-2013 03:21 PM ET (US)
This engine doesn't have a magneto ignition that was common to outboards of that era, it has what they call a Unicharger ignition, same as on autos of the 60's.
rich
contender posted 08-18-2013 04:17 PM ET (US)
Bink: I know it sounds crazy but since the cables were hook up backwards, how come the battery did not spark right away when you hooked the cables back to the post?. I have also heard hooking up the cables backwards would blow the diodes in the tach. I guess you have been blessed, but like you said how in the hell did it fire up? Are you sure the wires are right on the starter? still does not make any sense...
Binkster posted 08-19-2013 09:20 AM ET (US)
No. the cables did not spark when they were hooked up backwards. The antique boat does not have a dedicated battery. The battery I use in the antique boat, is the battery, which is fairly new, out of my 13 ft. Whaler. I only run that boat at the antique boat meets, and since I have not been using my Whaler this summer, When I put the battery in the antique boat in July, I just left it there. I ran the boat with the battery hooked up backwards for about an hour in July, and about an hour last saturday. thing is, the battery is even fully charged.
rich
conch posted 08-19-2013 11:22 AM ET (US)
I think that motor could be started in the opposite direction of its normal rotation and run. Mercury back then shifted between forward and reverse that way ,and OMC first offered counter rotation running one engine in opposite crankshaft direction.
I would think though that you would notice as soon as you put the motor in gear.
Parts that may have been ruined may be in your junction box where your solenoid is. Do you have the optional under flywheel alternator? More things to cook in the junction box then.
jimh posted 08-20-2013 03:29 PM ET (US)

quote:
...why did the engine start and run as usual with no apparent damage...[?]
The DC electric motor that is typically used as a starter motor for internal combustion engines is a special type of DC motor, called a series-wound DC motor. The direction of rotation is not determined by the polarity of the DC current flow but rather by the relationship of the phase of the field and stator windings, with the result that such a motor rotates in the same direction even if the polarity of the battery connected to it is reversed.
The best explanation--in reasonable terms--of how the DC starter motor works is given in
http://zone.ni.com/devzone/cda/ph/p/id/53
where it is noted:

quote:
The direction of rotation of a series motor can be changed by changing the polarity of either the armature or field winding. It is important to remember that if you simply changed the polarity of the applied voltage, you would be changing the polarity of both field and armature windings and the motor's rotation would remain the same.

In connecting a battery with the polarity reversed, the DC starter motor would have run in the normal direction. The engine would have been cranked over in the normal direction. The engine probably started and ran on its own magneto power.
conch posted 08-20-2013 05:31 PM ET (US)
I was thinking permanent magnet field coils. Then the coil, condenser, and solenoid etc. also functioned with reversed polarity. Maybe the alternator too if he has one.
Rich said he had the coil model not the magneto.
Chuck
seahorse posted 08-20-2013 06:04 PM ET (US)
The distributor ignition uses an alternator and a series of diodes plus a fuse. The fuse usually blows on reverse polarity and sometimes the diodes are damaged and other times they are OK.
The fuse is a small square up on the flywheel guard if I remember correctly after all these years. It consists of 2 small ceramic squares and a link that goes from one to the other.
conch posted 08-20-2013 06:18 PM ET (US)
The starter would not work in reverse anyway as the bendix wouldn't engage the flywheel. But it would spin real good.
Chuck
jimh posted 08-21-2013 08:49 AM ET (US)
The connection of the battery to the engine electrical wiring other than the starter motor is usually through a fuse. The fuse would probably blow with a reversed polarity connection. This would leave the battery disconnected from the engine, and only connected to the starter motor when the solenoid was operated. Once the starter motor cranked the engine, the self-powered ignition system would generate spark without the battery being connected, just as it would if you pull-started the motor without a battery.
jimh posted 08-21-2013 08:51 AM ET (US)
By the way, the solenoid coil is happy to operate with the polarity reversed. See
http://www.solenoid-valve-info.com/solenoid-valve-coil-polarity.html
conch posted 08-21-2013 09:20 AM ET (US)
Jim what is the self powered ignition system in this case as there is no magneto?
Chuck
jimh posted 08-21-2013 09:46 AM ET (US)
Most older outboard engines run without a battery. They typically have permanent magnet alternators that generate electricity by rotating permanent magnets around a fixed coil. Whether or not the motor in this discussion has such a device is unknown to me, but, on the basis that it ran with the battery polarity in reverse, I would tend to think it is capable of generating its own electricity for operating the engine and generating spark. This is quite common in older outboards. They can be pull started and run without a battery.
I think you can now have a sidebar discussion on whether or not the word magneto covers permanent magnet alternators in your understanding of electrical terms. Compare your definition with http://www.merriam-webster.com/dictionary/magneto
Binkster posted 08-21-2013 12:04 PM ET (US)
Thinking of hooking up an amp. guage to see if the motor is charging the battery. I'm pretty sure it is as I have run it twice in this condition in the past 2 months, about an hour each time without charging the battery, with no problems.
rich
conch posted 08-21-2013 12:18 PM ET (US)
Jim it sounds very much like the modern E-Tec, can be pull started and run without a battery and has a magneto (alternator).
Chuck
jimh posted 08-21-2013 12:56 PM ET (US)
If a fuse blew fast enough, you may have avoided any permanent damage from the polarity reversal at the battery.
Binkster posted 08-21-2013 03:24 PM ET (US)
So, I should check the junction box and look for the fuse to see if it is blown. I read somewhere that it isn't a normal looking fuse. My manual has no info I can find on the junction box. It is a metal box about 4"x8" by 3" thick, mounted usually in the boat with a solenoid inside and battery cables running in and out and all other wiring also. I haven't looked inside in about 3 years, since I set it up, but I don't remember anything that looked like a fuse. This juction box was eliminated a few years later, and everything was mounted under the cowling, as in modern outboards.
rich
Binkster posted 08-21-2013 04:50 PM ET (US)
Here is a diagram of the juction box for a 1961 Evinrude 75hp V4. Do you see a fuse??

rich
silentpardner posted 08-21-2013 05:06 PM ET (US)
[Essay on how fuses operate deleted because it seemed to end with a self-contradiction. I have deleted this because there is no value in collecting misinformation. For a good reference on how fuses operate, see http://en.wikipedia.org/wiki/Fuse_(electrical)--jimh]
jimh posted 08-21-2013 06:13 PM ET (US)
Whether or not the battery charging circuit of an outboard engine can tolerate the connection of a battery to it with the polarity of the battery reversed depends entirely on the circuitry of the battery charging circuit. Some circuits will not tolerate a reversed-polarity battery, will draw very high current, and that high current will either blow a fuse, if there is one, and there usually is, or damage some circuit element due to the high current flow. Other circuits care not a bit about a battery reversal, and nothing bad will happen, no current will flow at all, and the battery will be, in essence, completely disconnected from the circuit by a reverse-biased diode. The exact circuitry of the engine under discussion is unknown to me. If we can have a component level schematic diagram, we could look into how the circuit may have behaved in this situation. Without the circuit diagram, we can only speculate on how the circuit behaved when the polarity of the battery was reversed. What seems to be evident is the engine has not sustained damage, or at least is appears to not have sustained damage.
There is no mystery to why the starter motor direction of rotation was not affected by the battery reversal, and no mystery about why the solenoid operated normally with a polarity reversal. (See the links to explanations of these behaviors. What is evident is that many readers may not have been aware that the starter motor and solenoid would have been tolerant of the polarity reversal and would have operated normally.
If there is no fuse, or if there is a fuse and it has not blown, then it appears that the engine has tolerated a battery polarity reversal with no damage, and, in fact, can run with the battery reversed in polarity. However, I don't think the circuitry of the spark generation devices works with a reversed polarity, but, if the battery was effectively disconnected by the action of diodes in the circuitry, then the engine just ran as it would have when no battery was connected at all. This is not a surprising outcome, as many outboard engines will run without a battery, and in older outboard engines this characteristic is fairly common.
seahorse posted 08-21-2013 06:36 PM ET (US)

My previous post mentioned the fuse being on the flywheel ring guard, but that was only for the newer models. The 1961 alternator equipped 75's had the diodes and fuse in the boat mounted junction box. Here are links to the parts book.

http://www.marineengine.com/parts/vintage-evinrude-johnson/FORM_2104/ catalog.html?http://www.marineengine.com/parts/
http://www.marineengine.com/parts/vintage-evinrude-johnson/FORM_2104/ catalog.html?http://www.marineengine.com/parts/
seahorse posted 08-21-2013 06:42 PM ET (US)
I guess Marineengine.com does not allow direct links to their parts pages. Just click on Evinrude, then the year, then your model no. or the Johnson V4A-13 model.
The fuse is item #81 part number 379788 on the alternator junction box page.
conch posted 08-21-2013 06:45 PM ET (US)
Rich if your engine has battery charging capability then you need the diagram for model #50627 or #50926. The diodes and fuses are shown.
Chuck
seahorse posted 08-21-2013 06:45 PM ET (US)
http://www.marineengine.com/parts/johnson-evinrude-parts.php?year=1961& hp=75&model=50627&manufacturer=Evinrude§ion=Junction+Box+And+ Switchplate+Group
jimh posted 08-21-2013 09:50 PM ET (US)
In the link given by Seahorse (above, and also many thanks for it,) the item marked with CALLOUT 21 is clearly a fuse, but, in case there are doubters, in the parts listing below the illustration, the part is listed as a fuse. I think we are making progress on the solution of the mystery.
Binkster posted 08-22-2013 08:09 AM ET (US)
I wish I could be of more help but my electrical knowledge in general is very limited. Apparently there are two junction boxes made for this engine, and I posted a link for the wrong one. This 1961 Evinrude Starflite 75 V4 was built in two forms. The one I have (Unicharger model with an alternator in or under the flywheel) and a magneto model, common for that year outboard. I bought this engine with no wiring harness. I bought a wiring harness with the junction box, from a fellow on eBay who was parting out the same engine, except it was a magneto model. I am sure of that becuase I also bought the parts needed to convert my Unicharger engine to a magneto engine if need be. At the time I didn't know if the Unicharger was any good, but when I got the engine started it ran well. So I'm pretty sure I'm running a Unicharger engine with a magneto junction box. I don't really know what all this means, but this afternoon I'll pull the cover off the junction box, and check it out.
rich
jimh posted 08-22-2013 08:54 AM ET (US)
I am not familiar at all with the engine, but it sounds to me like the fundamental difference between the two models is in regard to having battery charging output. The model without battery charging output must be creating its own electricity to run the spark ignition without any sort of attachment to the battery, and the battery is just employed for cranking the engine.
Binkster posted 08-22-2013 10:05 AM ET (US)
Please negate my last post. This morning I pulled the junction box out from under the enclosed rear deck, and on the cover it read Electric Starting Unicharger. I'm thinking now that the EBay seller had another engine that the magneto parts came from. This afternoon I'll remove the cover and take some pics. and try to find the fuse. All I know about OMC's Unicharger is 1961 was the introductory year for this feature, it is setup very similar to automobile ignition of the '60's, with a points distributor. When I first took this boat to a AOMCI meet three years ago, another member told me he had an Evinrude 75 with the Unicharger ignition and it was bullet proof. OMC was trying to keep their sales lead over Mercury and developed several new features including electric (Selectric) shifting which my motor doesn't have.
This outboard comes from upper MI. and apparently saw little use. I converted it to a short shaft, by removing the 5" spacer in the midsection, and installing a 5" shorter, short shaft driveshaft. Try doing that with a Merc. The motor started easilly but ran a bit rough, but a new plastic float, original was cork, and some Sea Foam, and new J4J plugs, and it runs like new. I was upset when I saw what I had done (hooking the battery up backwards), but hopefully all is good cause I really like this engine.
Binkster posted 08-22-2013 06:06 PM ET (US)
Took the cover off the junction box and found a 20amp fuse. A thunderstorm started closing in, so I'll have to wait for tomorrow to check it out.
rich
Binkster posted 08-23-2013 11:55 AM ET (US)
Checked the 20 amp fuse in the junction box this morning. It was just a simple glass covered fuse that was good.
rich

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Author	Topic: Electric Start Motor Direction of Rotation
Binkster	posted 08-18-2013 02:32 PM ET (US) Explain this one to me; I offer no excuses: I have owned electric-starting outboards from the 60's. I have a 1959 14' Sea Fury powered by a 1961 Evinrude Starflite 75hp V-4. I run the boat usually every month at the AOMCI meets. The engine runs flawless, but last month the tach wouldn't work. I couldn't find any broken wires. The ground for the tac runs to the common ground and the positive lead attaches to the positive post on the battery. I normally disconnect the ground cable when the boat is not in use. So this morning I decide to start her up on the hose and run the carbs dry as I usually do. I discover I have the cables hooked up backwards. Red tape wrapped around the positive cable was hooked to the ground post and ground hooked to hot post. Also tac positive wire hooked to ground post. I ran the boat like this at the last two meets. No wonder the tac wouldn't work, but why did the engine start and run as usual with no apparent damage. I straightened out all the wires, engine runs good and tac works fine. I can understand that but I always thought hooking cable up backwards would do damage. I have never done this before, am I losing it?? rich
Binkster	posted 08-18-2013 03:21 PM ET (US) This engine doesn't have a magneto ignition that was common to outboards of that era, it has what they call a Unicharger ignition, same as on autos of the 60's. rich
contender	posted 08-18-2013 04:17 PM ET (US) Bink: I know it sounds crazy but since the cables were hook up backwards, how come the battery did not spark right away when you hooked the cables back to the post?. I have also heard hooking up the cables backwards would blow the diodes in the tach. I guess you have been blessed, but like you said how in the hell did it fire up? Are you sure the wires are right on the starter? still does not make any sense...
Binkster	posted 08-19-2013 09:20 AM ET (US) No. the cables did not spark when they were hooked up backwards. The antique boat does not have a dedicated battery. The battery I use in the antique boat, is the battery, which is fairly new, out of my 13 ft. Whaler. I only run that boat at the antique boat meets, and since I have not been using my Whaler this summer, When I put the battery in the antique boat in July, I just left it there. I ran the boat with the battery hooked up backwards for about an hour in July, and about an hour last saturday. thing is, the battery is even fully charged. rich
conch	posted 08-19-2013 11:22 AM ET (US) I think that motor could be started in the opposite direction of its normal rotation and run. Mercury back then shifted between forward and reverse that way ,and OMC first offered counter rotation running one engine in opposite crankshaft direction. I would think though that you would notice as soon as you put the motor in gear. Parts that may have been ruined may be in your junction box where your solenoid is. Do you have the optional under flywheel alternator? More things to cook in the junction box then.
jimh	posted 08-20-2013 03:29 PM ET (US) quote: ...why did the engine start and run as usual with no apparent damage...[?] The DC electric motor that is typically used as a starter motor for internal combustion engines is a special type of DC motor, called a series-wound DC motor. The direction of rotation is not determined by the polarity of the DC current flow but rather by the relationship of the phase of the field and stator windings, with the result that such a motor rotates in the same direction even if the polarity of the battery connected to it is reversed. The best explanation--in reasonable terms--of how the DC starter motor works is given in http://zone.ni.com/devzone/cda/ph/p/id/53 where it is noted: quote: The direction of rotation of a series motor can be changed by changing the polarity of either the armature or field winding. It is important to remember that if you simply changed the polarity of the applied voltage, you would be changing the polarity of both field and armature windings and the motor's rotation would remain the same. In connecting a battery with the polarity reversed, the DC starter motor would have run in the normal direction. The engine would have been cranked over in the normal direction. The engine probably started and ran on its own magneto power.
conch	posted 08-20-2013 05:31 PM ET (US) I was thinking permanent magnet field coils. Then the coil, condenser, and solenoid etc. also functioned with reversed polarity. Maybe the alternator too if he has one. Rich said he had the coil model not the magneto. Chuck
seahorse	posted 08-20-2013 06:04 PM ET (US) The distributor ignition uses an alternator and a series of diodes plus a fuse. The fuse usually blows on reverse polarity and sometimes the diodes are damaged and other times they are OK. The fuse is a small square up on the flywheel guard if I remember correctly after all these years. It consists of 2 small ceramic squares and a link that goes from one to the other.
conch	posted 08-20-2013 06:18 PM ET (US) The starter would not work in reverse anyway as the bendix wouldn't engage the flywheel. But it would spin real good. Chuck
jimh	posted 08-21-2013 08:49 AM ET (US) The connection of the battery to the engine electrical wiring other than the starter motor is usually through a fuse. The fuse would probably blow with a reversed polarity connection. This would leave the battery disconnected from the engine, and only connected to the starter motor when the solenoid was operated. Once the starter motor cranked the engine, the self-powered ignition system would generate spark without the battery being connected, just as it would if you pull-started the motor without a battery.
jimh	posted 08-21-2013 08:51 AM ET (US) By the way, the solenoid coil is happy to operate with the polarity reversed. See http://www.solenoid-valve-info.com/solenoid-valve-coil-polarity.html
conch	posted 08-21-2013 09:20 AM ET (US) Jim what is the self powered ignition system in this case as there is no magneto? Chuck
jimh	posted 08-21-2013 09:46 AM ET (US) Most older outboard engines run without a battery. They typically have permanent magnet alternators that generate electricity by rotating permanent magnets around a fixed coil. Whether or not the motor in this discussion has such a device is unknown to me, but, on the basis that it ran with the battery polarity in reverse, I would tend to think it is capable of generating its own electricity for operating the engine and generating spark. This is quite common in older outboards. They can be pull started and run without a battery. I think you can now have a sidebar discussion on whether or not the word magneto covers permanent magnet alternators in your understanding of electrical terms. Compare your definition with http://www.merriam-webster.com/dictionary/magneto
Binkster	posted 08-21-2013 12:04 PM ET (US) Thinking of hooking up an amp. guage to see if the motor is charging the battery. I'm pretty sure it is as I have run it twice in this condition in the past 2 months, about an hour each time without charging the battery, with no problems. rich
conch	posted 08-21-2013 12:18 PM ET (US) Jim it sounds very much like the modern E-Tec, can be pull started and run without a battery and has a magneto (alternator). Chuck
jimh	posted 08-21-2013 12:56 PM ET (US) If a fuse blew fast enough, you may have avoided any permanent damage from the polarity reversal at the battery.
Binkster	posted 08-21-2013 03:24 PM ET (US) So, I should check the junction box and look for the fuse to see if it is blown. I read somewhere that it isn't a normal looking fuse. My manual has no info I can find on the junction box. It is a metal box about 4"x8" by 3" thick, mounted usually in the boat with a solenoid inside and battery cables running in and out and all other wiring also. I haven't looked inside in about 3 years, since I set it up, but I don't remember anything that looked like a fuse. This juction box was eliminated a few years later, and everything was mounted under the cowling, as in modern outboards. rich
Binkster	posted 08-21-2013 04:50 PM ET (US) Here is a diagram of the juction box for a 1961 Evinrude 75hp V4. Do you see a fuse?? rich
silentpardner	posted 08-21-2013 05:06 PM ET (US) [Essay on how fuses operate deleted because it seemed to end with a self-contradiction. I have deleted this because there is no value in collecting misinformation. For a good reference on how fuses operate, see http://en.wikipedia.org/wiki/Fuse_(electrical)--jimh]
jimh	posted 08-21-2013 06:13 PM ET (US) Whether or not the battery charging circuit of an outboard engine can tolerate the connection of a battery to it with the polarity of the battery reversed depends entirely on the circuitry of the battery charging circuit. Some circuits will not tolerate a reversed-polarity battery, will draw very high current, and that high current will either blow a fuse, if there is one, and there usually is, or damage some circuit element due to the high current flow. Other circuits care not a bit about a battery reversal, and nothing bad will happen, no current will flow at all, and the battery will be, in essence, completely disconnected from the circuit by a reverse-biased diode. The exact circuitry of the engine under discussion is unknown to me. If we can have a component level schematic diagram, we could look into how the circuit may have behaved in this situation. Without the circuit diagram, we can only speculate on how the circuit behaved when the polarity of the battery was reversed. What seems to be evident is the engine has not sustained damage, or at least is appears to not have sustained damage. There is no mystery to why the starter motor direction of rotation was not affected by the battery reversal, and no mystery about why the solenoid operated normally with a polarity reversal. (See the links to explanations of these behaviors. What is evident is that many readers may not have been aware that the starter motor and solenoid would have been tolerant of the polarity reversal and would have operated normally. If there is no fuse, or if there is a fuse and it has not blown, then it appears that the engine has tolerated a battery polarity reversal with no damage, and, in fact, can run with the battery reversed in polarity. However, I don't think the circuitry of the spark generation devices works with a reversed polarity, but, if the battery was effectively disconnected by the action of diodes in the circuitry, then the engine just ran as it would have when no battery was connected at all. This is not a surprising outcome, as many outboard engines will run without a battery, and in older outboard engines this characteristic is fairly common.
seahorse	posted 08-21-2013 06:36 PM ET (US) My previous post mentioned the fuse being on the flywheel ring guard, but that was only for the newer models. The 1961 alternator equipped 75's had the diodes and fuse in the boat mounted junction box. Here are links to the parts book. http://www.marineengine.com/parts/vintage-evinrude-johnson/FORM_2104/ catalog.html?http://www.marineengine.com/parts/ http://www.marineengine.com/parts/vintage-evinrude-johnson/FORM_2104/ catalog.html?http://www.marineengine.com/parts/
seahorse	posted 08-21-2013 06:42 PM ET (US) I guess Marineengine.com does not allow direct links to their parts pages. Just click on Evinrude, then the year, then your model no. or the Johnson V4A-13 model. The fuse is item #81 part number 379788 on the alternator junction box page.
conch	posted 08-21-2013 06:45 PM ET (US) Rich if your engine has battery charging capability then you need the diagram for model #50627 or #50926. The diodes and fuses are shown. Chuck
seahorse	posted 08-21-2013 06:45 PM ET (US) http://www.marineengine.com/parts/johnson-evinrude-parts.php?year=1961& hp=75&model=50627&manufacturer=Evinrude§ion=Junction+Box+And+ Switchplate+Group
jimh	posted 08-21-2013 09:50 PM ET (US) In the link given by Seahorse (above, and also many thanks for it,) the item marked with CALLOUT 21 is clearly a fuse, but, in case there are doubters, in the parts listing below the illustration, the part is listed as a fuse. I think we are making progress on the solution of the mystery.
Binkster	posted 08-22-2013 08:09 AM ET (US) I wish I could be of more help but my electrical knowledge in general is very limited. Apparently there are two junction boxes made for this engine, and I posted a link for the wrong one. This 1961 Evinrude Starflite 75 V4 was built in two forms. The one I have (Unicharger model with an alternator in or under the flywheel) and a magneto model, common for that year outboard. I bought this engine with no wiring harness. I bought a wiring harness with the junction box, from a fellow on eBay who was parting out the same engine, except it was a magneto model. I am sure of that becuase I also bought the parts needed to convert my Unicharger engine to a magneto engine if need be. At the time I didn't know if the Unicharger was any good, but when I got the engine started it ran well. So I'm pretty sure I'm running a Unicharger engine with a magneto junction box. I don't really know what all this means, but this afternoon I'll pull the cover off the junction box, and check it out. rich
jimh	posted 08-22-2013 08:54 AM ET (US) I am not familiar at all with the engine, but it sounds to me like the fundamental difference between the two models is in regard to having battery charging output. The model without battery charging output must be creating its own electricity to run the spark ignition without any sort of attachment to the battery, and the battery is just employed for cranking the engine.
Binkster	posted 08-22-2013 10:05 AM ET (US) Please negate my last post. This morning I pulled the junction box out from under the enclosed rear deck, and on the cover it read Electric Starting Unicharger. I'm thinking now that the EBay seller had another engine that the magneto parts came from. This afternoon I'll remove the cover and take some pics. and try to find the fuse. All I know about OMC's Unicharger is 1961 was the introductory year for this feature, it is setup very similar to automobile ignition of the '60's, with a points distributor. When I first took this boat to a AOMCI meet three years ago, another member told me he had an Evinrude 75 with the Unicharger ignition and it was bullet proof. OMC was trying to keep their sales lead over Mercury and developed several new features including electric (Selectric) shifting which my motor doesn't have. This outboard comes from upper MI. and apparently saw little use. I converted it to a short shaft, by removing the 5" spacer in the midsection, and installing a 5" shorter, short shaft driveshaft. Try doing that with a Merc. The motor started easilly but ran a bit rough, but a new plastic float, original was cork, and some Sea Foam, and new J4J plugs, and it runs like new. I was upset when I saw what I had done (hooking the battery up backwards), but hopefully all is good cause I really like this engine.
Binkster	posted 08-22-2013 06:06 PM ET (US) Took the cover off the junction box and found a 20amp fuse. A thunderstorm started closing in, so I'll have to wait for tomorrow to check it out. rich
Binkster	posted 08-23-2013 11:55 AM ET (US) Checked the 20 amp fuse in the junction box this morning. It was just a simple glass covered fuse that was good. rich