4 HP Evinrude Coils

[scimitar858]

Hi. I have an early 80s 4hp Evinrude outboard, on which the coils have stopped working. The ones fitted have the number 510961 stamped into them but i can't find any replacements with this number. Were they superseded with a different part number, or is there another number that will suffice? Thank you in anticipation.

 

[Sea Rider]

What's the precise model and year of manufacture ?

Happy Boating

 

[Crosbyman]

well... the 1982 4hp uses good old 0584477 available everywhere including china but....

coils (2) just don't "stop working" tell us more before spending good money .

cracked ??

what ohms do you measure from the secondary High voltage pin and primary wires (usually 4-7 Kohms)

what ohms do you measure between the 2 primary wires 1 or 2 ohms usually)

did you try cleaning the points? what about condensers (old or new ??)

 

[matt167]

appears that your engine has the old style magneto ignition which was used for a brief time between 1981 and 1982 I think. There was a CDI ignition used before that, and after that but OMC went 50's tech for a couple years there.

The system uses 2 coils, 2 condensors, 2 sets of points and 2 long lengths of solid core ignition wire.. Any combination of bad components here can cause no or weak spark

 

[racerone]

Any pictures of these coils ?----Where are the coils mounted ?

 

[scimitar858]

well... the 1982 4hp uses good old 0584477 available everywhere including china but....

coils (2) just don't "stop working" tell us more before spending good money .

cracked ??

what ohms do you measure from the secondary High voltage pin and primary wires (usually 4-7 Kohms)

what ohms do you measure between the 2 primary wires 1 or 2 ohms usually)

did you try cleaning the points? what about condensers (old or new ??)

Hi. I'm a marine engineer, so knowledgeable and can find my way around an engine. The coils currently fitted are extremely old with cracked casings. One barely registers anything on the dial, and the other registers zero. Hence my question with regards to cross referencing part numbers. Any help with this would be greatly appreciated. Kind Regards Phil

 

[scimitar858]

The offending culprit. Of course, there's nothing to say these are the correct ones fitted to begin with.

 

[Crosbyman]

these coils are common to OMC magnetos for about 20-25 years and have changed numbers across the years so don't worry to much about finding the same numbered coils

it is critical that to avoid any wrong answers from folks helping out on your project that you list the engine model on the plate or post pictures of your oldy...

I have installed several low cost Chineese coils with great success while some swear by OEM stuff. up to you to decide
1.5 - 40HP Outboard Engines Ignition Coil For OMC Johnson Evinrude 584477 582995 | eBay

• Ignition Coil for Johnson Evinrude OMC Lawnboy Outboard Engine Motor Replaces Lawn-Boy 580184 582463 580198 582396 Johnson Evinrude 0582995 0584477 0580416 0582370 0582931 0580971 OMC 584477 580118 580197 580416 582370 582921 582995

your coils should have 1-3 ohms across the 2 primary wires and 4-8 kohms between primary and the high voltage pin

if cracked... replace them ...beats rowing back to shore

 

[Crosbyman]

this is what we all find under old motors like yours although 1980's is not that old for cracking

no offense but 2 bad coils in one motor at the same time is somewhat bad luck ....
make certain you use the proper scale to read low ohm values across the primaries then a higher scale to read 4-8 kohms on the HV pin

barely registering ... is not to common... coils are usually OPEN totally (infinity) Shorted (rare) or grounded to the lamination (also not to frequent) but barely sounds more like a scale issue

btw... what is ZERO .. is it like 0 ohms ===> dead short or 0 reading as in infinity/open ??

pic of a 6hp (same magneto as your 4hp) and pic of a 7.5hp (same magneto after coils replaced.) tuck back all wires away from the rotating shaft !!!)
your condensers need to be replaced and at a bare minimum.. points need to be cleaned and set to .020 on the high point of the cam