ignition type on a 4hp mdl 40 Mercury

[crosbyman]

strangely I look at the ignition coil under the fw and it is almost….. but not exactly a standard magneto coil for a OMC engine

the diagrams do no not show this type of coil in te marineengine.com listings for a mdl 40 my engine is in 269xxx series and sould be USA made.

I did not fully take the ignition aprat so I can’T tell if it hasa set of point …

th capacitor checks out as faulty with my “MOHAT” box looks and test’s like a .020 uf 197 nanoF

anyone recognize the OMC like coil ignition system ??

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[frankr]

I’ve wondered about that.

https://www.amazon.com/s?k=802371&crid=17T83EROQLEP6&sprefix=802371%2Caps%2C133&ref=nb_sb_noss

[crosbyman]

FR.. that is the coil 🙂 $25 cdn money I tagged it in my basket in case…. thanks

anything special about that ignition ??

update; found a good utube on a 9.8 with similar ignition ( magneto) so onward like a OMC engine 🙂

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• This reply was modified 3 years, 6 months ago by crosbyman.

[billw]

I certainly don’t know everything; but I have seen a lot of old Mercurys and never a coil like what Frank’s link has. Are those supposed to bolt onto a Phelon mag base plate? Phelon laminations are machined while attached to the base plate; so when you change a Phelon coil, you usually just change the winding assembly, not the whole thing with the lamination. The laminations are also held on by only two screws, not three, which are 1/4-20 thread. In Frank’s link, those are what I think are the Mercury aftermarket part number for an OMC coil. Crosbyman, I would sure love to see a picture of YOUR mag.

Long live American manufacturing!

• This reply was modified 3 years, 5 months ago by billw.

[frankr]

billw wrote:

I certainly don’t know everything; but I have seen a lot of old Mercurys and never a coil like what Frank’s link has. Are those supposed to bolt onto a Phelon mag base plate? Phelon laminations are machined while attached to the base plate; so when you change a Phelon coil, you usually just change the winding assembly, not the whole thing with the lamination. The laminations are also held on by only two screws, not three, which are 1/4-20 thread. In Frank’s link, those are what I think are the Mercury aftermarket part number for an OMC coil. Crosbyman, I would sure love to see a picture of YOUR mag.

• This reply was modified 3 years, 5 months ago by billw.

Those are my thoughts also. Looking forward to a picture.

[crosbyman]

coming… see preliminary shot from a CLymer book showing the OMC like coil top left corner of the book scan

I have one coil one condenser…. will open it up today to see I find a single point set under some cover

btw the Merc coil would not fit a OMC mag…. bolt holes do not line up this is pure Merc stuff.

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• This reply was modified 3 years, 5 months ago by crosbyman.

[dave-bernard]

That looks like a phase maker ignition.

[crosbyman]

here are pics of the ignition…. basically nothing complicated 🙂 one set of point to be touched up …..one condenser (to be replaced) and one coil…. testing good…for now !

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[frankr]

Very educational. Thanks for posting the pics.

[crosbyman]

I realy searched Marine engine site, google for parts on the 4hp ignition … out of interest purely.

Can’t find much other than some older posts about the fragility of the points assembly (rocker arm and cracks within).

I looked at various mdls finding nothing ??? serial # points to a US made engine . year unknown

I have some .020uf mylar (630v) condensers. Mr.Mohat Outboarder article showed preferences for 800V tolerant condensers but i’ll try 630v caps ( his oscilloscope traces did not go much higher than 275V on the EMF kickback traces of the coils .

lakes frozen solid so this will take a while to test out 🙂

thanks all for feedback

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• This reply was modified 3 years, 5 months ago by crosbyman.

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