Cross referencing armature plates

raver_jay

Recruit
Joined
Jan 4, 2008
Messages
3
New to the forum here and need some advice.

I have a 1976 40 hp Johnson (model 40r76). The coil snapped inside the flywheel and destroyed the armature plate. The armature plate on it is stamped 580360.

I found a 1970 Johnson 40 Hp armature plate from model 40 ES. armature plate stamped 580867

Will this plate work on my motor? also, how do u set the timing on these when replacing the flywheel?

Any advice is much appreciated.
 

tashasdaddy

Honorary Moderator Emeritus
Joined
Nov 11, 2005
Messages
51,019
Re: Cross referencing armature plates

go here look up parts numbers, follow prompts to motors. then go to ishopmarine.com enter the numbers if they direct you to the same replacement #, they are the same. flywheel is line up by the key way. shaft and flywheel clean a free of any oil, or substance. torgue to specifed #, or you will shear the key, and throw it out of time.
 

raver_jay

Recruit
Joined
Jan 4, 2008
Messages
3
Re: Cross referencing armature plates

I checked every armature plate for the 1976 40 hp and they all said it was part #581217 but my motor was running with plate #580360. I searched everywhere for this part # (580360) and cant find where it came from.
Obviously it has been replaced so now I'm still wondering if 580867 will work?
 

jim kinser

Petty Officer 3rd Class
Joined
Nov 17, 2007
Messages
94
Re: Cross referencing armature plates

Try going to <brp.com> , they show what your looking for.
 

tashasdaddy

Honorary Moderator Emeritus
Joined
Nov 11, 2005
Messages
51,019
Re: Cross referencing armature plates

make sure the number on the core plug matches. if the power head had been changed this is the model number for the engine.
MVC-859S-1.jpg
 

jim kinser

Petty Officer 3rd Class
Joined
Nov 17, 2007
Messages
94
Re: Cross referencing armature plates

Found this info on ebay,
Where Used: [0580867 (ARMATURE PLATE, Sleeve and post)]
33E70M 1970-->MAGNETO GROUP
33EL70M 1970-->MAGNETO GROUP
33R70M 1970-->MAGNETO GROUP
33RL70M 1970-->MAGNETO GROUP
40002A 1970-->MAGNETO GROUP
40003A 1970-->MAGNETO GROUP
40ES70A 1970-->MAGNETO GROUP ELECTRIC SHIFT
40ESL70A 1970-->MAGNETO GROUP ELECTRIC SHIFT
40R70A 1970-->MAGNETO GROUP
40RL70A 1970-->MAGNETO GROUP
 

jim kinser

Petty Officer 3rd Class
Joined
Nov 17, 2007
Messages
94
Re: Cross referencing armature plates

More info from BRP,

Where Used: [0580360 (PLATE, Armature)]
6002B 1970-->MAGNETO GROUP
6003B 1970-->MAGNETO GROUP
6102E 1971-->MAGNETO
6102G 1971-->MAGNETO
6103E 1971-->MAGNETO
6103G 1971-->MAGNETO
6202D 1972-->MAGNETO
6203D 1972-->MAGNETO
6402C 1974-->MAGNETO
6403C 1974-->MAGNETO
6504R 1975-->MAGNETO
6505R 1975-->MAGNETO
6902M 1969-->MAGNETO GROUP
6903M 1969-->MAGNETO GROUP
 

HighTrim

Supreme Mariner
Joined
Jun 21, 2007
Messages
10,486
Re: Cross referencing armature plates

Item [BMC-0580360] has been superseded with item [BMC-0584810]

I dont believe item 580867 will work, different price and stock according to ishopmarine.
 

raver_jay

Recruit
Joined
Jan 4, 2008
Messages
3
Re: Cross referencing armature plates

Its weird that the plate that was on my 40 hp (580360) worked even though it came of of a 6 hp.
 

F_R

Supreme Mariner
Joined
Jul 7, 2006
Messages
28,226
Re: Cross referencing armature plates

I think you will find that there are actually only a few different OMC armature plates. And even then, the differences are in various holes drilled and tapped--or not. The later model 40 hp motors had different mounting rings. The very early models were slightly different on the OD. And there were the ones with external coils.

Except for the very early ones and the external coils ones I think you will find them all to be intrchangeable by paying attention to the drilled or not-drilled holes. And of course you would have to swap the complete plate and mounting rings if applicable.
 
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