1970 25hp evirude flywheel

excalibor1967

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What flywheels will possibly work on this motor. I have flywheels from a 1976 johnson 20hp, and a 1961 18hp evi. Will one of these work? Thanks.
 

excalibor1967

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Re: 1970 25hp evirude flywheel

Thanks for the tip, but allready tried that..they do not even list the flywheel or part number for a 1970 25hp...
 

wilde1j

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Re: 1970 25hp evirude flywheel

They don't list it BC it's no longer available. An old time dealer with a paper parts list would have the number.
 

jbjennings

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Re: 1970 25hp evirude flywheel

I feel pretty confident that the '61 18hp flywheel will fit on your '70 25hp. However, I'm not absolutely certain by a longshot. If you have them both, why not just compare them? I'm thinking the block for a '70 25hp is pretty much the same as the 18hp block, and they didn't change much for many years. Isn't the '70 25hp the last year of the lightweight 25hp OMC's?
Good luck,
JBJ
 

excalibor1967

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Re: 1970 25hp evirude flywheel

Thanx JB, not sure if 70 was the last year 4 the lights, but yes, the blocks are the same , both 22 cubes, i think. I do not have the original flywheel on 25hp, was missing when i purchased..I know the 18hp flywheel will physicaly fit the 25, just wasnt sure about magnet placement...Probably no different though. Funny thing is, i cant even find a part # for the 25 flywh. No site lists
it. Shows it in diagram, but not offered at all, as if it never existed....sorta like my johnson 20hp 1976, it to is not listed in 1976, only 73 and 80s. (lol)
aint it grand to have something that was never made!!!..
 

F_R

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Jul 7, 2006
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28,195
Re: 1970 25hp evirude flywheel

Thanx JB, not sure if 70 was the last year 4 the lights, but yes, the blocks are the same , both 22 cubes, i think. I do not have the original flywheel on 25hp, was missing when i purchased..I know the 18hp flywheel will physicaly fit the 25, just wasnt sure about magnet placement...Probably no different though. Funny thing is, i cant even find a part # for the 25 flywh. No site lists
it. Shows it in diagram, but not offered at all, as if it never existed....sorta like my johnson 20hp 1976, it to is not listed in 1976, only 73 and 80s. (lol)
aint it grand to have something that was never made!!!..

Your 1970 uses a 580866 flywheel and ring gear assembly. The gear does not come off.

A 1961 uses a 580226 flywheel and ring gear assembly and the gear does come off.

I don't know about the 1976. Could that be a commercial or non-USA motor??

Anyhoo, I am fairly confident that the '61 and '70 will interchange. I know for a fact that the tapers and magnets are the same. As long as it isn't electric start there shouldn't be a problem with the ring gear.
 

ditchen

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Mar 18, 2009
Messages
47
Re: 1970 25hp evirude flywheel

One note about the difference between the 70 and 76 models is the ignition system. The 76 has a newer mag setup (identifiable by the coil packs on the cylinders) then the older 70's motor.
 

Chinewalker

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Aug 19, 2001
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8,902
Re: 1970 25hp evirude flywheel

'76 flywheel will not work. It will either have the CDI magneto or the low tension mag. Both are different flywheels than what the '70 will use. Functionally, I think the '60 18hp flywheel will work as long as the crank tapers are the same. They changed crankshafts in '68, but I *think* the taper remained the same...
 
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