Force 85 1989 flywheel magnet pain

D

dougrie

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Mar 16, 2021
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So, it's back to the boat for me - late start to the season due to a pile of DIY.

I spent most of last season trying to coax the engine to run, eventually pulling the flywheel and discovering two magnets had turned to powder. It looks odd though. This flywheel seems to have six individual magnets with spaces between them, whereas the photos I see online of 1989 85 flywheels have a continuous magnet. Do I have the wrong flywheel fitted?

A couple of related questions... can anybody tell me what resistances the stator coils should have? I need to check whether it's still alive.

And... can anybody tell me what orientation/polarity the magnets in the fly should have, so I can check the ones that are left and figure out a plan?
 
N

Nordin

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Jun 12, 2010
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If you have six individual magnet your engine has the Mercury Thunderbolt ignition.
The Prestolite system has a magnet strip.
You can find the spec for the stator at outboardignitiondotcom.
 
jerryjerry05

jerryjerry05

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Pics of the motor, flywheel and ignition(packs/coils)and lower unit.
It sounds like your motor is a lot newer than 89.

Not sure but the flywheel shouldn't fit an older motor.

Magnets if they're coming apart then you'll probably need a new flywheel.
 
D

dougrie

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Hey @jerryjerry05 sorry for the long pause...

I think this is Frankenstein's own outboard. The block is marked 8569XF which indicates a 1989 Force 85 but various parts, including the lower unit, don't match the schematics for that model; and it's sitting on Tohatsu motor mounts. It's... imaginative. The flywheel has (had) six individual magnets unlike the original flywheels. So I assume somebody has replaced the entire ignition setup at some point with a more recent one.

I attached a couple of pictures of the flywheel. No markings on the upper surface other than a warning about starting. The inside has markings 15JO, CC2148, 3, and KIC1. The stator is marked 398-9710A14 and 3300. I don't see any markings on the ignition modules themselves.

Any idea what kit this is?
 

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N

Nordin

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That ignition system is the one Mercury started to put on the Force engines in I believe 1991-92 (Thunderbolt ignition).
It has a more reliable reputation then the Prestolite system which the engines was equipped with before.
In my opinion the Prestolite system was as good as the Thunderbolt but parts are easier to find for the Thunderbolt such as CDI (Switchboxes) triggers and coils.
I do not know if a flywheel from a mid 80-90.es Mercury 3 cylinder 50, 60 and 70Hp which has the same system.
The taper in the flywheel can be different between Force and Mercury.
Check out Ebay for a flywheel.
BTW. Are the magnet/magnets who are loose still intact?
If they are, try to glue them back with super glue or epoxi glue.
 
D

dougrie

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Thanks - great information. Unfortunately one of the magnets disintegrated. The other two are still good. So if I can find a compatible magnet, I can re-glue as you suggest.
 
jerryjerry05

jerryjerry05

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That flywheel and ignition is from a lot newer motor.94-99
Someone changed it over??
Pics of the gear housing?
 
D

dougrie

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Mar 16, 2021
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Ok, so, a million thanks to everyone here and also to Pat at Pine Lake Parts who managed to source me a replacement magnet! The motor is a bit of a mix and yes, @jerryjerry05 and @Nordin you were right, the flywheel/stator is from a later Mercury.

Now I need to fix the thing in, along with the others that came loose. Scrub the inner surface clean, then some Marineweld, will that do it? And, three magnets have not detached - should I leave them alone? If not, how would you recommend removing them without breaking them?
 
N

Nordin

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Yes as jerryjerry says.
Do not remove the magnets that are in place.
Just glue the loosen magnets back.
 
J

Jiggz

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Oct 23, 2009
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Loctite 326 is commonly used for ferrite material bonding. You might want to research it.
 
R

Redbarron%%

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Dec 7, 2017
Messages
479
I have always used JB Weld, liquid steel, but I figured that since it was glued to the steel (iron?) flywheel it would be OK.
Be sure the thoroughly clean the magnet and the flywheel as most of these turn loose due to corrosion getting behind the magnets.
I can't swear that they are as efficient and as strong as original, but at least the flywheels seem to work OK. Don't ask about the balance.
 
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