Force flywheels

pnwboat

Rear Admiral
Joined
Oct 8, 2007
Messages
4,251
I have a question regarding flywheels from different year motors. Will a flywheel from a 1999 120HP fit a crankshaft from a 1988 125HP? I'm looking to upgrade my ignition system from the older 1988 era blue CDI boxes to the late model Mercury type ignition. My concern is the angle of the taper on the end of the crankshaft.
 

Frank Acampora

Supreme Mariner
Joined
Jan 19, 2007
Messages
12,004
Re: Force flywheels

I could not say for sure but I doubt it! The 1999 was a Mercury part and although the crankshaft taper is the same, the flywheel itself appears to be a little smaller. The magnets inside also are different to accomodate the Merc stator and ignition.
 

pnwboat

Rear Admiral
Joined
Oct 8, 2007
Messages
4,251
Re: Force flywheels

I found one on line and from the pictures, the slot for the keyway in the 1999 flywheel appears to be cut differently. In my 1988 flywheel, the keyway slot is cut all the way from the bottom of the hole to the top. In the 1999 it doesn't appear to go that far. Looks like it stops about halfway up the hole. If it is a different diameter then I suppose that the starter engagement will be a problem. I guess it all depends on whether or not I feel like taking a chance and spending the cash to find out.

Thanks for your input Frank.
 

Frank Acampora

Supreme Mariner
Joined
Jan 19, 2007
Messages
12,004
Re: Force flywheels

The ring gear is the same diameter and the starters are the same. It is the inside that appears smaller. So while it will in all probablilty fit on your crankshaft and the starter will engage it, it MAY interfere with your existing stator.

That's a gamble I would take to find out the answer only if it were cheap enough. But my limit would be about 20 bucks plus shipping, figuring that somewhere down the road I would find a use for it.
 

maxumlemon

Cadet
Joined
Jul 18, 2008
Messages
6
Re: Force flywheels

it will defenetly throw off your sator not being lined properly. but if shaft addaptments are the same it will turn, No?
 

IMPATIENT 1

Seaman Apprentice
Joined
Feb 10, 2009
Messages
45
Re: Force flywheels

The ring gear is the same diameter and the starters are the same. It is the inside that appears smaller. So while it will in all probablilty fit on your crankshaft and the starter will engage it, it MAY interfere with your existing stator.

That's a gamble I would take to find out the answer only if it were cheap enough. But my limit would be about 20 bucks plus shipping, figuring that somewhere down the road I would find a use for it.

20bucks for a 99 120hp flywheel:eek: let me know if ya don't go that direction, i'll buy it for a back up. i just spent 272 for a new flywheel for my 98 120hp force, and that was almost half price , i found a old p# flywheel in someone stock and got a deal on it.
 

pnwboat

Rear Admiral
Joined
Oct 8, 2007
Messages
4,251
Re: Force flywheels

I picked up a late model stator (one of those red ones) and I compared it to the 1988. While the outside diameter is (as far as I can tell) the same, the inside diameter is not. Late model stator is thicker, so the opening in the middle is smaller which moves the mounting holes closer to the center of the opening. You can't mount the late model stator on the 1988 end cap. I had to pick up a late model end cap (with the upper crankshaft seal). Not sure what year it is but it fits the late model red stator. Both 1988 and late model end caps have the same bolt pattern to mount to the block.

I saw a deal and took a chance. I picked up the stator, trigger, regulator and 4 coils with mounting plate off a 1999 120HP for 50 bucks a couple of months ago. Just need a flywheel now.

Also need to figure out how to wire it up to a 1988 wiring harness. I'll cross that bridge when I get there.
 
Top