Flywheel magnets 1999 90 hp Tracker (Mercury Marine)

craazy

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Was out on the lake running the boat this morning, made my first run and when I started to let off the gas to come off plane, it felt like something with the hot foot broke and the motor shut down before I came off plane. Started looking around, eventually pulled off the cowl and found that the little plastic piece on my trigger arm that connects to the trigger, under the stator and flywheel had broken. Got home, pulled off the fly wheel and found that one of the magnets had broken and part of it came unglued. (The magnet is broken into two pieces. One piece had come unglued and was stuck to the stator when I pulled the flywheel off) One of the other magnets has a small crack and another has a very tiny piece of it chiped off. My question is, would any of you suggest trying to repair that broken magnet and carefully trying to bond it back to the flywheel in it's exact position as it should be with a good epoxy (JB weld?) before throwing the money at another flywheel?
 

Frank Acampora

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It has been done before if the magnet is in decent condition. With a new flywheel running 800 plus bucks and who knows what for a used one, it makes sense to try. Understand though that the clearance between the magnets and stator or trigger is very tight, Too much epoxy and the magnet will rub.
 

craazy

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Thank you for the quick reply. I will probably need to try and see if I can get it repaired before getting another. What kind of bonding agent would you recommend? I have used JB weld on other things (non boat related) and it seems incredibly strong. I would think a very thin layer of it would hold the magnet in place. Hopefully it won't be too tricky to get the magnet positioned right to leave enough room between it and the stator.
 

HotTommy

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Food for thought: If I did my math right, a one ounce weight on the edge of a 10" disc spinning at 5500 RPM is trying to pull away from the disc with a force of 265 pounds. I don't know how much your magnet weighs nor how big your flywheel is, but I suspect it is going to take a mighty powerful adhesive to hold it. ... Oh it also occurs to me that you may change the balance of the flywheel if your repair isn't real close to the original. .... I'm not trying to talk you out of trying the repair. I'm just pointing out that there are many ways this might go badly. (I had to replace my flywheel for lost magnets last Spring).

And my stator.
 
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craazy

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Yes, thank you for pointing that out. Everything has to be near perfect on this kind of stuff. I'm afraid I would do something wrong. Which brings me to my next question. I've been looking around quite a bit already for used flywheels. I found one for a 1994 tracker force that looks identical. Would a '94 fit and work on a '99 motor? Or would there be complications? As far as serial numbers go, the first three numbers and the very last didgit (which is a letter) is the exact same between the two flywheels.
 

pnwboat

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You need a flywheel that is used for the Mercury CDM Thunderbolt ignition system which was used on the Force motors beginning around late 1995, early 1996 all the way through 1999. The flywheel has a lip around the center hole and is threaded internally for a puller. The center hole is also larger in diameter than the pre-1995 flywheels. If the flywheel that you're looking at has the lip with threads, and the center hole for the crankshaft snout is the same size, then it might work unless it's for a two cylinder motor. The flywheels for the two cylinder motors have a different set of trigger magnets (not stator magnets) around the center hole under the flywheel and usually have a sticker that states that it is for a 2 cylinder motor only.

You can also look at the used Mercury flywheels on the auction sites too because they used the same flywheel on some of their motors around that time frame.
 

sjbs

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I bought a 120 Force power head for parts from a guy on ebay that had a magnet come loose and wedge under the flywheel and it broke the top of the crankshaft.If I were you I would find a used one.Force #9008A54 or Mercury #261-859236T14.
 

craazy

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Thank you guys for all the good information. I will keep looking around.
 

gm280

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I had a similar situation happen to my lawn mower where a Kohler engine flywheel magnet slung off. And reading about it, seem that is a frequent thing to happen on that engine. And they stated to glue the magnet back using JB Weld two part epoxy. So I did that and everything worked perfectly since. And yes as the distance from the center goes further out, the edge speed is greater and therefore the centrifugal force increases as well. BUT, since the magnet is attached to the inside of the flywheel, that force actually works in your favor pushing the magnet tighter to the flywheel. So with all that stated, I'd glue the parts back together using JB Weld and boat on... I don't see much problems if they all are glued back properly. JMHO! :)
 

craazy

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Here is the flywheel that I found that had supposedly come off a '94. Zooming in on the pictures, it has a lip like mine, and threads down the center hole. Hard to tell if the center hole is the same size, judging by the picture. The bottom of this flywheel looks identical to mine and the magnets look to be in great shape. Is there anything I should be aware of before I make a purchase? Thanks again to all of you guys that are willing to help me out.
 

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craazy

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Here is my flywheel.
 

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Frank Acampora

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While they do look alike, appearances can be deceiving. That looks like a part number in white marker. Simply call Mercury customer service and ask if it is correct for your engine. Go onto their website and find the number or even email your question. Every time I have called them, they have been very helpful.
 

jerryjerry05

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This last fall, one of my customers was having trouble.
91/ 75 Mercury. Almost the same flywheel you have.
Turns out there was a few things wrong.
The regulator was bad along with the tach and 2 magnets had come loose.
The reg and tach were just a remove and replace.
The flywheel I used Gorilla Glue.
I cleaned up the old glue and replaced 1 magnet at a time.
Wedging them in place so the excess glue was smooshed out.
An old small turnbuckle worked fairly well.
Clean off the excess glue before it dries as it's pretty tough to clean after it's dry.
It scraped the stator but still works.
 

craazy

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Thanks again. I contacted Mercury and they gave me a list of part #'s for flywheels that will work on my motor. jerryjerry05, thanks for pointing that out. So are you saying that a bad electrical part caused a chain reaction and caused trouble with the flywheel on one of your customers motor? It seems that there is a short in my small ground wire around where I have the trim/relay assembly set up, which runs by the starter and solenoid. I had just recently fiddled around with it because I wasn't getting any power at the dash, but my trim was working just fine. Found that the screw was loose where the wire grounds to the motor. Tightened it, and got my voltage gauge back up, but didin't have enough power to turn the starter. Lightly wiggled a few of the smaller wires around the trim/relay assembly and she cranked up just fine. I imgagine now that this may have something to do with slinging a magnet on my flywheel?
 

Frank Acampora

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No, completely different problem! Flipping off a magnet is simply a failure of the glue holding it OR something getting under the flywheel, interfering and forcing off the magnet.
 

jerryjerry05

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Heat, age and cheapo glue.
Possible something got in there?
The connection problem needs to be really looked into.
Replace all connectors.
 

craazy

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I found a good used flywheel and trigger locally at a very good price. Motor is running now, but is missing and cutting out some. I'm no expert, but I imagine this may be due to the timing after putting a new trigger and flywheel on there, plus fiddling around the piece that hooks up to the trigger arm. So that's next on the list. We'll try to get the timing set up right on it, hopefully that will take care of everything. BTW, we figured out the electrical issue tonight as well. After playing around with all the wires, we pin pointed which one it was. Turned out that the nut that holds the big ground wire from the battery was loose. I didn't see this previously as it's located under all of the wires and solenoid. Hopefully we'll be up and running after we get the timing right. Thanks again for all of your help fellas.
 
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