Half Power/Flywheel Magnets Broken

[arkansascabincruiser]

I have a 1988 Johnson 200hp GT V6 (model J200STLCCM). The boat felt like it had lost half of its power. When I got it home almost all of the bolts under the flywheel were lose or had fallen out (where the stator/timing parts assembly mount to the engine block). I tightned all of the lose bolts, and tested my spark plugs and wires. Some of them were not getting spark. I pulled the flywheel and half the magnets were broken and the pieces had fallen thru to the bottom to the engine shroud. The stator looks to have no physical damage. Will replacing the flywheel fix the firing problem if nothing else is damage? Is there a way to replace the magnets only and not the entire flywheel? Thanks in advance for your guidance.

 

[Dhadley]

Re: Half Power/Flywheel Magnets Broken

Welcome. You can replace just the magnets. Any OMC / BRP dealer can supply the magnet kits or do it for you.

 

[arkansascabincruiser]

Re: Half Power/Flywheel Magnets Broken

Would the magnets being broken cause the bolts that I described to come lose? Will this fix the firing issue if no other issues exist? Thanks

 

[Greg_E]

Re: Half Power/Flywheel Magnets Broken

Take the loose bolts out , clean them, and reinstall them using some medium strength Loctite, or similar product, so they don't loosen up again. They may have loosened up when the magnets came loose, causing an unbalanced condition with the associated vibration.The epoxy that was originally used, was not up to the job. The epoxy that is used now is Hardman epoxy for wet surfaces (purple bubble pack). It comes in the magnet replacement kits, but if three of the magnets are intact, you can just remove them and use the new epoxy. If you leave them as is with the old epoxy, they wil probably fail in the future, sometimes causing catastrophic damage. If your stator and timer base weren't damaged you were lucky. The magnets are extremely brittle, so you need to be careful when you remove them. You will also need to fabricate some type of spacers to separate the magnets while the epoxy hardens. Also, I would mark the location of the magnets and replace them as close as possible to there original location. Note the drill holes on the bottom side of the flywheel to balance it.
After replacing the magnets, I had my flywheel rebalanced at an automotive machine shop. I don't know is if that's absolutely necessary, but I've never had a problem with it again.

 

[Faztbullet]

Re: Half Power/Flywheel Magnets Broken

The 1988-1993 engines were bad about this. The correct fix is to install 1/8 inch longer bolts and blue loctite. Was told by OMC rep that cause was harmonics due to running extended periods in the 3000-4000rpm range. Here is the repair kit for flywheel. Make sure all shards are removed as they will stick everywhere and even had a cutomer with a engine fail from ingesting particles. A 3/8 bolts work great as a spacer between magnets. Also broken magnet will cause ignition problems as charge coils and power coil will not generate proper voltages. Here is link to magnet kit to repair you flywheel.
www.promarineusa.com
Flywheel Magnet Kit
part #4304

Kit containing 1 magnet and the epoxy to install it for OMC Looper flywheels.
$14.75