Flyaway Flywheel Magnets - Puller details? Reattachement procedure?

[Daibheid]

First off I'd like to once again pay tribute to the wealth of information and experience made available here by so many experts. Once again determined research of previous posts has given me the information I needed to track down a problem I've never heard of on any engine. <br /><br />I'm trying to get a 3cyl 75 Mariner autolube ca '90 vintage running after being winterised for a couple of seasons. After removing and sorting a stuck starter and bendix I got the engine turning OK and fuelling but no spark. I tracked at least one issue down using the info I got from previous posts to something I'd never have suspected - magnets detached from the flywheel.<br /><br />I now need to get it off but my local dealer is not inclined to loan or even rent out his flywheel puller. Could one of you help me out with the details of the puller threads so I can get one made. I just know it'll be quicker and cheaper than waiting for one to be freighted to Ireland.<br /><br />I imagine the chances a conventional three jaw puller would do it are slim especially as rain has got on the nut and puller threads and rusted 'em. These are currently marinating in WD40! (Should there be a rubber insert or something to stop this although my older Premix 70 3 cyl has the same rain trap but the cowling does a better job of keeping the water out.)<br /><br />If anyone has had this problem before where most but not all the magnets came loose, did cranking the eninge cause damage underneath the flywheel? I'm anxious the one or two remaining fixed magnets might have pushed the loose ones....<br /><br />I've read on here that epoxyng them back in if done correctly can work for years so I'd appreciate any advice on what off the shelf epoxies have worked. I'd hate to have to get a new flywheel especially as it or a used replacement could just as easily develope the same problem.<br /><br />Again thanks for even taking the time to read the post and great if you experts can help with the puller thread diameter and details (eg form and TPI) and any otehr comments on the above.<br /><br />Happy boating!

 

[Daibheid]

Re: Flyaway Flywheel Magnets - Puller details? Reattachement procedure?

Anyone hoping to get some help on this type of problem should take a look here:<br /> http://www.outboardrepairs.com/flywheel/ <br /><br />Looks like any reputable 2part epoxy will do the job and teh key is surface preparation.

 

[Laotzu]

Re: Flyaway Flywheel Magnets - Puller details? Reattachement procedure?

The Merc manual I have says that if the magnets are loose or cracked, buy a new flywheel. I would imagine that the placement of the magnets has to be very precise for correct firing. But, when you remove the flywheel, don't forget to use a cap on the end of the shaft when you screw down the puller, Otherwise it will damage the shaft. Then you'll have to replace the shaft too.<br />Good luck.<br />By the way, about 60% of us yanks claim Irish ancestry, But I really am half Irish.<br /><br />Jerry

 

[Daibheid]

Re: Flyaway Flywheel Magnets - Puller details? Reattachement procedure?

Hi Jerry,<br /><br />Loose is clearly dangerous although the magnets are strong enough to ensure they don't drop down and centrifugal force should keep them in place if it starts. Cracked magents would add a few new poles and pulses into the equation - definitely bad news.<br /><br />Regarding magnet placement, I think as long as they're reasonably well equi-spaced apart there should be no problem. As I understand this system, the outer magnets are for the stator and just charge the capacitors and therefore are not 'timed'. The inner magnets drive the trigger to fire the caps and are therefore pretty important in terms of timing.<br /><br />Thanks for teh caution on the flywheel/shaft but I've since removed and refurbished the flywheel but still no spark so now it's meter time....<br /><br />Half Irish is good!<br /><br />D