35amp flywheel center magnet shifted but not loose -how to remove in one piece??

[guitman32]

The center magnet on my 35 amp flywheel ('89 175 crossflow) seems to have shifted about 1/3" out of position...BUT it isnt really loose to the touch.

Does anyone know how I can loosen this in one piece so I can re-epoxy in position?? Is this even possible?

 

[boobie]

Re: 35amp flywheel center magnet shifted but not loose -how to remove in one piece??

How do you know it has shifted ??

 

[Grub54891]

Re: 35amp flywheel center magnet shifted but not loose -how to remove in one piece??

By center magnet,do you mean the ring in the middle? Or the magnet inside the outer rim?, how about a pic?

 

[guitman32]

Re: 35amp flywheel center magnet shifted but not loose -how to remove in one piece??

I'm referring to the magnet illustrated here:
http://cdielectronics.com/downloads/troubleshooting guide/OMC Flywheel Trigger Magnet Location.pdf

I'll get a pic in a few hrs but for reference the lower notch on mine is shifted to approx the "27 minute" position.

It is supported by an erratic miss at idle that is not traceable by obvious tests. All my outer magnets are fine. All this down to me using an impact wench on the center nut if I'm being frank after I sheared a flywheel key.

 

[boobie]

Re: 35amp flywheel center magnet shifted but not loose -how to remove in one piece??

You might try a big channel lock pliers on the ctr magnet to loosen it. But very gently. If you break it, it's new flywheel time.

 

[guitman32]

Re: 35amp flywheel center magnet shifted but not loose -how to remove in one piece??

My notches are where the silver dots are in the first pic...the second one is just from another angle...really I dont see any evidence of anything having shifted but they are definitely out of place per the diagram in the link:

 

[Grub54891]

Re: 35amp flywheel center magnet shifted but not loose -how to remove in one piece??

Seen that happen,guy totally rebuilt motor,blew it again. Came to our shop,I rebuilt it,new power pack ext... Could not get it timed perfectly.....removed flywheel and was scratching my head a bit when I spotted the ring was out of kilter a small amount. We replaced the flywheel as not to take a chance of it coming loose from an attempted repar. 6 years later and still running strong!
Grub

 

[boobie]

Re: 35amp flywheel center magnet shifted but not loose -how to remove in one piece??

What seems to be the problem with the mtr??

 

[guitman32]

Re: 35amp flywheel center magnet shifted but not loose -how to remove in one piece??

There is what seems to be a miss/stunble at idle and up to about 2k (only had her on muffs since the problem started so havent taken her past that). Can't get her to idle below 1100 without eventually stalling. There is also some weird blowback out of the middle carb, and what looks to be consistent fouling on the middle port cylinder (blowback is through the carb corresponding to this cyl as well). The blowback isn't hot, and seems to be just uningested fuel mix...almost like a mist firing out the front of the carb at idle.

Spark is strong on every cylinder (using gap tester), but have not yet checked powerpack voltage to the coils.

Swapping power pack leads and coils does not alter the nature of the rough idle of change anything, and besides the coils are just about new. The fouling cylinder move around either.

Compression is 110-120 on each cylinder.

Have run on external tank and pumping ball doesn't really help. I rebuilt the carbs AFTER this issue started and there was no change.

I've had outer magnet issues before and each time i was at my wits end as to why I couldn't get her to idle out smOothly, and each time it was a loose outer magnet. Never had inner magnet issues, but about 2 years ago when I had some outer flywheel magnets come loose I'm pretty sure I inspected the center magnet position (same flywheel and diagram) and it checked out.

 

[boobie]

Re: 35amp flywheel center magnet shifted but not loose -how to remove in one piece??

Have you done a sync & link on it to check idle timing, carb linkage and ect ??

 

[emdsapmgr]

Re: 35amp flywheel center magnet shifted but not loose -how to remove in one piece??

Those vented flywheels do have a pressed-in center timing ring. It is set at the factory-to a very precise tolerance. If the ring moves, it is unrepairable at a dealership. I think only the factory can reset this, and I'm not aware they provide this service. I'd be looking for a replacement flywheel. Keep in mind that OMC made two types of vented flywheels in the 80's and they are not interchangeable. You'll need to get one that is for a specific year (85-88) model. When the 1989's debuted, OMC went to the single power pack and those flywheels use a different center timing ring and won't work on the older models. Be careful, they all look the same.

 

[seahorse5]

Re: 35amp flywheel center magnet shifted but not loose -how to remove in one piece??

You are one year off. The 1988 and later models used the computerized one piece pack with the QuickStart and SLOW features.

 

[guitman32]

Re: 35amp flywheel center magnet shifted but not loose -how to remove in one piece??

Thanks guys...boobie link n sync was ok before the issue, but I haven't yet put a light on #1 to verify idle timing, but I've always found on these motors just using the idle set screw for the throttle lever usually gets you ballpark. I definitely can't get her to idle well anywhere.

Emdsapmgr...thanks for the reply...yep mine is the model with QuickStart slow and the single power pack.

Soooo i think unfortunately the verdict is new flywheel. I really can't the the thing to move while being gentle...would have to tear it up to get it out I think.

 

[guitman32]

Re: 35amp flywheel center magnet shifted but not loose -how to remove in one piece??

Well just went to a yard where they had four of these flywheels lying around...the notches were all in the same place as mine...literally all of them.

At this point I have to think its something else because its not possible that all four flywheels have the same damage as my own?

 

[emdsapmgr]

Re: 35amp flywheel center magnet shifted but not loose -how to remove in one piece??

Thanks for the model year correction. Sometimes it's hard to keep all these model years straight. Agree, it's unlikely that all 4 flywheels have their timing magnets moved... good catch. One other thing, magnets tend to loose some of their magnetism if they are dropped, or hit hard. Possible some of yours did not like being loose and possibly rattling around while the engine was running. If they don't function as designed, low stator output could be a consequence-which can affect running. Might be that you should get the factory magnet glue package (the one with new magnets) and replace just replace the ones which came loose instead of re-using the originals. We had a 150XP that just wouldn't run right. Found the upper main crank bearing had developed flat spots. You could actually hear a little noise out of it at idle. Those flat spots were enough to constantly jar that flywheel to point that low stator voltage was observed. We'd already replaced the stator, so the flywheel was next. That was the ultimate cure for the problem. Interesting that it would idle just fine when the quickstart feature was active-once it shut off, the engine would not idle well.

 

[89renken175]

Re: 35amp flywheel center magnet shifted but not loose -how to remove in one piece??

I had a similar problem with my 89 175 and found that the inner exsaust gasket was leaking water in to #6 cylinder.
She would not idle well at all and would stumble a little when getting on plane and after that would be fine in higher rpm range.
I replaced inner gasket ( which was completely deteriated ) and she idles perfect no misses, coughs or spits.

 

[boobie]

Re: 35amp flywheel center magnet shifted but not loose -how to remove in one piece??

One more thing. The center magnets could be weak causing this prob. Just a thought.

 

[guitman32]

Re: 35amp flywheel center magnet shifted but not loose -how to remove in one piece??

Interesting, so shearing the flywheel key could have cause the center magnet to de-magnetize?

I pulled the middle carb again, and to my surprise the check valve line for the port middle cylinder was snapped clean in half. Reconnected, inspected the reeds (look fine), and no more blow back on the middle carb. Though she still idles the same...will hold at ~1200 rpm with an occasional stutter, pumping the ball just bogs her down, bumping choke doesnt help, so assume its not fuel (again already bypassed the ball and ran her straight to an external tank). Compression remains good. If I drop the idle using the set screw on the throttle lever to about 1k, shell hold until the next "miss/stutter" and then bog calmly. Shell fire right back up...though even in quickstart 5-seconds she doesnt sound the same like she used to.

Still leaning to something ignition related...or...

Yeah im really hoping its not water intrusion. Had water intrusion on my last powerhead, though she still idled well she would bog down on occasion. That and slightly more white smoke from the exhaust. Unfortunately when I tried to remove the bubble back on that one I snapped 3 or 4 bolts (the long ones). I was told to NEVER try that again on these old powerheads, and im partial to agree with them. Might be easier to just find a new powerhead (AGAIN ha!). BUT I will say that on that powerhead you could visually see signs of the water intrusion..not seeing the telltale rusty plugs and white marks on the piston heads, rusty cyliners on this block..

Im basically down to just pulling out all my electrical test equip and run through all the tests and see if I can find anything. Though Im told intermittent issues like this can be hard to identify even with the DVA meter...ill probably work from the ignition coil leads on the power pack and back...maybe also use my timing light a little later in the evening since visually id-ing a misfire will be easier...Ive had powerpacks go on me before, just not like this...

 

[emdsapmgr]

Re: 35amp flywheel center magnet shifted but not loose -how to remove in one piece??

More likely the outside magnets might loose magnetism. The ones which are glued in and make power to run the engine and recharge the battery. If they won't hold magnetism, possible to get low voltage out of the stator.

 

[guitman32]

Re: 35amp flywheel center magnet shifted but not loose -how to remove in one piece??

Test results...

Power pack output FAIL - First measured power pack orange leads using a stephens load adapter...values were between 135-150v highest on all cylinders. FAIL (manual calls for 175v min), although there is spark on all cyl that jump a 1/2" gap, spark just seems very erratic (using the 8-cyl spark tester, so I can see all spark at the same time). Seems like a randon miss on two of the cylinders to my eyes.

Since the power pack failed on all cylinders, went to the beginning of the process...

Stator PASS - both output and resistance tests passed (getting at least 280v output on each side)

Timer base FAIL - failed on both resistance and output tests. For the resistance test, rather than quote specific values (since Ive gotten different readings on different meters), suffice it to say I saw a varance on at lease two of the leads on the port side (360 vs 750 ohms), and all values were consistent on starboard side. Output was weird, I got zero readable output on any of the leads. Now mind you im using a craftsman multimeter and a homemade DVA adapter with a .3v drop. This means that on the one test where youre looking for .2 v, I wont see anything. Although I also saw no output on the test where it calls for at least 1.2v output either


So I would lean to replacing the timer base before the power pack, but in the CDI literature a weak trigger magnet is even specifically called out as a possible cause. Could a weak timer base output cause a low power pack output?