Flywheel magnets

[groundloop]

On my '90 Johnson 200 I run out of adjustment just shy of getting the idle timing where it needs to be. (The engine wants to be around 4 degrees after TDC at idle, closest I can get it is around 5 degrees after). I was able to give it that last little bit of timing by turning in the idle stop screw and rotating the cam roller away from the timing cam (so the carbs are closed at idle the way they're supposed to be). But now the pointer is no longer pointing to the roller as called for in the link-n-sync procedure - this has to effect the timing curve a bit. It runs good like this, but I'd rather be able to have it adjusted the way it's supposed to be.

I'm wondering if the flywheel magnets aren't off from where they're supposed to be, that's all I can think of that makes sense. I didn't think to check this the last time I had the flywheel off (though I did pull hard on all the magnets and nothing's loose). So I'm wondering - even if I find that the magnets are out of position how do I adjust them?

[perfmarine1]

Did you first check and make sure timing pointer is at TDC using a piston stop? Flywheel magnets are not adjustable, they are epoxyed on if they are loose you must epoxy them back on.BRP sells a kit to do that w/directions to do so. Thats outer mags only,if iner mags move it will not run for crap. The gap between outer mags should be equal all the way around.

[racer]

Ctr hub controls timing not the outer magnets and like perfmarine1 said check the pointer first.

[groundloop]

Yes, I've adjusted the timing pointer. Regardless of that I run out of adjustment (when link-n-sync is done per OMC factory manual) just before I get enough idle speed to keep it running in gear. And like I said, once I'm able to get it to 4 degress after TDC it runs great, but I know this isn't the proper way to have it set up.

I was hoping someone could tell me to heat the flywheel to a certain temperature to loosen the epoxy and pop the magnets off or something like that. Guess I'll pull the flywheel to check, and if my hunch is correct start looking for another flywheel on ebay.


thanks

[seahorse]

If you are sure that the carbs, reeds, and recirculation system are clean, adjusted, and functioning correctly and that the thermostats are warming up each cylinder head correctly, then you might perform a leak-down test on each cylinder and compare that with the results of your compression test for each one.

[perfmarine1]

Remember you must start from the begining and work through all the steps in order with throttle cable removed accept for max timing and idle timing. these 2 you must be in the water or test tank with proper test wheel or proper prop not on flusher.

After you adj idle timing it will change when you adj idle speed since adj timing is how you adj idle speed and that will vary depending on prop size and motor condition that is normal a motor with a big pitch prop will need more idle speed than a motor with a low pitch prop.

[perfmarine1]

Remember outer magnets just supply the voltage to ign system they are the ones that come lose,the iner sm magnets controll the timing and it would be very rare for them to move. If you suspect them index the flywheel and check each cyl with timing light.

[groundloop]

Yeah, I should have specified I was asking about the inner magnets. I pulled the flywheel and it looks like they're very close to a diagram I found showing where they're supposed to be. I guess I'm grasping at straws, and as it turns out I've got egg on my face again after saying that this engine was running ok. After installing Chris Carson reeds it idles great in a tank which it would never do before, and I really thought that was the last of my problems. At the lake today as soon as I come off idle it just fell flat on it's face, I was only able to keep it running a couple of times by going real hard to about 3/4 throttle or thereabouts.

The thing is, I've replaced nearly everything on this engine (and not just because I've been throwing money at it, each time I replaced something it was because a part tested bad). Anyway, to my next question.....



I've got '96 carbs on it (my engine's a '90), and noticed that there are different part numbers listed for the throttle cams for the '90 and '96 engines. Could the fact that I'm using a '90 throttle cam with '96 carbs be causing this?

Also, seahorse mentioned a leakdown test. I agree that that's a good idea (compression is around 80 - 85 on all 6 cylinders, I understand that's a bit low for this engine). I'll have to cobble up a leakdown tester in the next few days. I used to look over the shoulder of an airplane mechanic I knew when he was doing leakdown tests on airplane engines so I'm somewhat familiar with that. However, does someone have a link on how to properly perform and interpret leakdown tests on an outboard?

thanks

[seahorse]

Now you tell us that there are different carbs than what the engine came with.

That can make a big difference as a '96 engine block is a different design than a '90 cylinder block. You need those carb adjustment screws at least 6 turns open to make a '96 engine idle well, some motors need 7 turns. You may also have to play around with the midrange airbleed jets to make it run well.

Still do the leakdown test to find out for sure what the internal health of the motor is.

[groundloop]

That can make a big difference as a '96 engine block is a different design than a '90 cylinder block.... You may also have to play around with the midrange airbleed jets to make it run well.



Holy Crap Batman !!! We might be onto something here!

Thanks seahorse. (I've got more questions but am going to start a new thread on this to make the title match the topic.)

[doogall]

Yeah, I should have specified I was asking about the inner magnets. I pulled the flywheel and it looks like they're very close to a diagram I found showing where they're supposed to be. I guess I'm grasping at straws, and as it turns out I've got egg on my face again after saying that this engine was running ok. After installing Chris Carson reeds it idles great in a tank which it would never do before, and I really thought that was the last of my problems. At the lake today as soon as I come off idle it just fell flat on it's face, I was only able to keep it running a couple of times by going real hard to about 3/4 throttle or thereabouts.


This might help to decide about the magnets. Cheers Craig
236969

[baddjonny]

Go to the CDI ignition website they have a diagram showing the position of the inner ignition magnets in relation to the flywheel keyslot.if not I'll see if I can email the diagram as my diagram is in adobe acrobat and I don't know how to send it as a attachment here.

JON B