What just happened to this Dyna-S? pics too!

[Carter Turk]

I just did my second trackday of the year @ The Ridge Motorsports Park on the 5th.
Super hot day near 100 degrees, bike ran great (83 Katana 1150-1229-mechanical advance from 1100), even started every time I tried, but the second to last session, with a lap or two remaining, something happened...
Too hot to diagnose, since electrical stuff baffles me, I wouldn't figure it out before the last session anyway, so I had a moment tonight to investigate.

Battery 12.86 with key on headlight fuse pulled out. That's it for electrical numbers.
Checked sparkplugs next- looked a bit lean-not much color- bike cut out at the end of front straight under heavy single piston braking.
I puttered on what felt like 1-2 cylinders another 15 turns with my hand up off the track line back to the pits. Made it.

I expected fouled plugs, and also noticed a carb cap popped off #3 carb (90 gsxr-11 36mm)- bike has been blowing off carb boots (carb to engine) lately, mostly 3-4, but 1-2 recently.
Tried grounding plugs from each coil-1 no spark, 3 had spark, so I swapped coils had another spare Dyna 3ohm. Still no spark on 1.

Next checked the Dyna-S. Upon removing the cover, I noticed a lot of dust-metal dust.
I could be wrong but I recall the Dyna-S rotor to be black when new and the magnet hard to distinguish, basically flush with the outside diameter of the rotor.
My coil 1-4 could be shot-done, but these picture are suspect to what may have happened. Looks like the magnet unseated and was pushed forward from centrifical force or something.

I think the last picture is 1-4 trigger on the Dyna-S. Also the rotor will not come off the mechanical advance with it fully advanced.
Your take on the matter greatly appreciated if any.

 

[SVSooke]

Having installed a Dyna S not long ago you are right the magnet is flush. That's an interesting failure I doubt slow me will get.

 

[GSCafe]

Running Dyna for decades. You do it right it stays done. Talk to Dyna. Dust and crap is okay, it doesn't affect magnets. Stuff misaligning is not okay.

 

[Carter Turk]

Running Dyna for decades. You do it right it stays done. Talk to Dyna. Dust and crap is okay, it doesn't affect magnets. Stuff misaligning is not okay.

I've already had one brand new that came with a faulty 1-4 trigger.

They replaced free of charge after inspecting it.

I've been using Dyna products for 20 years too.

The dust was just a reason to inspect further + the rotor is fused to the advance mechanism.

They are a great company to work with, and I will call them and send in parts for inspection.

I believe I mounted it correctly 3 years ago.

Did you notice in the pictures the magnet wore through the pickups?

 

[geol]

The rotor has obviously been grinding away against the pickup coils. The rotor is painted black with the magnet slightly indented on a new one. One of the pickup coils looks like it is the culprit for the rub but how that could be is beyond me as there isn't any adjustment as far as moving it nearer or farther away from the rotor. It will move a little laterally to the rotor if you loosen the two little set screws that retain the pickup coil to the backing plate.

The last few times I have installed a Dyna S, I have noticed they don't seem to pay much attention to placement of the pickup coils... in other words 1/4 is not really 180 degrees away from 2/3. When you first time the thing, you do 1/4 usually and then loosen the little allen screws holding the 2/3 pickup coil and when timing, you have to move the pickup coil to the edge of its adjustment and since the slots are open ended where the screws go through, it might be possible that the pickup coil moved off one of the mounting screws and one end dropped in and contacted the rotor.

When I find this type thing happening , I offset the 1/4 pickup coil from its initial placement so I can located the 2/3 coil 180 degrees across from it and still not be near the edge of its adjustment location. On my last Dyna S install on a GS1000, I used a dremel with cut off and make a mark on the 2/3 F location and 4500 advance location so I can time the thing more closely on the 2/3 side.

 

[Guest]

One thing you need to do is lube the advance mechanism regularly, regardless if it's stock or with the Dyna rotor.

I hadn't done mine for a while and last service discovered it was not good... rust coloured dust all over the shop and did not advance smoothly at all. Added some 3 in 1 and now smooth as silk... I usually use engine oil but had the 3 in 1 handy at the time.

However, as others have said, that magnet in the rotor has definitely been dislodged. It could be the cause if it came out under centrifugal force, or if it was rubbing then it could've caused it to dislodge.

 

[Guest]

This is a faulty rotor
That's it
Took out the coils

 

[Carter Turk]

I talked and sent the rotor to Larry today at Dynatek in Las Vegas this along with two coils, just for their inspection.

He was more than willing to help, suggesting which way to send etc, got a RA #. I didn't want to try and force the rotor off

the advance mechanism, I popped the e-clip off one of the arms, no movement w/o force, so I left it. Sent it down in a small flat rate box

with 2 Dyna-3ohm coils ($6.80). He said he hadn't seen a magnet pop free of the epoxy/powdercoat in a long long while.

Would you folks concur that this may have caused loss of power on 1 or more cylinders? I tried two coils, not sure if the 2nd one was good or not

and only checked one plug per side figuring if one wasn't firing 4 wouldn't be either.

 

[Carter Turk]

Update if anyone cares, Dyna inspected the Dyna-S, said the epoxy failed which is rare (seen a few), but the fact it's 10 years old, didn't warrant a free replacement.

I was hoping for that, but not expecting it.

Both coils I sent in checked out fine, so I guess the rotor scraping through the pickups caused 1-4 to shut down, but didn't damage the coil.

2-3 trigger was still apparently firing, even though it had partially scraped through.

So I'm out hundred bucks.

On a positive note, the failure allowed me to notice a cracked header on #2 cylinder (14'' down),

might explain the excessive crackling/popping on deceleration that presented itself on 1st trackday on the 23rd of May.

I could pull off the Yoshi on my wife's bike in a pinch, but the Kerker has a franken yoshi/V&H/Kerker baffle/can with a bigger outlet.

 

[Carter Turk]

Installed the new Dyna-S last night. Static timed it-I think.
Light went on when fully advanced-off when released-lined up with the timing plate.
Didn't want to fuss with the pickups because I assumed I'd make things worse and it would at least start w/o touching them.
The modern Dyna-S is much trimmer than the one I replaced-all tiny and sleek.
Got the #2 header crack fixed and put some NGK caps on the plugs-the others pulled off when removing the coil wires with the fat sparkplug adapter.
Took it for ride tonight, all seems well, firing all four cylinders again-woohoo!

 

[Guest]

Thanks for the updates, always nice to read a thread thru to its conclusion.