Reluctor rings

**bigbluechevy454** · 12-14-2017, 09:36 PM

Someone school me one reluctor rings. What’s different about a omc vs a mercury vs Yamaha? Just wanting to learn. So I could possibly do some cross breeding lol thanks

**Instigator** · 12-15-2017, 06:33 AM

Not sure on comparison but I know if they're not in correct location in relation to flywheel, they will run horrible if at all.

**bigbluechevy454** · 12-15-2017, 07:22 AM

I think it’s just a strip of metal with a notch to break the magnetic field but I’m not sure that’s a guess.

**FORBESAUTO** · 12-15-2017, 08:53 AM

Not sure on the different versions between motors. But the teeth is what the module uses to determine crank degrees. There will be one oddball one, usually just a missing tooth that will correspond to TDC of cylinder 1. This is what it uses to get firing order started and figure ignition timing. It can also monitor the speed each segment passes by the sensor to determine a misfire and which cylinder missed or change in how well the cylinder hit. Not sure if Outboard's get this envolved or not. If you have continuous segments all the way around so it can monitor the full 360 degrees, then it's very possible. If only a few segments it's just getting certain points of degrees for certain cylinders. So, yes they have to be positioned correctly being that's how it determines ignition and in some cases fuel timing. Hope this is helpful, this is a generic explanation of how it it works, but I'm not familiar with the different uses on different Outboard's.

**H2OPERF** · 12-15-2017, 09:36 AM

There are Many different teeth combinations, aftermarket ecu common teeth counts are 24-2,36-1,58-2 with even teeth spacing... The fitch/etec has oddball spacing and sloppy lugs are cast into the flywheel. I guess when the mfgs are programming the the ecu dedicated for an application they put the teeth any place they want so the crank position can be known early. The more teeth the finer the fuel/timing events can be but at a cost to max rpm of the application due to amount of teeth passing the hall sensor, which gets pretty high at 10k. The hall effect sensors are fast but they have limits the etec one looks similar to the common honeywell gt101dc, which is fast 25khz, but the mfg told me tooth size and spacing will have some effect on the ability to hold a clean sine wave. I made one from a sprocket since i was unable to fine a 24 tooth of the right size, the one on the right is a 58-2. the sensors have size data on the spec sheets most want about a .200 tooth at .050 gap. As far as swapping stuff around brand to brand its all about the ecu programming so i doubt its possible..Dave

**bigbluechevy454** · 12-15-2017, 10:10 AM

One would have to wonder why they are glued On flywheel rather than casted into the flywheel

**H2OPERF** · 12-15-2017, 10:35 AM

Ahh your just talking about the trigger ring for the ignition only sorry miss understood. Dave

**gfinch** · 12-15-2017, 01:08 PM

I do know a slight imperfection in a trigger/tone/reluctor ring(same thing different app)will wreak havoc in signal wave form output thus causing bad running even if it starts. More than one car towed in as a no start or barely running condition after someone else was working on it. Just dent one of those teeth and find out. Or leave the crank pulley bolt loose, a nice intermittent.

**H2OPERF** · 12-15-2017, 02:38 PM

Agreed on that one.. seen it too on a junkyard motor that wouldn't start, but i think hes talking about old school flywheel hub trigger rings.. just magnets in the hub and sensor coils signaling the ignition packs to fire. Many diff configurations on that too, most people switch the entire ignition system like yami to omc.. Dave