1990 Force 90 Ignition Not Firing On All Cylinders

[Derrick Fronckowiak]

I own a 1990 Force 90 and have been trouble shooting the ignition system. It was running but WAS firing only on #2 and # 3 cylinders, but not on #1 (I verified with a timing light). I read out resistance on the trigger, the stator and the coils and all read within specs/limits, no opens, no shorts. Also got DVA test leads and checked DVA voltage at the stator, all within limits. At that point I was done monkeying with it for the winter, I winterized and let it be. A few weeks ago I was getting things ready to go for fishing season. I went to start up and had NO cylinders firing. I pulled off the flywheel to discover that the flywheel's center trigger magnets and layered plates were damaged (due to physical contact). I got another flywheel and installed it. Now it's firing on cylinders #1 and #2, but not on #3. What the.....? Now I've got sparks, but it seems the original problem "moved" from Cylinder #1 not firing to #3 not firing. I'm frustrated and baffled and really want to get this fixed, but don't want to randomly change ignition components. Anybody got any ideas about anything else I could/should check?

 

[jerryjerry05]

Try changing the coils around and see if the spark follows the switch?
Same results? Swap the packs. Compression test?
​Lots of times the trigger leads break under the shrink wrap on the buss bar.
I had an intermittent miss on a cold motor. After it warmed up it was great.
One time I went out and had a miss that wouldn't go away.
I touched the 1st. trigger lead and it pulled right out of the connector.
Replaced the connector and haven't had a problem.

 

[gm280]

Derrick, when you have three cylinders, you have access to three sets of everything to swap around. But mark the good ones so you don't get everything mixed up in your swapping. And do the swaps in a systematic fashion. If swapping doesn't offer any solution, then you have whatever feeds the three coils as a problem. JMHO!

 

[Derrick Fronckowiak]

[FONT=&quot]jerryjerry05 and gm280,
Thank you both for the quick (and thought provoking) replies. I have in the past swapped around coils (back when I originally had just the #1 cylinder not firing), but the problem stayed with the #1 cylinder (OK so it "seemed" the coils were all good). I've also swapped the packs around in the past since pack #1 feeds cylinder #1 and #2 and pack #2 feeds cylinder #3 (the forth set of leads on pack #2 are unused unless you've got a 4-cylinder engine like a 120). Having said all of that, I'm going to try it all again since I did find my flywheel jacked up. I've changed a component (my flywheel) but still assuming all my past component swapping is still valid. So it seems logical to start swapping again from the start. Coil swapping is real easy (and quick) to do. If that doesn't reveal anything, I'll swap the packs again (I'll mark everything as gm280 suggested). Also, what gerrygerry05 mentioned about the trigger leads is VERY VALID!! I've reswedged/soldered a few that I thought were questionable (even though there was good continuity and resistance readings at the time). I can't believe they make those leads and terminals small and seemingly fragile. Soooo, when in doubt...swap them out! If all of those checks don't reveal anything, I'm wondering about the stator or rectifier (troubleshooting steps in the Seloc manual say to disconnect the two leads from the stator to the rectifier and if the cylinder fires, replace the rectifier). Will let you all know how it all turns out. Thanks again for your expertise!!![/FONT]

 

[jerryjerry05]

outboard ignition dot com has test procedures for each component.
​Seloc is ok but leaves a lot to be desired.

 

[Derrick Fronckowiak]

No Title

Well, it seems that now I've lost ignition on all cylinders. I pulled off everything to check (again) and I noticed that inside the trigger inner circumference the areas that mark where the three trigger points are it looks like some of the metallic covered area has "wore" away. Check out these picks. Resistance measurements are good for all three trigger coil circuits. Can this wore away metallic material at each of the trigger points affect the triggers ability to send the signal to the packs? Seems to be good trigger circuit integrity, but this looks more like physical degradation. Thoughts anyone?

 

[jerryjerry05]

Probably not the problem.
It would have to be reallllly scored to hurt anything.
Get the test procedures from Outboard Ignition.
Test all the components.

Did you happen to hook up the battery leads backwards?
Is the magnet in the flywheel still glued in place?

 

[pnwboat]

Can you post a picture of the flywheel, both sides?

 

[Derrick Fronckowiak]

jerryjerry05 and pnwboat, thanks for the quick reply. I did follow the test procedures from outboardignition.com. Didn't really reveal anything. I never hooked up the battery leads backwards. Magnet on the flywheel is in great shape, I know this because I replaced the flywheel because my original one was damaged and corroded. The replacement one is in much better shape, has no corrosion (used in fresh water) and all magnets are firmly attached. I wanted to eliminate that as a possibility, so that's why I replaced it. Before I replaced it I was firing on cylinders 2 and 3 only, then it stopped firing on all cylinders the next time I tried to start it. After I replaced the fly wheel it started firing on cylinders 1 and 2 only and then stopped firing on all cylinders the next time I tried to start it. All resistances read good (coils, stator, trigger), but I couldn't check DVA voltage (I do have a peak voltage adapter) because now it's not running. Also, while it was running I disconnected both kill wires to ensure my harness and ignition switch weren't the problem, also isolated the rectifier (per the troubleshooting in outboardignition.com), still no joy. All leads appear to have good continuity (I was really hoping to find something open or shorted, maybe a loose terminal). Also, I don't think you can really check the packs unless you guys know something.

 

[pnwboat]

Just want to confirm that you have the Prestolite Ignition system with 2 Sky Blue CD Modules and 3 Sky Blue coils. The flywheel should have a single strip stator magnet that runs the entire inner circumference of the flywheel like pictured below.

 

[tommarvin]

This is a broken or breaking wire in a connector, give every wire a tug and a twist going into a connector.
Then check every inch of wire on the motors ignition system.
You can test CDI packs ,I don't have a clue how.
Your flywheel looks better than ours.
YOU HAVE A GROUND WIRE LOOSE OR breaking or BROKEN ON THE COIL(S) or cdi packs, or someplace ?
This is by far the most complicated ignition question problem I have seen on here, Please tell us what it was so I can learn something!!!

 

[Derrick Fronckowiak]

pnwboat and tommarvin, thank you both for the reply. Yes, my flywheel looks just like the one in your picture (but with less corrosion). Outer magnet is fully intact and two inner magnets and stacked plates are in great shape too. As far as a broken or loose wire, I think that seems like a definite possibility. Yesterday I pulled off the flywheel, stator, trigger, the packs and coils. I'm going to tear into everything and I'm replacing the ground wire that grounds all the packs and coils (it just looks questionable). I think I'll redo all of the terminals too (the ones coming off of the trigger leads are soooooo small and frail looking). I'm thinking about components being bad, but before I start spending money I want to be sure (maybe the fact that I'm a cheapskate has something to do with it too). Also, quick question, does anyone know how far down the fly wheel gets pressed down on the end of the crankshaft? Should it be pressed all the way down to where the shoulder (below the threads) is flush with the fly wheel surface? Just want to be sure I had it pressed down all the way, if it's not down all the way, maybe the magnets in the fly wheel aren't lined up properly with the trigger or stator coils. I'm only guessing at this point. Thoughts?

 

[Derrick Fronckowiak]

pnwboat, one other thing I forgot to address, yes, all my components are Presolite ignition components, the packs, the coils, trigger and stator. I have no CDI or other aftermarket components.

 

[Mohawkmtrs]

Derrick...Flywheel nut should be torqued. Specs are:

Ser # OE138599 and below 90 ft.- lbs.
Ser # OE138600 and above 125 ft.- lbs.

 

[Derrick Fronckowiak]

That's some serious torque, and keeping the flywheel from rotating while trying to torque it ain't no joke either. I'm just concerned that the taper on the crankshaft and the taper on the inside of the flywheel aren't mating up right and the flywheel isn't going down all the way. I'll polish them both up when I'm putting everything back together to make sure there are no burrs, nicks or anything that would impede the flywheel from completely seating all the way on the crankshaft. Thanks for the torque data for the crankshaft nut. Will share what becomes of all of this..

 

[pnwboat]

Try disconnecting the white wires from the CD Modules at the terminal block and tape them up. These are the ignition Kill wires. They get grounded when you turn the ignition switch to the "OFF" position, or disconnect the Kill Switch lanyard. If spark returns with these wires disconnected, then you have an issue with your Kill Switch, ignition switch, or wiring between the CD Modules and the ignition/Kill switch.

If by chance the motor starts with these wires disconnected, you can choke the motor to shut it off. With these wires disconnected, the ignition Kill circuit is disabled and turning the ignition switch to the Off position does nothing not stop the motor.

 

[Derrick Fronckowiak]

Gentlemen,
This is the first time I've chimed in since I heard of Frank's passing. I haven't been on the forum long, but he was the very first to answer my questions when I first started using this forum. I will miss his kindness and willingness to offer his sage advise and guidance.

 

[Derrick Fronckowiak]

Now that I've returned in a somewhat somber mood I share what has com to pass since my last posting regarding my ignition issue. My 90 HP was firing on Cyl #2 and #3, but not at all on #1. Resistance and DVA voltage read within limits on all trigger circuits and all stator circuits. I swapped the packs and then #1 and #2 were firing, but not #3 so I thought, OK the problem seemed to move from #1 to #3 following the swapping of the packs, so logically I figured I have a bad pack. Well I got another pack and swapped it with the pack that was not allowing #3 cyl to fire. Now I get #1 and #3 firing, but not #2. (OBTW I verify firing by checking with a timing light). It seems that no matter what I swap out I can never get more than 2 cylinders to fire at any given time. Swapping packs simply makes the dead (non firing) ignition circuit move to another cylinder. Could my stator be bad/weak and not be able to provide the juice to fire all three cylinders (despite the fact that I get good resistance and DVA voltage when I read out the stator - stator leads 1 and 2 are 686 ohms and 258 volts, stator leads 3 and 4 is 689 ohms and 255 volts)? I also checked the kill circuit and the rectifier and they both check good. This is driving me nuts!!! Ideas anyone?

 

[tommarvin]

1. It just has to be a WIRE that's grounded out, or a ground wire is loose, off or broken in a connector, give all wires a hard pull going into all connectors. ,

 

[Derrick Fronckowiak]

Tommarvin, I hope you are right. I'll check all connections once again. But the way this thing hops around from cylinder to cylinder just doesn't make sense. I'll recheck all ground connections. Both packs each have a ground wire that grounds to the ignition frame, then the frame has a ground wire that grounds to the engine block. As far as actual electrical connectors (male-female plug-in type) them selves go, the only ones that exist (on my engine model) are the single lead connectors that snap together from the packs to the P-leads of each coil. All the rest are spade or those fork type connectors that attach to the ignition terminal block on the ignition frame and are held in place with a screw. I'll recheck for chaffing in wires and weak connections on the terminals (again). Thanks for your guidance, we'll see how it turns out.