OK! Now that my FL350r is rebuilt and ready for a go, its back on the trail of figuring out this Pilot ignition problem, where on the trailer I only see about 6200 rpm peak while in N, and on the trail its like a hard rev limitation at 7200 as indicated on my tiny tach.
So, Pilot Bird let me borrow another
CDI (Capacitor Discharge Ignition). It didn't seem to make any difference on the trailer and so I bought a stator from a place called regulatorrectifier.com. It came with a pulse/trigger coil.
The new pulse/trigger coil is measuring 65k ohms and so I think its dead out of the box :( and I've emailed Regulatorrectifier.com. By comparison, my stock pulse/trigger coil is measuring 360 ohms which is correct.... but the old stator as a whole is still a suspect.
So tonight I decided to run some peak/hold AC voltage checks on the stator with using the Engine's pull start. I got ~5vAC on each of the 3(4) Yellow wires coming from the stator - 3 go to the rectifier, and the 4th which I believe is just T-ed into one of the other three wires goes to the CDI (Capacitor Discharge Ignition). The trigger coil is measuring about .4vAC
Pullstart test referencing ground:
Stator yellow wires: ~5vAC
Stator trigger/pulse coil: ~0.4vAC
So this made me wonder about something. The FL350 stator is quite different - It has a lighting coil, charging coil, and a trigger. FL350 charging coil can reach 70vAC. The FL400 stator/CDI (Capacitor Discharge Ignition)/regulator setup is quite different. Instead of a charging coil, its using the lighting coil - aka alternator coil - for both the charge AND the lighting hence why the voltage is so low at 5vAC compared to the FL350. Next I thought to check the FL400
wiring diagram to see how the CDI (Capacitor Discharge Ignition) connects to the alternator, and the battery - and sure enough the 400 CDI (Capacitor Discharge Ignition) gets a direct reference to +12vDC from the battery (Through the ignition and the off/run/off switch). Because of this, the CDI (Capacitor Discharge Ignition)'s sensory of +12vDC is also carrying whatever the alternator is being converted to at the rectifier. [edit] It is possible this type of CDI (Capacitor Discharge Ignition) is depending on direct +12vDC from the battery in order to charge for ignition spark. If any of the ignition/switches are slightly dirty then a loss of amperage/voltage through this wiring could prevent the CDI (Capacitor Discharge Ignition) from charging. Not sure if the CDI (Capacitor Discharge Ignition) charges through the yellow wire or through +12vDC as it could actually be from either. I know not enough about the FL400 CDI (Capacitor Discharge Ignition) to be sure.
This got me thinking. I've seen small vehicle rectifiers fail in the past... unfortunately its not very straight forward testing the rectifiers directly. Instead, you can measure what a
rectifier can do rather than what it's numbers are with a direct probe. What I mean is - measure it's output in action. It should be putting out about 12 to 15 vDC at the battery, and NO AC. Batteries tend to not like AC - in fact they struggle with AC voltage which a battery will actually convert to DC. If a battery sees too much AC voltage for too long, the battery wills tart to over-heat and fail, but until then a battery does a strong job of being the 'rock' in a DC voltage system - at keeping DC going and AC at bay.
Three ways one can rule-out the rectifier:
1 - unhook it at both plugs. This will disconnect the alternator from the whole system; except the CDI (Capacitor Discharge Ignition) will still get fed one of the legs for it's charge. Will the
Engine continue to run? I don't know for sure, but I think it should while the battery still supplies +12vDC. I'm going to test what the maximum RPM is while the rectifier is disconnected to see if its any different, ad if not...
2 - unhook the battery at the negative terminal. Pull start the Engine. This is a bit more dangerous and detrimental to the electronics. If the rectifier happens to be bad, the possibility of it passing AC voltage across it's output instead of DC could mean some fried parts in the test. I recommend getting the meter probes onto ground and +12v and get ready to check both the DC AND AC output at the disconnected battery terminals. There should be no significant AC across the battery terminals. Probably 0.1vAC would be ok, but anything over that would cause me to question.
3. Swap the rectifier with another unit. No-can-do. I don't have a spare.
At the end of the day, my final thought is if the rectifier has gone south, then the voltage supplied to the CDI (Capacitor Discharge Ignition) which referencing +12vDC could be interfering with what the CDI (Capacitor Discharge Ignition) needs to do - IE produce output to the coil at any given non-limited RPM.
If I find the rectifier tests didn't help or conclude anything at all, then I've got to have a bad stator.
But, one more test. Now that I have a nice running FL350r - I'm going to try swapping-in the 350's ignition coil into the pilot as they look to be very similar parts.