RC51 No Start/ No Spark

[xrocket21]

Hahaa! I cursed myself! Sorry to hear. That sucks. Next up. Coils, cam position sensor, crank position sensor.

Thanks for the help man, I appreciate it.

[Paul_E_D]

Back to your original day. Bike died after 100 mile ride sounds to me like the battery was not charging. When you say battery is good, what does that mean exactly? Was it at 13+ volts right after it died? Or did you have to put it on a charger?

Symptoms are similar to my triumph when the stator AND cam position sensor both failed due to faulty regulator/rectifier. crank no spark is the classic symptom. Bike dying after 100 miles points to no charging happening.

[xrocket21]

Not a battery issue. Now, and that day it will crank and crank with no fire. The dash lights never dimmed or flickers or anything to indicate it was a low battery situation. I actually cranked it over many many times on the side of the road to get it to start. Not a single cough.

Im leaning toward a chaffed/pinched wire somewhere, but I havent found it yet.

30k+ miles, so it could easily be a sensor or something as well.

[Paul_E_D]

Cam sensor dying wouldn't cause the bike to quit on the road. Crank sensor would. No engine light? A pinched wire would likely cause other electrical issues. Not as likely in my book. (now that I say that, you will find a pinched wire!)

[SwiftTone]

Does it crank?

Sent from my SAMSUNG-SM-N920A using Tapatalk

[xrocket21]

I replaced both coils probably 7 years ago, a plug wire got pinched under the tank, electrifying the tank, hitting my pants zipper, shocking my crotch. So the coils are only 10k miles old. No engine light at all. Turn the key, the dash lights up, fuel pump cycles, and the bike turns over like a champ. zero spark. ( i have the plugs out, laying on the frame to visually look for spark.

I have the factory honda manual and it lists what to check next, so I guess thats what Ill do.

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Does it crank?

Sent from my SAMSUNG-SM-N920A using Tapatalk

yeah, turns over no problem

[number9]

Can you try bump-starting it?

[xrocket21]

Can you try bump-starting it?

With no spark and plenty of battery power and it turns over just fine?

I don't think bump starting it would make any difference.

[number9]

With no spark and plenty of battery power and it turns over just fine?

I don't think bump starting it would make any difference.

Yeah, it was a bit of a stab in the dark.

Do you have a service manual? The service manual for my VFR is very comprehensive when it comes to troubleshooting, I highly recommend it.

[xrocket21]

Yes, I have the honda service manual and Im working through it.

[jeantarrou]

If you think it's the CDI (a relatively common failure item) I have a good one that you could borrow.

[number9]

If you think it's the CDI (a relatively common failure item) I have a good one that you could borrow.

Does the RC51 have one CDI unit or two (i.e. one per cylinder)?

[Jim]

if the fuel pump works, i would have eliminated the PC3 as suspect.

how about the tip over sensor, as it's been mentioned already on here.
the fuel line isnt kinked right?

[xrocket21]

Does the RC51 have one CDI unit or two (i.e. one per cylinder)?

individual coils per cyl

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if the fuel pump works, i would have eliminated the PC3 as suspect.

how about the tip over sensor, as it's been mentioned already on here.
the fuel line isnt kinked right?

fuel pump wont cycle if the tip over sensor is tipped.

kinked fuel line? The issue is no spark.

[number9]

individual coils per cyl

And neither spark plug is firing? In that case, swapping CDI modules won't get you anywhere.

Does the kill switch on the RC51 kill fuel and spark or just spark? On the VFR, it kills both, so if the fuel pump is cycling then your kill switch is fine.

[jeantarrou]

And neither spark plug is firing? In that case, swapping CDI modules won't get you anywhere.

Can you explain this? If the CDI is bad (there's only one on the whole bike) one plug would fire and the other wouldn't?

Does the kill switch on the RC51 kill fuel and spark or just spark? On the VFR, it kills both, so if the fuel pump is cycling then your kill switch is fine.

Kills spark and the fuel pump won't prime.

[ZX-12R]

I know you said the FI light isn't on but have you tried seeing if the ECU will flash a code anyway? There is a green 2 pole connector near the ECU that you jumper out with the ignition off. When you turn the ignition on, any codes that are present will flash patterns in the FI light.

[xrocket21]

I know you said the FI light isn't on but have you tried seeing if the ECU will flash a code anyway? There is a green 2 pole connector near the ECU that you jumper out with the ignition off. When you turn the ignition on, any codes that are present will flash patterns in the FI light.

I did not think to try that!

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And neither spark plug is firing? In that case, swapping CDI modules won't get you anywhere.

Does the kill switch on the RC51 kill fuel and spark or just spark? On the VFR, it kills both, so if the fuel pump is cycling then your kill switch is fine.

neither plug fires. The killswitch cycles the fuel pump, not sure about spark.

[xrocket21]

Well, I finally had some time to work on the bike some more.

The yellow wire into the ECU, which is the ignition pulse, is pretty pinched, but seems to pass current fine, ill have to fix it, but I dont think it is the problem.

When trying to start, I got 0.3VDC at the ecu, at the first plug, and at the plug closest to the coil. Manual says 0.7VDC is the minimum.

In hindsight, I ran this test without the plugs attached, but I don't think that would affect it, but I'm not sure.

I was also surprised to find a little oil behind the side cover when I went to remove the ignition impulse generator.



I hope it is just the impulse gen and I can get this fucker back on the road

[TheIglu]

I've had a situation where the pulse generators would work until they got hot, then she'd die. No spark.

[xrocket21]

Its only $50, so Ill try replacing it

[TheIglu]

I'd be sure it's not the battery first..... I know you said it cranks over fine, but I've seen plenty of instances on FI bikes where it cranks fine, but no spark due to weak battery.

Toss a jumper cable on from your car battery (without it running of course) and see if it changes at all with plenty of extra headroom on the battery.

[xrocket21]

I have had a battery charger on it off and on while I have been messing with it. it is not the battery. And that wouldnt make sense pertaining to the day it died, 45 min into an hour ride and I cranked the shit out of it on the side of the road when it died. It is a strong, newish battery. It is not the battery, the coils arent firing at all.

[xrocket21]

ignition impulse generator didnt fix it

guess Ill put it back together and have someone else fix it :/

[hawk]

reg/ rectifier, that is what I think.