RC51 No Start/ No Spark

[number9]

Bad R/R shouldn't affect it starting at all. Yeah, you'll run the battery flat once the bike is actually running, but that's a different issue.

[xrocket21]

trying swapping ECU's with a friend tonight



Why didnt I get this fixed over the winter?

[Fitron]

After reading through this whole thread for reference, I realized that there was some confusion over CDI units. There is ever only ONE per engine, no matter how many cylinders. The CDI unit is NOT the ignition coil, as it seems some would think. If you haven't tried swapping CDI's, I'd bet that is your problem. A quick check of the part online shows that it's about $416 from the dealer, and is called a "Converter Unit" by Honda. It's on the "Wire Harness (R.R.)" page of the microfiche.
It looks like this:

http://img.photobucket.com/albums/v6...psk7pwtalv.jpg

-Gary

[Kurlon]

After reading through this whole thread for reference, I realized that there was some confusion over CDI units. There is ever only ONE per engine, no matter how many cylinders.

-Gary

Actually, this is not 100% accurate. Look at the Honda VF750/VF1100 series. Two 'igniter boxes' per motor. One for the forward bank, one for the rear. Same plugs, they can be swapped, two part numbers. One has a RPM limit, one doesn't.

[Fitron]

Actually, this is not 100% accurate. Look at the Honda VF750/VF1100 series. Two 'igniter boxes' per motor. One for the forward bank, one for the rear. Same plugs, they can be swapped, two part numbers. One has a RPM limit, one doesn't.

I stand corrected. This is the exception, certainly not the rule. Guess you really do learn something new every day!

[xrocket21]

After reading through this whole thread for reference, I realized that there was some confusion over CDI units. There is ever only ONE per engine, no matter how many cylinders. The CDI unit is NOT the ignition coil, as it seems some would think. If you haven't tried swapping CDI's, I'd bet that is your problem. A quick check of the part online shows that it's about $416 from the dealer, and is called a "Converter Unit" by Honda. It's on the "Wire Harness (R.R.)" page of the microfiche.
It looks like this:

http://img.photobucket.com/albums/v6...psk7pwtalv.jpg

-Gary

I think im confused on the CDI, is it like the ECU?

This is what I pulled out to swap with a friend tonight, well, i will at least try mine in his RC.



Is there a separate CDI from the ECU?

this thread has a guy that had the same thing happen, and it was the cdi

CDI box - Honda RC51 Forum : RC51 Motorcycle Forums

[xrocket21]

Actually, this is not 100% accurate. Look at the Honda VF750/VF1100 series. Two 'igniter boxes' per motor. One for the forward bank, one for the rear. Same plugs, they can be swapped, two part numbers. One has a RPM limit, one doesn't.

I call these coil, and they were replaced less than 10k miles ago (plug wire chaffed through, electrifying the tank, shocking my fly on my pants, and in turn zapping my dick)

[xrocket21]

searching "honda rc51 cdi" on ebay shows both units

honda rc51 cdi | eBay

I dont htink I recall seeing that smaller unit.

Im feeling optimistic though that it is the cdi, where ever that is

[Fitron]

Yes, there is BOTH, an ECU, and a CDI. They reside next to each other. The CDI has a single small plug, like the picture in the link shows. The ECU has two wide plugs. Like this:

http://ebayapi.loc8apartltd.netdna-cdn.com/00/s/MTA2NlgxNjAw/z/L5EAAOSwwPhWjtKY/$_1.JPG

[xrocket21]

Hmmmmmmm, well shit, I have the ECU with me. I have been through this bike more than once and I dont recall seeing the CDI. I guess I will have to look again! I hope it is just the cdi!!!!!

[Fitron]

Open this link...part 1 is the CDI, part #28 is the ECU

CycleDesignOnline.com - Honda, Kawasaki, Suzuki and Yamaha!

[xrocket21]

Ill be damned, there she is, #1

- - - Updated - - -

Open this link...part 1 is the CDI, part #28 is the ECU

CycleDesignOnline.com - Honda, Kawasaki, Suzuki and Yamaha!

thanks dude!!!

[Fitron]

Yes sir. I just looked at my RC, the CDI can be seen when you pop the trunk (passenger seat) off. It's located on the right hand side...grey metal box, single small plug. You can't change it out without taking the tail off though! I'll take a picture of it if you want?

[xrocket21]

Yes sir. I just looked at my RC, the CDI can be seen when you pop the trunk (passenger seat) off. It's located on the right hand side...grey metal box, single small plug. You can't change it out without taking the tail off though! I'll take a picture of it if you want?

No picture necessary thank you. I have an aftermarket undertail and everything is zip tied in, so things arent where they normally would be. If its in the tail, I can find it.

Now Im just pissed I changed my work schedule, have my ecu with me, to drive to southern maine tonight to swap ecus to see if my ecu is bad, and it turns out I have the wrong part! I wish I had that damn CDI with me grrrrr

[xrocket21]

HOW TO fix broken converter SP1 - SP2 - Honda RC51 Forum : RC51 Motorcycle Forums


cheaper than $500...

[Fitron]

Well, I suppose it could still be the ECU...though it's actual name is "PGM-FI Unit", which leads me to believe that it controls the Fuel Injection. And since you don't have a fuel injection issue...highly doubtful it's the "ECU". But ya never know! Maybe postpone your trip until you have CDI in hand?

[Fitron]

HOW TO fix broken converter SP1 - SP2 - Honda RC51 Forum : RC51 Motorcycle Forums


cheaper than $500...

Hey that's a pretty cool fix! I've soldered transistors on circuit boards before...that looks like a pretty easy fix!

[xrocket21]

Hey that's a pretty cool fix! I've soldered transistors on circuit boards before...that looks like a pretty easy fix!

Just ordered the transistors from ebay for $35 shipped for all 4....

[Fitron]

Well damn....I hope the CDI is your problem.

[xrocket21]

Well damn....I hope the CDI is your problem.

when its mid june, dead bike, and the parts are under $50, you buy first and ask questions later :o

- - - Updated - - -

shit, the ignition impulse generator and gasket was like $150

its only money, right?

[Fitron]

Haha, damn straight!

[ZX-12R]

Be careful what type of silicone you use to pot the repair. Most clear silicones use acetic acid as a solvent which is corrosive to electronics. Make sure you find an electronics safe product that uses less harmful solvents.

[xrocket21]

Be careful what type of silicone you use to pot the repair. Most clear silicones use acetic acid as a solvent which is corrosive to electronics. Make sure you find an electronics safe product that uses less harmful solvents.

thanks for the tip, I have never heard of that

[number9]

I believe most electronics assemblies use epoxy for this kind of thing.

[jeantarrou]

As previously mentioned, CDI!!! FTW!!!! I would have chimed in a little more forcefully if I knew there was some confusion between the CDI and ECU, it's such a common failure on RC51's, showing the exact same symptoms you described, oh well!

And that DIY repair seems awesome, good luck, hopefully that'll be the fix.