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I had a hella bad noise when a coil went out. I was missing two cylinders and coil would go in and out. Was a bad connection. It made a crazy clunking snapping sound. Little backfiring... Ran perfect after fixing the wire. I realized it was only running on two during a cold start and tracked it down. Maybe the loose connection would make the coil fire off prematurely resulting in the piston slap. I don't know.
 

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Discussion Starter #22 (Edited)
The throttle body plates or butterflies have a crescent shaped black rubberized type coating.......do not attempt to clean this at all, per Honda.
Thanks fizzy, I will refrain from cleaning the throttle bodies at all. They don’t appear really “dirty” to me considering 22 yrs old.
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I do see the rubber crescents you mention, looks to be in decent shape, not perfect, but decent, so don’t want to make them any worse.
 

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Discussion Starter #23 (Edited)
I had a hella bad noise when a coil went out. I was missing two cylinders and coil would go in and out. Was a bad connection. It made a crazy clunking snapping sound. Little backfiring... Ran perfect after fixing the wire. I realized it was only running on two during a cold start and tracked it down. Maybe the loose connection would make the coil fire off prematurely resulting in the piston slap. I don't know.
Creepy, you got me thinking and digging so I pulled the ignition coils to do a resistance test and thought I found an issue.

Started with #2 & #3 coil and got 2.4 ohm on primary coil and weirdness on the secondary coil, it kept bouncing around between 3 and 6 Mega ohms. I couldn’t get a stable reading. But from what I could find that is a factor of 10 too high. Secondary should be in the Kilo ohm range.

Thus my second problem, I have spent about an hour going through the service manual and can’t find the required reading for the coil resistance. Internet has provided many different values for both Pri and Sec coils, nothing definitive.

So I figured pull #1 & #4 coil and test it for a comparison point. I got 2.4 ohms on primary and 33.1 K ohms on secondary.... so it looks like #2 & #3 coil is bad.......

Figured I would test #2 & #3 coil again to confirm it’s bad..... Crap.... now I get 2.4 ohm and 33.6 K ohms.......

Only thing different is I took the spark plug wires off and reattached between bad tests and good test.

Does anybody know “good” values for the primary and secondary resistance?

It seems like 2.4 ohm is too low and 33.1 K ohm is too high? But the two coils are consistent so that implies correctness.

Thanks in advance.
 

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I suggest you test the resistance of the plug leads and caps as well....... caps can go bad with age. Especially if they have resistors inside...... from memory most plug caps have 5k ohms R but the resistor can degrade in time and go out of spec. Maybe this caused the coils to misfire?

(y)
 

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Discussion Starter #25
I suggest you test the resistance of the plug leads and caps as well....... caps can go bad with age. Especially if they have resistors inside...... from memory most plug caps have 5k ohms R but the resistor can degrade in time and go out of spec. Maybe this caused the coils to misfire?

(y)
Aussie Dave,

I tested the full wires, from plug cap to the connection end for the coil and got 5.3 K ohms, 5.3 K ohms, 5.5 K ohms and 5.6 K ohms.

So that seems consistent and close to your memory. So I would assume the wires look good.
 

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Yes that would be all good... around 5k ohms is good.... maybe there was just a connection issue when it played up...... coils are hard to test, last time I spoke to a mechanic they mentioned load testing to find a fault as they often don't falter until they are put under load. There are after market coils available - I think 'Dyna' is a brand that speedway and drag racer guys use, but there would be several others if oem items are no longer available. Dr Google may be able to help...... if the coils still play up when riding. I suppose the problem is fitting them to the BB - not much room in the original position.......
 

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Yes wire values are good. Coils I want to say sound good as well. But you need to be mindful how you meter them. Primary sides sound about right at 2 to 3 ohms
Secondary at 30k too. Where you have to be careful is how you place leads. Because they are wasted spark coils how you read them is different than a normal coil. I don't have the Factory CSM Common Service Manual in front of me right now. So I can't give you a definite answer on testing sequence. But I want to say it's a little tricky. You can get readings like you have and he good. Because of the way the coils are built. Primary to primary. And primary to secondary switches on the terminals.
 

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Discussion Starter #28
Update:

I got the engine closed back up, spark plugs in and filled with oil. Left the gas tank and ignition coils off and cranked it with the starter motor.

Turn fine so my worse case fear that something broke in the engine is completely gone.

I have been screwing with the coils, wires and plugs boots a bunch.... installed the original boots on the new coils with new wires and the coil for #1 / #4 tested fine on the primary and secondary sides. But #2 / #3 was fine on the primary, but weird on the secondary side. It bounced around but was always in the M ohm range.

Went piece by piece and determined it to be one of the spark plug boots. Got NOS Honda boot off of eBay and all test good now.

So it is looking like Creepy’s suggestion about a spark issue is the most likely cause.

Next step to install coils, air box and gas tank and be really happy when it starts right up and purrs like a kitten, hopefully.
 

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Discussion Starter #29 (Edited)
Update #2:

Hooked up the new ignition coils, installed the air box and gas tank..... put in about 1/2 gallon gas and tried to start it.

Nope, it cranks fine but no fire. I kept the starter motor going for 15 seconds at least on several occasion, not a sputter, no sign of life.

I hear and feel the fuel pump prime up, the FI light goes off after a few second. The Neutral light is on and the side stand is up, it is on the center stand. The kill switch is in the run position.

I tried so much that I put on the charger until it was 100% and tried again today. Same, no fire.

Prop’ed up the gas tank, keeping everything hooked up, removed the air box, opened the throttle plates and cranked again. I don’t see anything “squirting” into the throttle tubes, should you be able to see the injector output in the tubes?

Pulled both #1 and #2 plugs (one from each coil) and checked for spark. There was spark.

Pulled the fuel tank output line at the fuel rail and turned on the ignition, gas came out, so the new pump appears to be working.

Pulled the fuel return line from the FPR hoping I could turn on the ignition and verify gas is getting to the other end of the fuel rail, but the tank just starts draining, so I canceled that idea.

Any suggestions for the next step?

Summation of everything done so far:
1) FPR and sleeve replaced.
2) Ignition coils and one definitely bad spark plug boot replaced.
3) Fuel pump, filter and all hoses in the tank replaced with new.
4) Fuel tank cleaned.
5) Ignition key, fuel tank key and seat locks replace,
- I say this because replacing the seat lock required moving the ECM out of the way, it was not disconnected and I was careful with the connectors, but is was moved out of it’s 22 yr previous spot. I would doubt any damage occurred but anything is possible.
 

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We still don't know what the initial "something broke" noise was?

What happens if you spritz a little petrol down the intake throats while trying to start?

Check for hidden codes, there is a 2 pin female connector aft of the ECU that can be shorted with a paperclip. This will give up any stored 2 digit codes in Morse code fashion.

Has there ever been an alarm fitted? Are there any wires that don't look factory and you don't know what they do?
 

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Discussion Starter #31
We still don't know what the initial "something broke" noise was?

What happens if you spritz a little petrol down the intake throats while trying to start?

Check for hidden codes, there is a 2 pin female connector aft of the ECU that can be shorted with a paperclip. This will give up any stored 2 digit codes in Morse code fashion.

Has there ever been an alarm fitted? Are there any wires that don't look factory and you don't know what they do?
Not 100% sure, but maybe 80% sure the initial “something broke” sound was a bad ass backfire as Creepy said happened to him, because there was definitely a bad / going bad spark plug boot on #3.

Haven’t tried spraying gas into the intakes, as I was messing with it I was eyeing my can of carb cleaner thinking ”Hum, spray some of that in there”.... but wanted to get opinions on why I wasn’t seeing gas spraying from the injectors.

Yeah, I was thinking’s I need to check for ECM codes, but couldn’t remember how, I will do that next.

Never had an alarm, that I know of, I am not the first or second owner... but no signs of it.... All wiring seems very OEM and in good shape.

I was trying to remember if during tearing down I removed any connectors I might have left off, I don’t think so and have looked and see no connectors off, but it could be hiding.
 

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Discussion Starter #32 (Edited)
Nope, no ECM codes. Got 9 blinks and was excited, till I read that indicates IAT connector issues and I have the air box off, so I reconnected the IAT sensor and went through the clear the jumper steps.

Now no blinks when the black connector is jumped.

Plus I couldn’t resist and sprayed some carb cleaner down #1 tube while cranking and nothing. I didn’t spray a lot, but what I thought enough to get some sputter.... No sputtering, no nothing.... So maybe I need to rethink my definition of “got spark” on #1 and #3 from earlier. I have never grounded a plug on the engine and looked for spark before so I have no frame of reference for a “good spark....

There was definitely spark on both, but not like “wow” that’s a spark.... Should they be impressive sparks or just kinda “tingly“ sparks.
 

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Just kinda tingly is about right it won't look like a welder flash.
 

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Shoot some fuel or even bettet starting fluid into the airbox ports
If it doesn't pop your not getting spark. If it does then your not getting fuel. If you checked with the throttles wide open. Then you probably set in clear flood mode. Cranking with the throttle wide open shuts the injectors off.
 

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This is a FI bike. Are you hearing the fuel pump kick on for a short bit when you turn the key on? That connection can hide on you. Or your pump might be bad or you don't have a good connection. See if you have power up to your fuel pump. I know it's obvious but I have missed the obvious before.

Sent from my SM-N960U using Tapatalk
 

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Discussion Starter #37 (Edited)
Shoot some fuel or even bettet starting fluid into the airbox ports
If it doesn't pop your not getting spark. If it does then your not getting fuel. If you checked with the throttles wide open. Then you probably set in clear flood mode. Cranking with the throttle wide open shuts the injectors off.
Beestoys, I saw another post here where you mentioned “clear flood mode” and I was never able to find how to “clear” the “clear flood mode” in the posts. Is there away to do that? How to you get out of that mode?

I would think when I reset the ECM code (shorting the black connector) after reading the codes and reshorting it, which I did.

But I have most definitely had the throttle full open while cranking, to look down the tubes and yesterday to spray in carb cleaner.
 

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Dug
Sorry I didn't explain further. It only goes into that mode when the throttle is held wide open when cranking. Once you release or come off wide open the injectors will start firing again
 

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Discussion Starter #39
Dug
Sorry I didn't explain further. It only goes into that mode when the throttle is held wide open when cranking. Once you release or come off wide open the injectors will start firing again
Well dang, so that doesn’t account for why the injectors are not firing now. Thanks for clarifying.
 

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Discussion Starter #40
This is a FI bike. Are you hearing the fuel pump kick on for a short bit when you turn the key on? That connection can hide on you. Or your pump might be bad or you don't have a good connection. See if you have power up to your fuel pump. I know it's obvious but I have missed the obvious before.

Sent from my SM-N960U using Tapatalk
XXGUY, yes the pump definitely primes, I hear it with every turn of the key or flip on of the kill switch, I even feel vibrations on the top of the tank.
The fuel pump is brand new. Plus like I said with the output line of the fuel tank removed from the fuel rail and turning on the ignition switch gas comes out of the output line quite well’ly.

I haven’t measured the pressure, saw that method mentioned in the service manual, but seems like it would require purchasing a special pressure gage setup and I was hoping to go through simpler checks first.
 
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