Need a little help with my bike.

[HelluvaEngineer]

I have a 2004 CBR600RR. It has 14K miles on it. The regulator went bad and wouldn't provide enough voltage so I replaced it with a new one. When it went bad it was providing too much voltage (18-30V @ idle). So I replaced it, the stator, and the battery to make sure the charging system wasn't the problem.

I thought the voltage issues were causing the misfire but I was wrong. It still misfires below 4500 rpm. Above 4500 it is perfectly smooth and pulls strong all the way to the redline. I'm not sure which cylinder it is. Here is what I have done so far:

1. Replaced Spark Plugs
2. Run fuel system cleaner through it(Techron)
3. Tried Several different PCV tunes
4. Removed the Power Commander(I'll put it back after I've fixed the other problems)
5. Replaced Air Filter
6. All new fluids(oil, brake, and coolant)
7. Checked for codes(there aren't any)

It has been an issue for several tanks of fuel from different sources so I don't think it is fuel related.

I don't think it is an problem with the FI either. If it was it shouldn't clear up before the secondary injectors come on(5500 rpm) or pull strong to redline. My best guess is ignition but I just don't know where to start.

Any thoughts?

Thanks!

 

[Hayata]

Describe the problem.

What kind of misfire? Does it sputter, knock, etc?

What octane fuel are you burning?

My bike has carbs; does the ethanol in gas these days affect the fuel injectors? It rotted the crap out of my carb o-ring seals.

Is there a test you can perform on your fuel injectors?

Any air leaks on the intake side?

At 10 years seals begin to get some age on them. I'm guessing either injectors or an air leak somewhere.

 

[Bucket99]

I had a similar issue on a 636 Ninja, but mine was higher RPM related, after replacing a battery with a cheap one off of Ebay is when the problems started, injector issues from not enough CCA's. Replaced with a battery that provided proper CCA's per man. spec's and problem went away. Not saying it's your problem just something to consider. Good Luck, it can be frustrating.

 

[HelluvaEngineer]

Describe the problem.

What kind of misfire? Does it sputter, knock, etc?

What octane fuel are you burning?

My bike has carbs; does the ethanol in gas these days affect the fuel injectors? It rotted the crap out of my carb o-ring seals.

Is there a test you can perform on your fuel injectors?

Any air leaks on the intake side?

At 10 years seals begin to get some age on them. I'm guessing either injectors or an air leak somewhere.

It is a sputter at low rpm. The only reason I don't think it is the Injectors is that it makes it to redline with no problems. If there was an injector problem it shouldn't regain power should it?

The ethanol shouldn't be a problem. The manual specifies up to 10% ethanol is OK and I normally run ethanol free fuel(not that the guy before me did).

Intake is sealed up tight. Goes through the air filter through 4 velocity stacks and four throttle bodies straight into the intake.

 

[HelluvaEngineer]

I had a similar issue on a 636 Ninja, but mine was higher RPM related, after replacing a battery with a cheap one off of Ebay is when the problems started, injector issues from not enough CCA's. Replaced with a battery that provided proper CCA's per man. spec's and problem went away. Not saying it's your problem just something to consider. Good Luck, it can be frustrating.

I put in a high quality battery. Lithium ion. I don't remember the exact specs but it is rated more then it needs to be.

 

[rhbridges]

Could be a coil, injector, or any related wiring causing your described problem. I would try to isolate the problem cylinder by disconnecting injectors one by one. Once you have determined the cylinder, swap the coil with one from a good cyl. If the problem moves to the other cyl you've found the culprit. If it doesn't move try the same technique on the injector. If you still have the problem on the same cyl you'll have start looking at the wiring.

 

[whocares5254]

check your plug wires for cracks and make sure they seat tight onto the plugs.

 

[HelluvaEngineer]

Could be a coil, injector, or any related wiring causing your described problem. I would try to isolate the problem cylinder by disconnecting injectors one by one. Once you have determined the cylinder, swap the coil with one from a good cyl. If the problem moves to the other cyl you've found the culprit. If it doesn't move try the same technique on the injector. If you still have the problem on the same cyl you'll have start looking at the wiring.

Worth a shot and easy enough for the coils but it is a huge pain to swap injectors between cylinders. The thing as two injectors per cylinder. I'm trying to locate rebuild kits for them but haven't had any luck with it.

 

[HelluvaEngineer]

check your plug wires for cracks and make sure they seat tight onto the plugs.

Its over cylinder coils. I'll hook up my fluke and ensure that all four are getting a signal but it really shouldn't be the wires as it is low voltage at that point.

 

[rhbridges]

Worth a shot and easy enough for the coils but it is a huge pain to swap injectors between cylinders. The thing as two injectors per cylinder. I'm trying to locate rebuild kits for them but haven't had any luck with it.

As you said it clears out up high, so I would skip swapping the secondary injectors, and only swap primary injectors. Also check for air leaks by spraying something around the intakes between the throttle body and head.