'06 Kawi ZX636 - Running Too Rich Need Help

kickstartt

kickstartt

Well-known member
Hi guys:

I posted a thread previously about fuel consumption issue with my bike ('06 ZX636), now I know the problem is bike running rich
Symptoms:
- black spark plug tip with dry carbon
- jerky throttle
- loud exhaust noise
- bad fuel econ

Spark plugs are new and now ruined;
air filter clean
fuel filter good (since no symptoms of bad filter)
battery 1 year old
bike is fuel injected

I would like suggestions from anybody whose had bike running rich issues before on how I can fix it before taking it to the shop?

Greatly appreciated.
Thank You
 
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Would be useful if you posted photos of the ruined spark plugs.

Have you checked for a vacuum leak? That would be causing a lot of your symptoms.
 
Matt Rain said:
Would be useful if you posted photos of the ruined spark plugs.

Have you checked for a vacuum leak? That would be causing a lot of your symptoms.
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No I didn't take photos, ok I shall look into that tonight...
Thank you!
 
BTW what do you mean by loud exhaust noise? Backfiring or just an overall louder sound? If it's the latter, you most likely have an exhaust leak. Check your header bolts and re-torque to spec.
 
Matt Rain said:
BTW what do you mean by loud exhaust noise? Backfiring or just an overall louder sound? If it's the latter, you most likely have an exhaust leak. Check your header bolts and re-torque to spec.
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It is louder overall, it wasn't as loud before.
It just had a valve clearance check recently at 25k km, the mech said it was fine so valves weren't touched, only replaced new spark plugs (which are now covered in carbon at the tip).
Cam chain tensioner was replaced cuz it was making noise (common issue with my bike model)
Bike was running perfectly fine before valve check.
 
Are all four spark plugs the same appearance? Is the fault indication lamp on?

If the onset of these symptoms coincided with the valve clearance check and tensioner replacement, I would be interested in the procedure that was used to change the cam chain tensioner. It is easy to screw this up, resulting in cam timing that is off by a tooth because the tensioner wasn't holding the guide against the chain. Cam timing that is off by a tooth will wreak no end of havoc.

It is also necessary to follow the proper assembly sequence with those tensioners. They have to be installed in the retracted position and then allowed to spring out after the bolts have been torqued. Depending on who did the work, they should know that ... or they might not.

Check the cam timing.
 
Brian P said:
Are all four spark plugs the same appearance? Is the fault indication lamp on?

If the onset of these symptoms coincided with the valve clearance check and tensioner replacement, I would be interested in the procedure that was used to change the cam chain tensioner. It is easy to screw this up, resulting in cam timing that is off by a tooth because the tensioner wasn't holding the guide against the chain. Cam timing that is off by a tooth will wreak no end of havoc.

It is also necessary to follow the proper assembly sequence with those tensioners. They have to be installed in the retracted position and then allowed to spring out after the bolts have been torqued. Depending on who did the work, they should know that ... or they might not.

Check the cam timing.
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I shall look into that too...


fiddleguy said:
Were the correct plugs installed (heat range)?
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Yes the plugs are the right ones
 
Have you contacted the shop that did the work? have them rectify it ? Wasn't it 109 Cycle ?
 
Rich running could be caused by a defective engine or air temperature sensor. It could also be the associated wiring to the ECU (eg. poor contact at the plug, broken wire, poor ground).

The ECU has to know the operating temperature of the engine and the ambient air temperature to properly select the correct fueling map. If the sensor does not feed back the proper temperature, the incorrect fuel map may be selected. Since the engine is running rich, it might be because the ECU thinks the air temperature is very cold and is selecting a richer fuel map. The plug may have been dislodged when the service was performed.

Check and clean the connections to the temp sensors. Check the contacts in the plugs to see if any have been accidently pushed through. Check the resistance of the temp sensors and see if they match specifications. Replace the temperature sensors themselves if you suspect them to be defective. Check the connections at the ECU to make sure it is solid and clean. Check the ground connections to the frame to ensure they are solid and reliable.
 
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^ Temp sensor or wiring problems would have other symptoms, though (and the original poster hasn't stated this one way or the other).

On that bike, the same sensor is used for the ECU as for the instrument panel. If the coolant temp sensor is reading in a wrong range (because the sensor itself has gone bad), it will display an abnormal coolant temperature on the instrument panel. If the coolant temperature sensor is unplugged, it will give a fault warning and the underlying code will be associated with a "... circuit open or shorted to ground".

It's very easy to forget to plug the intake air temp sensor into the airbox (Electrically connected, but physically hanging loose instead of sitting in the grommet in the airbox). But normally this won't cause a gross fueling error. The temperature of the air circulating around the bike won't normally be too different from the temperature of the air going into the engine. If this sensor is electrically disconnected because someone forgot to plug it in, it will give a fault indication and a "... circuit open or shorted to ground" in the associated code.
 
Brian P said:
Are all four spark plugs the same appearance? Is the fault indication lamp on?

If the onset of these symptoms coincided with the valve clearance check and tensioner replacement, I would be interested in the procedure that was used to change the cam chain tensioner. It is easy to screw this up, resulting in cam timing that is off by a tooth because the tensioner wasn't holding the guide against the chain. Cam timing that is off by a tooth will wreak no end of havoc.

It is also necessary to follow the proper assembly sequence with those tensioners. They have to be installed in the retracted position and then allowed to spring out after the bolts have been torqued. Depending on who did the work, they should know that ... or they might not.

Check the cam timing.
Click to expand...

+1 - bike WAS ok before tensioner change....and the change in exhaust sound is an indication cam timing is off a tooth.....also carbon on plugs is another indicator of cam timing that is off....also poor fuel economy is an indicator. but the real giveaway is the change in exhaust sound. the change in exhaust sound is what convinced me cam timing is off-good observation on your part.

i wouldn't continue riding the bike the way it is, engine damage is possible.
 
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boyoboy said:
+1 - bike WAS ok before tensioner change....and the change in exhaust sound is an indication cam timing is off a tooth.....also carbon on plugs is another indicator of cam timing that is off....also poor fuel economy is an indicator. but the real giveaway is the change in exhaust sound. the change in exhaust sound is what convinced me cam timing is off-good observation on your part.

i wouldn't continue riding the bike the way it is, engine damage is possible.
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Thank you everyone for your advices! I shall look into CAM timing.
Frikeyguy is too far from me, I'm in EastYork.
I will take the bike to a different shop close by.

Will keep u guys updated once its fixed.

Thanks again everyone
 
frekeyguy said:
Have you contacted the shop that did the work? have them rectify it ? Wasn't it 109 Cycle ?
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I don't feel like takin it back to them anymore, obviously they don't know this bike...
 
Also make sure that any hoses involved in the throttle bodies are correctly routed and haven't been kinked, unplugged, or otherwise damaged.
 
Just as a follow up to you all helpful folks, according to snow city, the running rich problem was caused by throttle body alignment being off...
 
kickstartt said:
Just as a follow up to you all helpful folks, according to snow city, the running rich problem was caused by throttle body alignment being off...
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What is a 'throttle body alignment' that 05/06 uses oval throttle bodies - they go in/out one way only.
 
johnscruiser said:
I think he means they weren't sync'd:

[video=youtube;UmLwyAPMBLI]http://www.youtube.com/watch?v=UmLwyAPMBLI[/video]
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So that's what they do... thanks for the video!
 
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