Rubbermount_EFI Cylinder temps - Why big difference?

[sungod]

Originally Posted by bustert

hummmm????
like the sun rising and the sun setting???
toilet swirl right or left???

High tide /Low tide

[XL Dane]

Originally Posted by sungod

How do your plugs compare?

Good idea, I checked and they look exactly the same.

[XL Dane]

Originally Posted by MODO SIKLER

Plugged exhaust for one cylinder? ...due to rats or some other nesting critter? Happens commonly in certain areas.

Thanks for the idea, but no obstruction in the exhausts.

[XL Dane]

Originally Posted by shanneba

Check for exhaust leaks at the head and at the O2 sensors.

A leak that allows outside air to the O2 sensor would have the ECU believe the mixture was lean, causing it to richen the mixture. (I would suspect a possible leak in the rear exhaust)

Do you have a PowerVision tuner?
If you do you can log the O2 sensor voltages front and rear.
You can also log the Rear cylinder head temp to see how it compares to your thermographic pictures.

Yes I have PV tuner, so I will try to see if front and rear are same. Will also try to check for intake/exhaust leaks.

[XL Dane]

Originally Posted by rejeanprimeau

Front exhaust, heat travel back, been knowed since VTwin are born.

But this is also while idling..

[XL Dane]

Originally Posted by sungod

Is the bike upright or on the stand at idle? Just wondering if the angle has any
impact on cylinder temp.

It doesn’t seem to make a difference.

[shanneba]

Setup your PV log to log these items:

RPM
ET
MAP
Set AFR ( on 2014 + you may see a Lambda value instead of AFR ratio)
VE Front
VE New Front (Ve with fuel trims)
Front CLI (Short term fuel trim)
Front AFF (Long term fuel trim)
VE Rear
VE New Rear (Ve with fuel trims)
Rear CLI (Short term fuel trim)
Rear AFF (Long term fuel trim)
Front O2 V
Rear O2 V
IDC.F
IDC.R
IAT
Advance F
Advance R
INJ PW F
INJ PW R

The VE New and fuel trims will let you see the ECU adjustments.
The CLI and AFF are at 100 when no change is being made or you are in open loop using just the set VE values.

[kitabel]

The original cause of the front cylinder running hotter (that's why the baffle is there)?
The rear cylinder gets oil thrown off the flywheels, and the front cylinder doesn't.

[brucstoudt]

front cylinder running hotter is a known H-D trait post#17
http://xlforum.net/forums/showthread...=420459&page=2 i have no doubt the additional oil the rear cylinder gets splashed with also has a cooling effect.

[tussuck]

I thought the 'tuners' set the rear jug to run a little richer which helps in cooling given its shrouded by the front one when the bike is underway. I would say this is normal and not to worry about it.