Different cylinder head temperatures

Kiwi961

Kiwi961

Joined
Nov 22, 2016
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Hi All,
I’ve noticed that when the bike starts up that the right hand exhaust pipe gets much hotter, much quicker than the left one - the plugs are often different colours too. What can cause that? And is it something to be concerned about?
 
I’m interested in this also as mine is exactly the same.
I thought it may be something to do with lambada sensors.
Are you still running yours?
My right header pipe is much bluer than left.
 
Sounds like the O2 sensors. I don't have that problem any longer since my O2 sensor elimination.
 
Figure 2 hrs . Take off gas tank , remove electrical plugs from injectors , remove bolts holding fuel rail , remove fuel rail , injectors should just pull out.
 
Hi,
I had a few weeks ago also one almost cold exhaust. Checked everything, also exchanged the cam valve. Cleaned the injectors etc. Finally checked also the compression. No compression at all and could have done with just my fingers instead of a compression meter.
The exhaust valve spring was broken. Exchanged it. Now everything is fine again.
But the new spring is a bit different and designed such that less stress is in the spring material. I planned to exchange the other three also.

Sjoerd
 
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Are the new springs the Bee Hive shape ? What year is your bike ? I have a late 2014 and it has the Bee Hive type springs.
 
My Dominator with megaphones (no O2 sensors) does this as well.
I’ve checked the compression, tested the spark, checked the plugs, plug gap, and tested the spark plug wires with my fluke multimeter.
I’m running iridium plugs and Richards wires.

I “only” run Sunoco 260 GT 100 octane race gas.
The spark plugs look beautiful and no signs of spark knock. Without doing a injectior balance test on both injectors I just let it go. It runs great and no problems period.
 
TonyA said:
Can that affect the timing on the one cylinder ? Its easy enough to try hey ? Try out a new Bosch cam sensor ?
Click to expand...
A crank sensor controls the injector firing / spark firing.

I’ve often thought of pulling off my throttle bodies to tune and blue print them. I’ve never had one off of either of my Norton’s and I’m curious how many cfm they flow.
I’d be interested to see if porting one would provide any gains in power and performance. At the very least gains in running.
 
Same with my CR. Egli said that this is normal, but I don‘t know why. Have to ask him next time...
 
Coincidentally I called Rob at the factory last week because I noticed that the right exhaust was firing regularly, but the left seemed to be slightly misfiring at tickover despite the bike pulling like a train. More an observation than a problem. He replied;

Cylinder 1 fires first, and as that starts its power stroke it actually steals fuel from cylinder 2 (hence why cylinder 2 on a Norton always runs hotter), in the aftermarket maps we give overrun fuelling (not allowed in euro 4), so that could well explain it.
 
Clive said:
Coincidentally I called Rob at the factory last week because I noticed that the right exhaust was firing regularly, but the left seemed to be slightly misfiring at tickover despite the bike pulling like a train. More an observation than a problem. He replied;

Cylinder 1 fires first, and as that starts its power stroke it actually steals fuel from cylinder 2 (hence why cylinder 2 on a Norton always runs hotter), in the aftermarket maps we give overrun fuelling (not allowed in euro 4), so that could well explain it.
Click to expand...
How is #1 stealing fuel from #2 when they don’t share a injector and the fuel rail is under constant pressure?
 
Does Rob mean that the program for Injector 2 compensates or (tries to compensate) for this phenomenon ? And when he said steals does he mean from the available fuel in the rail ? I think that a multi cylinder machine would have the same problem too ? Just wondering .
 
There is a feed for the air bypass for the idle air motor which sits very close to the front of the throttle bodies, so from what I am told by the calibration guys that's what happens. I believe that the ECU compensates, but it still isn't unusual for #2 to run hotter. It isn't anything to worry about, just a further quirk of the engine.
 
Oh I see what you are saying now. That the vacuum created in #1 throat can steal from #2 through the IAC passage .
 
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