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Lean fuel to air mixture
Posted: Mon Dec 24, 2007 5:11 am
by cone
I submitted a post regarding the fitting of a aftermarket silencer and got a good reply but I am still not convinced that all is well.
Apparently all boxers after 2001 suffer from a lean fuel to air mixture (something to do with strict EU regulations) and fitting an aftermarket exhaust makes the mixture even leaner especially at high altitudes.
I would hate to spend a lot of money on the pipe I have in mind and then go and burn a hole in the piston.
Posted: Mon Dec 24, 2007 5:23 am
by DJ Downunder
Where did you submit this post?....I think they're having you on..
I've done more than 50,000 klms with no can (silencer) at all.
The guys who did the Long Way Round did a ride of more than 30,000 klms with aftermarket exhausts on their bikes.
Don't worry...Just do it.
DJ
Posted: Thu Dec 27, 2007 12:19 am
by OU812
+1!
Posted: Thu Dec 27, 2007 4:00 am
by cone
Thanks for the input. There has been a few complaints locally about bikes running hot, pinking and plugs not lasting and even piston damage all as a result of the air/fuel ratio which is incorrect and which cannot be adjusted. There is a garage in Cape Town now selling add on power unit which apparently rectifies the problem and gives about an extra 5 kilowatt. I will be riding the lovely roads in the Eastern Transvaal next week but unfortunately still with the original pipe.
stating the obvious
Posted: Thu Dec 27, 2007 5:12 am
by zax1150
Cone,
the reason you're seeing problems in SA is height above sea level is between 1600-2000m so oxygen is 20% less, pinking is the telltale there!
therefore the std air/fuel ratio settings are too lean,
If your bmw dealer cannot or will not rectify
then chip it
Posted: Fri Dec 28, 2007 3:09 am
by Trompie
Cone, I stay in Gauteng close to Jo'burg and don't have any problems so far even with the can removed with only a stubby and cat. I will post some pics of my Rockster later. It's steel grey with orange rims and stripes
.
Posted: Fri Dec 28, 2007 12:53 pm
by boxermania
cone
You are right, higher altitudes do exarcerbate the lean problem of the boxers, that doesn't present much of a problem at 300m altitude.
First insure that your bike is in a good state of tune, TB's in sync and regap your plugs .003" less than factory.
If there are still problems the easiest thing to do is obtain a Techlusion R259 and tune as per the factory recomendations. Do increase the mid range and top end pot by one whole number. That should solve all your problems with an aftermarket can.
The chip and even a pressure regulator from a prior generation K bike will also provide the same results, although the amount of work to install is significantly more.
Can you share with us what the local garage is doing?.....inquiring minds want to know.