Dear friends,
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I posted this message on the general forum, but I guess it belongs here, so I'll make a copy here:
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Let's try to make it short,
I have a 08 CVO Springer with 2.000 miles on the clock
My rear cylinder's exhaust&nbsp\\;\\\\\\;as you start has a lot less gases coming out while idling, cold or warm. If I put my hand by the exhaust outlet, while the front sends a clear exhaust impact on my hand, the rear one is just a mild "version" of that of the front one......
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It used to have that lousy butterfly on the rear header (euro bike), but I installed a set of Softail headers I bought from the US... Total waste of money. Put a TMax with new maps and an SE Sucker, and Rineharts (mufflers)....you guessed it, just the same.
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Both plugs look right and same white ceramic look, so what is going on here? If I had different inlet tracks and butterflies I would have sworn that the front cylinder was pulling the rear one&nbsp\\;\\\\\\;and that all I needed was a carb/injection adjustment, but being only one inlet and butterfly, how come the rear is not doing its job same as the front?
No oil burn or other weird or catastrophic issues (I thought I'd mention....)
Bike runs good and much better now with open pipes TMax and bigger inlet, so what the h€ll is going on?
Now I know there is something definitely wrong, As I start with a cold engine the front cyl catches-up temperature much faster than the rear, actually and for a while, the rear cyl blows cold exhaust gases while the engine idles or slightly opening the throttle. While waiting for my temperature laser measuring device I used a temperature tester (protected cable with contact at the end) and when introduced to the exhaust of each cylinder I got 100ºF lower readings from the rear one. Since plugs look fine, my guess is that for some reason the injector for the rear cylinder is not working properly. This can be the injector itself or something wrong with the ECM, but this cannot be since I had the same problem with the standard ECM, this alone discards any problem with the Thundermax. Over 2500 rpm bike goes well, but need the IR thermometer to check temps after a hard ride. We are talking here about a CVO 08 with 110 inch motor, that compared to my 07 FXDC Dyna is more of a beast when you open the throttle..., so even though the rear cylinder seems to be lazy at first, if you whack the throttle open while riding, it makes my Dyna more like a kitten......
As I said, I'm totally baffled with this issue

Best Regards,
Spanish Flyer

 

It sounds to me like there is something that is a miss with your computer, it seems that for somereason your computer is cutting off the rear cylinder, this happens at high temps, or that there is something wrong with the O2 sensor, telling the onboard computer that it is too rich, I would definitly have the dealership check it out. Under the high heat mode the rear cylinder acts only as an air pump to cool down the engine, and since it is usually the rear cylinder that overheats that is the one that the computer cuts off. my dealer offered for one time only to turn off this feature, I refused, I added better flowing exhaust, more fuel through a new fuel processor, and installed the K&amp\\;N heavy breather to allow for better air flow. I hardly ever notice mine going into the "parade mode" as the moco calls it.

[IMG]local://upfiles/47348/9A62AF9A55C04CBF88EF7119FA829DDB.jpg[/IMG]

 

Hi dope_man_21,
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As I said, I've changed the ECM from standard to ThunderMax with Autotune, so this "parade mode" no longer exists on my bike\\; it is on the ECM I keep on my garage shelf..... I´m more inclined into thinking that the starter solenoid/decompression valve is faulty and I'm losing all compression at low rpm on the rear cylinder, but it is just a wild guess. I will need to do a compression test and go on from there.
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I have put a video up for all of you to see (or listen actually). I put my hand close to both&nbsp\\;the exhaust can outlets and even though for me the sound was completely different depending on which one&nbsp\\;I put my hand on, on the video the sound is not all that different. The impact my hand felt from the lower (front cyl.) was so much stronger that I could hardly keep my hand. the top (rear) one I was able to completely cover. Try and listen to the difference. As you say, it feels as if the rear cylinder is just acting like an air pump. The video was taken while the engine was cold.
&nbsp\\;http://es.youtube.com/watch?v=v1R_p6idsGA
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See if you notice the huge difference I felt on my hand by judging the sound and exhaust gases hitting my hand.
Spanish Flyer

 

I just removed the TMax from my machine after it started doing some very strange things after the bike got hot. It eventually left me on the side of the road and I was forced to have a foreign HD dealer remove the entire system (including O2 sensors) and re-install the stock ECM and O2 sensors. I paid for a custom dyno tune and they created a custom map for my setup. The bike has been running perfectly since and I will never change the stock ECM again. Even though Zippers has an excellent product it shold NOT be used on any machine that is still under warranty. The MOCO will NOT warranty anything if the bike is being controlled by an ECM they do not support. I just learned this the hard way !!
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My suggestion, remove the TMax system and re-install your stock ECM (you will find the bike starts up much better after you do this, mine did). Buy a SERT and have a custom map made for your setup by a competent dyno certified shop. After your bike is up an running with the stock ECM and a well tuned map have an HD dealer diagnose the rear jug problem under warranty. Attempt to return the Tmax system to Zippers for a full refund if possible.

 

My guess is you are having some sort of problem with the ACR (Automatic Compression Release) system on your bike that is directly controlled by the ECM. You will NOT be able to get this repaired under warranty if the TMax is installed on your machine. I know that Zippers has had numerous issues with the ACR systems which has caused hard starting issues for alot of customers (including me) that has not yet been 100% corrected.
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I have also been told there is a bulletin from HD about some problems with the ACR's not properly closing after the bikes with 110 motors are started. This bulletin does not blame the ecm from what I remember, it is an issue with the ACR's themselves.

 

have you done a compression check?