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[Spanish Flyer]

Hi people,

I have a problem as I start the engine and even when the engine is hot which is very clearly noticed as the engine idles.
The fact is that when I get the engine going, the rear (top exhaust) on my FXSTSSE2 08 blows half as much exhaust gases as the front (lower) pipe; putting a temp probe in the silencers I get a 100ºF lower reading from my rear cylinder, as if there was no fuel getting in the engine or as if the ACR (automatic compression release) valve remained open thus lowering the compression even after the engine started. I've had this problem for quite some time now, even with the standard ECM (now I have the ThunderMax & AT). Thing is that the bike runs well over 2500 rpm and the engine has never stalled. I just wonder how much power is lost if one ACR remains open at all times 

Does anyone know how to cancel the ACR's automatic operation, to see if I notice any difference? I mean removing a fuse or something simple, because I don't want to have to remove my fuel tank now that it's full.....

And what are the symptoms of ACR failure?

Check out this video I made where I clearly feel the huge difference between the rear cyl exhaust impact and the front one on my hand as the cold engine idles. Plugs are fine (both look exactly the same with the ceramic perfectly white)

Bike has only done 2.000 miles.

 http://es.

Need help here.......

Best Regards,
Spanish Flyer

[megavolt17]

The front cylinder has it's own exhaust, but the rear cylinder splits it exhaust between the two sides - at least with the stock exhaust.  I have at least twice as much exhaust out the right pipe as out the left but that was the same with my 1998 Road Glide.

Not sure how you tell if the ACR is still open, or stuck closed.  At times my bike barely will turn over and I wonder if the ACR is stuck closed.  At times when cold and I am gently moving down my driveway is feels as if it's loping down the driveway on only 1 cylinder.  When warm or I give it any gas it acts normally.

I decided just to drive it and stop worrying about what it may or may not be doing.  It did OK on the dyno, and it acted the same back then as it does now so there can't be too much wrong with it.

[BIGDOG]

If your running 2 into 2 exhaust you will get more flow out of one pipe than the other. That would explane more heat out of one pipe . I would tend to believe that the plugs looking equal and of proper color would suggest all is fine.

[RedDevil]

Hi people,

I have a problem as I start the engine and even when the engine is hot which is very clearly noticed as the engine idles.
The fact is that when I get the engine going, the rear (top exhaust) on my FXSTSSE2 08 blows half as much exhaust gases as the front (lower) pipe; putting a temp probe in the silencers I get a 100ºF lower reading from my rear cylinder, as if there was no fuel getting in the engine or as if the ACR (automatic compression release) valve remained open thus lowering the compression even after the engine started. I've had this problem for quite some time now, even with the standard ECM (now I have the ThunderMax & AT). Thing is that the bike runs well over 2500 rpm and the engine has never stalled. I just wonder how much power is lost if one ACR remains open at all times 

Does anyone know how to cancel the ACR's automatic operation, to see if I notice any difference? I mean removing a fuse or something simple, because I don't want to have to remove my fuel tank now that it's full.....

And what are the symptoms of ACR failure?

Check out this video I made where I clearly feel the huge difference between the rear cyl exhaust impact and the front one on my hand as the cold engine idles. Plugs are fine (both look exactly the same with the ceramic perfectly white)

Bike has only done 2.000 miles.

 http://es.

Need help here.......

Best Regards,
Spanish Flyer

You don't mention if you're running stock headers w/crossover or true duals.  Even on the "stacked" pipes that you're talking about, the factory pipes have a crossover tube.  Approximately 65% of the exhaust goes out of the pipe that is originating off of the front cylinder, so the temp differences and amount of exhaust coming out of your "rear" cylinder pipe will be less and cooler...that's perfectly normal.  If you're running true duals, your rear temps, due to airflow (rear cylinder does not get as much airflow across the fins as the front does) should be higher then the front. 

   

[Spanish Flyer]

Thanks for the replies guys,

I thought you would have watched the video I included, where the pipes are clearly shown. Anyway they are the slash down type and my bike is not one of your baggers, but on the contrary, the very slim Softail Springer 2008 CVO. The pipes are the standard with a slight modification (perforated muffler, so they are almost open pipes). Someone mentioned the by-pass between both headers, but that would surely affect both exhaust outlets, not only the top one.....

Anyone with Damaged ACR's might be able to throw some light here; never the less any help will be welcome.

And please check the video...     http://es.
 Thanks,
Spanish Flyer

[porthole]

I thought you would have watched the video I included, where the pipes are clearly shown.
bike is not one of your baggers, but on the contrary, the very slim Softail Springer 2008 CVO.

http://es.

Less then 40 posts and you are trying to dis the people that can help you more then any dealer.

So I watched your video after the 2nd link was posted, it is not real clear as to the pipes, but you do seem to have a crossover pipe which will change the amount of exhaust out of each pipe, one cylinder is always behind the other in the firing order so one cylinder is always being "scavenged".

You may have a very slim springer, but I have a fat bagger with a 103

[grc]

Spanish Flyer,

The bagger pipes, as noted by some of the others, have an obvious difference in flow from left to right due to the crossover design.  The difference on the softail's and dyna's is less pronounced, but in my experience there is a difference as long as you have the stock exhaust with the crossover tube.  The only way I know of to prove it to yourself will require some disassembly, to separate the pipes at the crossover and then temporarily plug the crossover tube.  Once that is done the volume at the mufflers should be equal. 

Most of the ACR failures I've read about have involved the failure of the ACR to open, resulting in hard starting.  If they were leaking you should be able to hear the high pressure escaping, similar to a blown head gasket or loose spark plug.  If it was leaking enough to affect exhaust volume, it would run very rough at low speeds.  From your video I didn't hear any evidence of that.

Jerry

[sportygordy]

to stop signal to the ACR remove the wire at pin 15 on the ECM connector

[hayman7712]

I had rear ACR failure in my first 07 SERK.  It would backfire and just all around ran like crap.  The wires were fried to it also.  So they replaced the ACR.  The Tech told me when the ACR stays open its like running on one cylinder.  After they fixed all that stuff, we found out the flywheel was bad.  So now I'm on my 2nd 07 SERK.  I haven't had any problems with this one.  (knock on wood) I have had chrome peeling problem though.  They're taking care of that.  Dean.

[sadunbar]

to stop signal to the ACR remove the wire at pin 15 on the ECM connector

The ACR wire is purple...you can unplug it from your ecm connector quite easily...this will disable your ACR's.  But if one is stuck open, this would not correct that condition.

To check whether or not your ACR is failed open, you can do a compression test...but as others have said, if an ACR is failed open you would hear air escaping through it.

And, as others have said, unless you are running a true dual exhaust - with no crossover pipe, you will have a different exhaust flow between the two pipes.

I watched your video and did not see a clear picture of both of your cylinder heads to know exactly what configuration exhaust you are running.

If your only symptom of a problem is more exhaust and heat coming from one pipe as compared to the other, I think you are fine and do not have a problem.

good luck and safe riding..
 

[RedDevil]

Thanks for the replies guys,

I thought you would have watched the video I included, where the pipes are clearly shown. Anyway they are the slash down type and my bike is not one of your baggers, but on the contrary, the very slim Softail Springer 2008 CVO. The pipes are the standard with a slight modification (perforated muffler, so they are almost open pipes). Someone mentioned the by-pass between both headers, but that would surely affect both exhaust outlets, not only the top one.....

Anyone with Damaged ACR's might be able to throw some light here; never the less any help will be welcome.

And please check the video...     http://es.
 Thanks,
Spanish Flyer

El Flyo, After watching your video, your "thin Springer" doesn't sound and different then any other thin Springer I've heard.  Your bike started normal and it idles fine, so it's not an ACR stuck open.  If all you've done to your stock exhaust is perforated the baffles, then what you are experiencing is normal exhaust flow out of the pipes.  You should be out riding it instead of trying to fix something that isn't broken.  If you still think there's something wrong, take it back to the dealer, that's what your warranty's for.

   

[BIGDOG]

Thanks for the replies guys,

I thought you would have watched the video I included, where the pipes are clearly shown. Anyway they are the slash down type and my bike is not one of your baggers, but on the contrary, the very slim Softail Springer 2008 CVO. The pipes are the standard with a slight modification (perforated muffler, so they are almost open pipes). Someone mentioned the by-pass between both headers, but that would surely affect both exhaust outlets, not only the top one.....

Anyone with Damaged ACR's might be able to throw some light here; never the less any help will be welcome.

And please check the video...     http://es.
 Thanks,
Spanish Flyer

Dude way harsh so soon.    If you still think you have a problem , get a remote inferred thermometer and read the temp at each head. If that's not doable take it to the dealer. Good luck and be nice.

[sadunbar]

English is not the first language for Spanish Flyer  - but he is trying to communicate with us in English, so I wouldn't read to much into the wording of his posts.  I think the intent of his question is fairly clear and I believe think he meant any offense with his phrasing...  just saying...

[RedDevil]

English is not the first language for Spanish Flyer  - but he is trying to communicate with us in English, so I wouldn't read to much into the wording of his posts.  I think the intent of his question is fairly clear and I believe think he meant any offense with his phrasing...  just saying...

Sadunbar,  I can't speak for the rest, but I certainly didn't take any offense to his wording.  How did you come to the conclusion that English is not his first language? I don't see anything in his profile to ally that.  I thought, for the most part his posts were done in very good English...

   

[sadunbar]

Sadunbar,  I can't speak for the rest, but I certainly didn't take any offense to his wording.  How did you come to the conclusion that English is not his first language? I don't see anything in his profile to ally that.  I thought, for the most part his posts were done in very good English...

   

I recall from some of his earlier posts he makes note of his "European model" and I also believe he makes reference to his home in Spain.  That doesn't necessarily mean his first language is not English - I just thought from some of the responses that some of his wording may have been misinterpreted...