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[1abastarsmda]

As many of you already know, my starter went in Eureka Springs and I had it replaced.  I'm still having problems starting the bike though.  I get some awful sounds and get big puffs of black smoke backfiring from somewhere on the engine.  I'm pretty certain that I'm going to need another starter again if I don't get to the root of the problem soon.  I'm making a guess that it may have something to do with the ACR's not functioning properly.  I stopped at a dealer in Columbia, SC and the technician there agreed that he thought this was my problem.  He told me he thought I could make it for a little while before I would have the starter go again, since they weren't able to do the job that day and I didn't want to waste another day of my trip.

My elementary understanding of the ACR's is that they are a pressure relief that opens during starting to relieve some compression pressure and close back up right away.  I'm assuming that if they don't open, that pressure is being relieved elsewhere and thus the puffs of black smoke coming from some other undetermined location.  Do the ACR's get blocked or clogged or in some other way kept from functioning on every start?  Can they be functioning on the occasions when the bike actually fires right up and not functioning on the times it doesn't?  I probably won't get my bike into the shop until sometime next week and I'd like to have a little more understanding of their function before I go to the shop and tell them what I think the problem is.  Any help out there would be appreciated.

BTW, the service manager told me he checked to make sure they were not disabled a few weeks back.

[Twolanerider]

You generally nailed it.  Compression release is, as the name suggests, a pressure relief.  Even though the 110 aren't terribly high compression engines the pressures built suggest their benefit.

Prior to the 110s other manufacturers used automatic compression releases; generally without issue.  Harley, as an accessory after the fact, had always offered manual releases.  Basically a push button pop-off valve that reset under pressure.

The automatic (the A in ACR) variant are electrically actuated.  They have given problems.  Compression releases generally, though this is often not done, are a maintenance item.  They occasionally need to removed and cleaned as they can get carbon loaded.

That's easier to do on the manual releases on older heads.  The physical location they exist on your ACR's makes it more of a chore.  Their biggest problem so far has been electrical though.  The routing of the harnesses that fire them has allowed damage to some of those harnesses.

Hope any of that helped.

[1abastarsmda]

You generally nailed it.  Compression release is, as the name suggests, a pressure relief.  Even though the 110 aren't terribly high compression engines the pressures built suggest their benefit.

Prior to the 110s other manufacturers used automatic compression releases; generally without issue.  Harley, as an accessory after the fact, had always offered manual releases.  Basically a push button pop-off valve that reset under pressure.

The automatic (the A in ACR) variant are electrically actuated.  They have given problems.  Compression releases generally, though this is often not done, are a maintenance item.  They occasionally need to removed and cleaned as they can get carbon loaded.

That's easier to do on the manual releases on older heads.  The physical location they exist on your ACR's makes it more of a chore.  Their biggest problem so far has been electrical though.  The routing of the harnesses that fire them has allowed damage to some of those harnesses.

Hope any of that helped.

Thanks Don.  So there's either an electrical problem causing them not to work or they are carbon loaded and need cleaned.  My understanding of the location of them is such that this isn't a quick, easy job to get to them and then I can only hope they don't damage anything else in the process...since I haven't had a lot of luck with getting my bike back after repairs undamaged.  I'm also guessing that if replacement is in order, if they don't have them in stock, they could always raid an 07/08 enhancement kit and replace them later.  I'll take it to the shop after Memorial Day and see where that gets me.

[skreminegul07]

Going back a year or so, one version of the ECM software update for some fix from HD had the ACRs disabled by default.  If you have a SERT and the S/W on your laptop, you can hook it up and check it.  It is easily turned on from the SERT S/W without affecting the tuned map.

[LarryB]

yours sounds like a cold start problem to me. Too Rich?

[1abastarsmda]

yours sounds like a cold start problem to me. Too Rich?

It happens cold or hot, but I have thought about that.  Maybe I'll pull a plug and look at it.  But I have to go get ready to leave for a ride to Maryland now.

[Rooster]

Sorry to hear, I thought the ACR problems were solved with the 07,08's in the "FIX". Oh yea I forgot the fix didn't work as mine is back in the shop. Hope there is a fairly simple answer to your issue. Over all I have to say it seems th e 09's are having very few issues.

[Gone Fishin']

Your bike should be still under warranty. So why not let the dealer worry about all this? It could be an electrical failure or mechanical. With the ACR's being a source of trouble for many '08 bikes, I am sure that you will get them replaced by warranty anyway. That would take of either problem, in my mind. The puffing you experience is obviously exhaust going the wrong way and coming out through the air filter.

Ride safely,
Louis

[LarryB]

It happens cold or hot, but I have thought about that.  Maybe I'll pull a plug and look at it.  But I have to go get ready to leave for a ride to Maryland now.

Maryland, man , there's no flies on you.

[grc]

Still sounds like an ACR problem to me.  If you get lucky and the pistons are on the exhaust or intake strokes when you hit the start button, the starter can probably attain a fast enough first spin to fire the engine normally.  If it doesn't fire immediately, or if the pistons are on the compression stroke, the starter hits instant resistance and may not spin quickly enough to fire up immediately, leading to kickback and a puff of smoke.

It would have been nice if H-D had located the ACR's where you could actually see and access them, but that's like lots of other things that would have been nice if H-D ever got their heads out of their collective rear ends.  A competent shop should be able to quickly diagnose and rectify this issue.  If you can't find a competent shop and get tired of all the BS, you might want to consider swapping cams to something with a little overlap to reduce that cranking pressure and then eliminate the ACR's.  You wouldn't need them if Harley hadn't gone with the 255 cams, since static compression is only around 9:1.

JMHO.

Jerry

[guppytrash]

I was having the same problem.  I would bet you have the exact same problem I had.  YOUR ACR's ARE OFF!
If you plug in to a super tuner you better make sure the last thing you do before you unplug is make sure the ACR's are enabled.
The Tech who worked on mine turned them "on" for me, then we made some adjustments and sure enough they were turned off again.

Make note to self...Self before hitting exit on ANY super tuner activity check the ACR's enabled.

HD Tech said the Moco sent a bulletin addressing the ACR's turning off when a Super tuner is hooked up.

You probably hear your starter clutch disengage due to it trying to protect itself.  Not a pleasant sound, but it is doing what it is supposed too.
It simply can't handle the compression.   
 

[Black Diamond]

I was having the same problem.  I would bet you have the exact same problem I had.  YOUR ACR's ARE OFF!
If you plug in to a super tuner you better make sure the last thing you do before you unplug is make sure the ACR's are enabled.
The Tech who worked on mine turned them "on" for me, then we made some adjustments and sure enough they were turned off again.

Make note to self...Self before hitting exit on ANY super tuner activity check the ACR's enabled.

HD Tech said the Moco sent a bulletin addressing the ACR's turning off when a Super tuner is hooked up.

You probably hear your starter clutch disengage due to it trying to protect itself.  Not a pleasant sound, but it is doing what it is supposed too.
It simply can't handle the compression.  
 

If it's doing the same as it did on our E. S. ride, I agree with GP. That sure is how it was presenting when we were trying to get her restarted! Good luck.

JW

[Classic45]

I experience exactly the same problems with my CUSE3. I'm waiting for the "Upgrade" to be performed, including some work on the "ACR".

My aft cylinder started to leak after 16 000 km.

[1abastarsmda]

My bike is done and they replaced the ACR's.  I haven't picked it up yet, but I sure do hope that fixed the problem.  I'm hoping the shop didn't just replace them because I told them I thought that was the problem.  Hopefully they actually checked things out and determined on their own that this was the fix.

[1abastarsmda]

I went for a nice ride yesterday and with many starts, it fired up every time.  When I picked it up at the dealer, I was a bit worried, as it was turning over like a car trying to start, and wasn't starting.  Eventually, after the 4th try it started and since then it's been starting on the first try.  Going for another good ride today, and I'll be convinced if it continues on working properly today.  I thought it was okay after getting the new starter, but that only lasted for about a day.

How do I know if they actually replaced the ACR's?  How do I know that they didn't just check and find out that they were deactivated and that was the problem all along?  I guess I am a true skeptic.