has anyone had a second compensator failure?
#11
Join Date: Apr 2009
Location: Al Bu Ker Key, New Mexico
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root cause of the crank bang problem is compression build up in the heads. the compensator upgrade just helped mitigate the issue. but it never really fixed the problem. to explain the root cause better think about what happens when you start a push cord lawn mower. the mower is almost impossible to start if the piston is just before top dead center. If you detect that it is just before TDC, you pull the cord a bit to get the piston past TDC. what 's happening here is the compression buildup makes it almost impossible for you to crank the engine. if you try to crank a lawn mower that is just before tdc, what happens, it yanks you back. Same issue with you bike. when you shut your bike off, a lot of times the engine will stop with pistons in the position approaching TDC. when the starter trys to engage and start the engine, the compression springs the crank back causing the starter gears to slip....the bang grind. replacing the compensator to the new SE comp, just gave you more spring preload to help prevent the crank spring back. the root cause is the compression in the heads. as a bike ages, carbon accumaltes and incresases this compression. the fix is compression release.
#12
If what speakerfritz said is true, and one must assume he knows what his talking about, it is just another example that Harley Davidson doesn't fix known problems. I just don't get it, why don't they fix these issues if a simple compression release would fix the issues with compensations going on the blink. If I hadn't have had the extended warranty, this would have cost me a grand or more to correct. When people ask if a extended warranty is worth it....best read these post on compensator's. Dam, it just pisses me off sometimes.
#13
Join Date: Dec 2007
Location: Lake City, Florida (Native)
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I'm on my 5th comp. 4th s/e. Original upgraded at 21k. That one was replaced 4k later in conjunction with IPB, main shaft bearing and clutch. That one lasted a long as the test ride. Number 4 was in for 1k. My 5th was installed with a new clutch spring. 30k now and all is well. Also, just bought the extended warranty!
Smart Move, within 8 months my Extended Warranty paid for itself .. Part of it being a free SE Compensator ..
#14
If what speakerfritz said is true, and one must assume he knows what his talking about, it is just another example that Harley Davidson doesn't fix known problems. I just don't get it, why don't they fix these issues if a simple compression release would fix the issues with compensations going on the blink. If I hadn't have had the extended warranty, this would have cost me a grand or more to correct. When people ask if a extended warranty is worth it....best read these post on compensator's. Dam, it just pisses me off sometimes.
Last edited by dickey; 04-03-2012 at 02:35 PM.
#15
So, not sure what your complaint is.
BTW, I am sure the explanation given about TDC is good information at startup time, but a weak compensator will also be responsible for drive line lash. I can hear my compensator banging when I get off and on the throttle too. The stock compensator in my '09 is simply under-engineered and cannot take any kind of hard riding and I think should be a required upgrade with any upgrade that increases horsepower or torque in the 96. It makes me wonder if the design is simply an artifact from the 88 days that wasn't properly matched to the torque in the 96.
#17
Just thinking out loud here, but did you ever stop to think that they keep replacing these compensators when that is not what is making the noise?? That is a pretty sweet revenue cow when you think about all the twin cams out there that backfire a little when they are hot.
#18
root cause of the crank bang problem is compression build up in the heads. the compensator upgrade just helped mitigate the issue. but it never really fixed the problem. to explain the root cause better think about what happens when you start a push cord lawn mower. the mower is almost impossible to start if the piston is just before top dead center. If you detect that it is just before TDC, you pull the cord a bit to get the piston past TDC. what 's happening here is the compression buildup makes it almost impossible for you to crank the engine. if you try to crank a lawn mower that is just before tdc, what happens, it yanks you back. Same issue with you bike. when you shut your bike off, a lot of times the engine will stop with pistons in the position approaching TDC. when the starter trys to engage and start the engine, the compression springs the crank back causing the starter gears to slip....the bang grind. replacing the compensator to the new SE comp, just gave you more spring preload to help prevent the crank spring back. the root cause is the compression in the heads. as a bike ages, carbon accumaltes and incresases this compression. the fix is compression release.
#20
Pretty sure that beginning with 2012, all of the bikes equipped with the 103 also come with automatic compression releases, as well as the SE compensator and an oil cooler. All in response to known issues.
So, not sure what your complaint is.
BTW, I am sure the explanation given about TDC is good information at startup time, but a weak compensator will also be responsible for drive line lash. I can hear my compensator banging when I get off and on the throttle too. The stock compensator in my '09 is simply under-engineered and cannot take any kind of hard riding and I think should be a required upgrade with any upgrade that increases horsepower or torque in the 96. It makes me wonder if the design is simply an artifact from the 88 days that wasn't properly matched to the torque in the 96.
So, not sure what your complaint is.
BTW, I am sure the explanation given about TDC is good information at startup time, but a weak compensator will also be responsible for drive line lash. I can hear my compensator banging when I get off and on the throttle too. The stock compensator in my '09 is simply under-engineered and cannot take any kind of hard riding and I think should be a required upgrade with any upgrade that increases horsepower or torque in the 96. It makes me wonder if the design is simply an artifact from the 88 days that wasn't properly matched to the torque in the 96.
And, installing compression releases is a MAJOR deal. I just did it and it took me about 8 hours total and three weeks at the machine shop. Harley would not stand behind these issues.
I will NEVER buy another new Harley again, they don't deserve my business.