To Compensate or Not?

[Bob1320]

After owning two 1200 Sportsters, I moved up to a 2006 Dyna Lowrider with only 3500 miles on it.  My Sportsters were as smooth on deceleration as they were on acceleration.  The Dyna vibrates, shakes, and shudders on deceleration in every gear from 2500 RPM to idle.  It's not a normal Harley shake or vibration at idle which I love.  It actually vibrates the fuel pump, sender unit, and other parts inside the tank!!! 

I replaced the motor mounts, did the alignment with a digital inclino-meter, tuned the motor with a PCIII, and replaced the automatic chain tensioner.  Nothing helped, so I disassembled the entire primary and checked the inner primary bearing, clutch bearing, compensator bolt, sprocket alignment, and sprocket shaft/mainshaft runout.  The crank has .004 runout and the mainshaft has .003 runout.  While not great, this is as good as it gets from MOCO.  While examining the compensator assembly, I noticed that the sprocket gear wobbles on the extension.  The spring pack feels weak and has almost no preload.  Since the Sportster does not use a compensator, I've concluded that this is the cause of the problem.  I've considered going to an enclosed belt drive to eliminate the compensator and heavy chain assembly, but there are none available yet for 2006 and up.  BDL says maybe next year?

I won't even ride this bike the way it is, it's beautiful, but rides like sh*t!  I can easily remove the spring pack and the compensator cam and TIG weld the extension to the sprocket to create my own 34 tooth sprocket and lose the compensator.  I don't know why Harley feels that the 1200 Sportster doesn't need a compensator and the 1450 does, unless the crankshaft can't handle the stroke.  I don't beat on my bikes at all.  I don't want to wait for someone to make an enclosed belt drive and don't want a noisy, chattering dry clutch either. (Picky aren't I?)

Does anyone know if the new SE Compensator will work on the 2006 Dyna?  The book says 2007 and up only, but unless the sprocket shaft on the crank is different, it should work.  But, I don't even know if that will cure the problem.  So, I'm asking for some knowledgeable opinions.  Should I compensate or not compensate?     

[dakota224]

Bad crank.  to much run-out.

[Bob1320]

If it was the crank, the vibration would occur on acceleration as well as deceleration....

[tdrglide]

A friend has the same problem on his Dyna. Bad vibration on decell only from about 2600 rpm. Acell is smooth. I'm guessing on the rpms, has no tach. I put I.E.D's on the O2 sensors and rode it around for 500 mi. or so and it seemed to get somewhat better. We didn't measure anything

[Bob1320]

My O2 have been eliminated with the PCIII as well...... no change.

[tdrglide]

Only seemed to get somewhat better, as in a little. If it was mine I would not be happy. I would like to know what the fix turns out to be.

[hdpegscraper]

Bob...., Did you remove the compensator spring/ rotor assembly and inspect it? The early 06 ones are a 2 piece unit, bolted together from the stator side. These bolts can come loose and then sheer off, making for a bad day. The later replacement part is welded together making it a one piece, not a two part unit.  You may want to see which one you have in there.

[drhooligan]

Are there any ill effects on the crankshaft or bearings from running an engine sprocket with no compensator?

[Bob1320]

I'd like to know the same thing.  Sportsters don't use a compensator and have no problems and my Sportster run very smooth.  Evolution Industries makes a 30 tooth sprocket that eliminates the compensator on 2006 and up Dynas to change the gear ratio.  They claim it's their biggest seller, so there is a lot of TC's out there with no compensator.  I suppose I'll just weld it up and see what happens.

[se]

you have the "A" motor which has a little more vibration then the softtails do well a lot more at times. its not the compensator its the flywhheels and crank assembly.  not sayin they are bad but thats what causes it to vibrate a little more. The :B: motor has balancer  that make it smooth. now you stated you are running a p.c ok did you dyno tune the bike or just going off the seat of the pants. theres a big diffrence here.  get yourself on the dyno aand tune the bike that will smooth the decel vibration out and also make the motor run way better.
you cannot start looking at other issues until you get the tune streight.
after the tune is streight then worry about the vibration it may vibrate because the tune is off.  

[se]

a guy on another forum welded his didnt hear much about what hapened. .. i dont know the compensator is there for a reason mine is still in and i have a lot more power then you do and my bike vibrates very little and my balancers are removed crank is lightned and balanced tho......

[Bob1320]

you have the "A" motor which has a little more vibration then the softtails do well a lot more at times. its not the compensator its the flywhheels and crank assembly.  not sayin they are bad but thats what causes it to vibrate a little more. The :B: motor has balancer  that make it smooth. now you stated you are running a p.c ok did you dyno tune the bike or just going off the seat of the pants. theres a big diffrence here.  get yourself on the dyno aand tune the bike that will smooth the decel vibration out and also make the motor run way better.
you cannot start looking at other issues until you get the tune streight.
after the tune is streight then worry about the vibration it may vibrate because the tune is off.  

The bike has Vance and Hines Big Shots, Quiet Baffles, and SE Air Cleaner.  The o2 sensors are bypassed with the appropriate resistance.  I started with a zero map to see if it would run any better with the stock Stage 1 flash.  Then I tried each of the maps provided by Dynojet for my bike as modified.  All the Dynojet maps help with popping on decel and performance, but have no effect on the vibation on deceleration.  From what I understand, the injectors are turned off on decel, is that correct?

[drhooligan]

I'd like to know the same thing.  Sportsters don't use a compensator and have no problems and my Sportster run very smooth.  Evolution Industries makes a 30 tooth sprocket that eliminates the compensator on 2006 and up Dynas to change the gear ratio.  They claim it's their biggest seller, so there is a lot of TC's out there with no compensator.  I suppose I'll just weld it up and see what happens.

That Evolution Industries 30T is exactly what I am considering, just wodering if it is safe to use on an '07.

[drhooligan]

We need more feedback here.

[tireater]

I have the 30t with no compensator on my 06 St Bob...So far so good...

[Lamar07]

same here 07 flhtcu no problem

[drhooligan]

I have the 30t with no compensator on my 06 St Bob...So far so good...

Good, glad to hear that. I needed to be kinda talked into it. How do you like it? Noticeably more zap out of the hole?  Thanks.

[tireater]

With 107 ft lbs... the bike now tries to leave without you...Scary fast and quick enough to get you in big trouble...I like it 

[Coyote]

I'd like to know the same thing.  Sportsters don't use a compensator and have no problems and my Sportster run very smooth.  Evolution Industries makes a 30 tooth sprocket that eliminates the compensator on 2006 and up Dynas to change the gear ratio.  They claim it's their biggest seller, so there is a lot of TC's out there with no compensator.  I suppose I'll just weld it up and see what happens.

That Evolution Industries 30T is exactly what I am considering, just wodering if it is safe to use on an '07.

I had one in my 07 SEUC. Took it off and went back to stock, mostly because my builder wanted it stock. I have one with the chain I sell for half price plus shipping. It was on the bike less than 10k miles.

[drhooligan]

I'd like to know the same thing.  Sportsters don't use a compensator and have no problems and my Sportster run very smooth.  Evolution Industries makes a 30 tooth sprocket that eliminates the compensator on 2006 and up Dynas to change the gear ratio.  They claim it's their biggest seller, so there is a lot of TC's out there with no compensator.  I suppose I'll just weld it up and see what happens.

That Evolution Industries 30T is exactly what I am considering, just wodering if it is safe to use on an '07.

I had one in my 07 SEUC. Took it off and went back to stock, mostly because my builder wanted it stock. I have one with the chain I sell for half price plus shipping. It was on the bike less than 10k miles.

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