compensator assembled

Harley Drive Train Compensator Blues

Posted on 23. Jul, 2013 by in Panman's Garage

Riding cross country, I always seem to be especially tuned to hearing unusual noises from my bike. A tick here, a clunk there. But when you put them all together, you finally realize that you have been riding with the Harley drive train compensator blues.

It started out as a loud ticking noise. This went on for a couple of years, no one really taking too much notice. After all, Harley-Davidson is well known for having a primary drive system that sounds like a freight train is passing, right? But it didn’t stop there. worn compensator Before long, it became harder and harder to start, especially when warm. Loud belches of unburned fuel spewing from the fuel body should have been a good indication of something wrong. But not a single mechanic diagnosed the problem.

One day I came across a posting on The gentleman described his hard starting and knocking noises, and then gave the answer to the problem. A bad or worn compensator.

primary The compensator is the drive mechanism located on the end of the engine main shaft, transferring the engine rotation by way of the primary chain to the clutch basket and transmission. It provides for a smooth transfer of the power to the transmission and takes up any shocks from the transmission to the engine.

Knowing that I was nearing my peak riding season (daily rider, but summer I take longer trips), I decided that I would just replace it with a Screaming Eagle compensator. After a little research, I decided on the Screaming Eagle because it is suppose to be 7x stronger than the stock compensator. This would not surprise me at all!

The Screaming Eagle compensator came with all the parts necessay for installation, and clear instructions.

Stock Harley compensator

Stock Harley compensator

Going through the parts and instructions, it became clear that I would need to take off both the outer primary cover and the inner primary cover in order to replace the stator magnet that comes with the kit. Cute how Harley started putting a ridge inside the inner primary that prevents you from removing the stator magnet without first removing the inner primary cover!

As it turned out, it was a good thing that I did need to remove the inner primary cover. In order to do so, I had to remove the clutch basket. That is where I found an unexpected problem.

clutch basket A couple of years ago, I replaced the main shaft bearing to my transmission. When I did this, I found the belt hub splines were all delaminating. As it was told to me, A Harley vendor failed to properly heat treat a large batch of these hubs. Harley put out a service bulletin to the techs, but the general public was pretty much on their own.

Well turns out, this same vendor also made the clutch basket for Harley. And you guessed it, it is not properly delaminated splines heat treated either. What I found was the splines inside the clutch basket were also delaminating. Pieces of splines were falling out of the clutch basket all over the ground. Just wonderful!

After another parts run to the local dealer, I was able to get a replacement clutch basket for replacement. Like I said, good thing I found it. It would have been a bear to find the problem as I crossed over the Rockies on my way to Sturgis!

Screaming Eagle compensator Clutch basket back together, I installed the springs and sprocket to the compensator. Just looking at the compensator tells you it is far more heavy duty. It is heavier, with huge plate springs and a large spline gear adaptor that slides over the main shaft. The stock compensator has just a few large splines that the chain gear rides on. On the stock unit, these splines were badly damaged, allowing the compensator to rock back and forth. The Screaming Eagle compensator has a much superior spline shaft arrangement that I believe will eliminate this problem.

Aside from running for parts, the total job was done in less that 3 hours. Not to bad!! And then off to road test. compensator assembled

The first thing I noticed was the bike was once again smooth at low speed. No more jerking that had to be controlled by feathering the clutch. As I rolled down the boulevard, the power transfer seemed a lot smoother. But when I started onto the freeway, that is when it showed it’s strength. Power transfer was immediate and smooth. Gone were the sounds of the familiar freight train. And shifting, especially down shifting, was a lot smoother and without the customary “clunk”.

Starting while hot was now no longer a problem. She cranked over easily, and no longer back fires when starting. I am relieved that problem is resolved!

If you are experiencing loud noises from your primary, hard starting when hot, and strange vibrations or hard shifting, I highly recommend that you take a good look at your compensator. And I believe that you will eliminate the Harley Drive Train Compensator Blues with a Screaming Eagle compensator.


Join the forum discussion on this post - (1) Posts

Tags: , , ,

8 Responses to “Harley Drive Train Compensator Blues”

  1. Martin Westerlink

    23. Jul, 2013


  2. Jon Lewis

    23. Jul, 2013

    This will be at the top of my Mods this winter in the down time. Thank you for posting your problems and why they happened. Where is quality control at HD? geesh.

  3. Steve Dennis

    25. Jul, 2013

    Damn Coach,wish I was out there with you. Don’t think John is going to make it ether. Wil you send some pics of the camp ground?

  4. Hd Openroad

    25. Jul, 2013

    Steve, you and Jackass will be missed! Going to try our hand at Glencoe, check out some name entertainment this year. Drop some pics as they happen.

  5. Steve Dennis

    26. Jul, 2013

    Photos would be great. I’ve stayed there for several years,it is one partying place. Gonna miss seeing you Bro. Have you left yet?

  6. Hd Openroad

    26. Jul, 2013

    Leavin’ Sunday morning.

  7. Danny Q. Stewart

    28. Jul, 2013

    Been havin issues with the bike burpin up threw the air cleaner when hot and try to restart for awhile now had the dealer look at it a few times to the same tune of we cant find anything I have even posted about it. Thought it couuld be a bad tune but it did it when it was stock did it when I did the stage 1 and got tuned and still does it now that I have done stage 2 and tuned but more and more is it not only burpin up threw the air cleaner the starter is startin to slip and grind every 4th or 5th time I try to start it when the bike is good and warm. I remember reading something in AIM a few month back in the hog help line..So I Got the old issues out and sure enough they described to a T what my bike is doing caused by a week compensator trashing the starter clutch drive gear and ring gear on the clutch basket. I got 2 more months on my waranty and the dealer said bring it in they admit it has been a issue but they said they dont know if it the starter or the compestaor. How do I convince them they need to replace all of it show them the issue of AIM they will prob think thats what put it in my head. Then if they do that there prob gonna use a stock compensator I could then replace it with a sreamin eagle but heard those are having issues with not gettin enough oil also. Is there no good cure?

  8. Steve Dennis

    29. Jul, 2013

    Ride safe,my Brother.

Leave a Reply