Hard to describe, and I think its only on the newer 96" motors (?). When the engine starts, there is a noise, often described as a bang. I alway thought it was just the engine initial firing, sort of a Harley thing. Untill a buddy got the SE comp on his bike. The "initial bang" disappeared. The factory comp is so weak, is doesn't really work. However, the real different is the smoothness in take off with the new one....with it the compensator is actually doing what it is intended to do.

The install challenge is that the factory comp/alternator won't slide out of the inner primary, beause the clearance is too tight by maybe 10/1000" or so (just a guess). Most likely just another factory screw up. You can either take off the starter, and the inner primary, or just grind the outer by the 10/1000 or so. The area you are grinding on is very thick, no issue there. Takes 20 minutes with a high speed grinder.

 

I was guessing that the bang sound came from the flimsy compensator bottoming out. The stock one is far too soft, and it wouldn't take much to bottom it out.
Kick back could do it, in my opinion.

 

The bang is caused from the comp cam flattening the spring pack against the rotor. Metal to metal impact. Starting direction gives it a wind up in one direction and when the engine fires it rapidly rotates (rebounds)the other direction and bottoms the spring pack out with brutal force.
Ron

 

I did not notice any difference between the stock comp and the SE comp, other than the start up clunk is gone, which is why I changed it. I will also be installing a 103 kit this winter, and have SE255 cams, so the se comp should be better for this combination.

I did not have to remove the primary or grind clearance to remove and install the new one. It was very close but did go together. 07 Ultra,

 

There's a little lip on the inside of the inner primary. On some bikes this
prevents the rotor from sliding out. Some guys have no problem, some
have to do a bit of grinding. Mine made contact between 6 and 9. Sorry
I did mine about a week ago, so no pictures.

Boxs

 

I really appreciate all the information and comments. I have a couple of additional questions:

1) Looks like the OEM compensator bolt head uses a ¾” socket, is the SE compensator bolt head also ¾”?
2) I’ve read that it is important to be careful with the springs in the SE compensator during installation or have potential for vibration? Since I haven’t received the SE compensator yet, what’s this about?
3) I’m planning on making a locking tool, looks like a simple flat bar?
4) I’m going to try to do this w/o grinding the inner primary, after loosening the inner primary bolts, how much can I move the inner primary w/o damaging seals?
5) Any other tips or tricks?

Thanks again for all the help.

 

PM sent.

 

I only rode mine today from the service door to my trailer and from my trailer to my garage but it seemed quieter. I didn't even notice the clunk going into 1st gear. Do it yourself if you can, my dealer said they charge 5 hours labor. Mine was covered under warranty, $142.83 for the upgrade.

 

I took a different route and installed the EVO engine sprocket that eliminates the comp all together. The engine starts almost instantly after hitting the starter now. It used to turn over a couple times first. No primary noise when starting or riding. Plus now it has a lower gear which improves acceleration some. I am very happy with the results. The higher revs dont seem to be enough to bother me at highway speeds. Just over 3000 rpm at 70. Before was about 2800 at 70.

Also didnt have to remove inner primary or do any grinding.

 

When I removed my old comp sprocket (24,000 miles) it actually had grooves worn in it where the cam lobes were rubbing back and forth. That has to be hard on something in the drive train, all that back and forth shock. The grooves are worn stop to stop (where the spring pack bottoms out). I would definately recommend changing the stock comp for something better.