V-Twin Forum banner

Primary/compensator Sounds

7.6K views 12 replies 5 participants last post by  herringdan  
#1 ·
Twice in the past two months I've pulled my entire primary apart, for different reasons, and put it back together. Both times I fired the bike up, rode it for 45 min or so and parked it. It ran fine. The second time though, I made it about 2 blocks and started hearing a scraping scuffing sound coming from the front of the primary. Some I've heard describe it as rocks bouncing around inside which I can compare my sounds too as well. I oiled up the stator and cover and all parts before assembling and assembled it correctly. I don't understand this and need help. What do you guys think? The compensator sprocket was fine as well as everything else for that matter inside the primary case, these sounds started after I took it apart. Typical... Any advice or thoughts? Thanks, Glenn
 
#2 ·
Best take it apart again and have a look see, maybe a piece of magnet off rotor? A piece of something is making the noise! What bike?
 
#3 ·
the rocks sound may be the chain flapping around. Maybe the tensioner loosened up. Could be an easy fix. Look through the inspection cover first.

rkc
 
#4 ·
It's a 92 heritage classic. It's not the chain because this happened the first time too and it was tight. I read somewhere else about a similar sound coming from the compensator but cannot remember where. I'm not sure why the sound is being made as there aren't any bearings up front there or anything so I'm stumped.. Any other thoughts?
 
#5 ·
As I'm doing more research I finding this is a very common problem in older bikes. I guess the compensator sprocket cover has springs inside that compress under load. Over time they wear out and that is the reason the sound is being made. Anyways it's a $25 dollar cover with new springs. I'm gonna order one and put it in. Hopefully this solves the problem. If anyone else has more advice please share. Thanks alot.
 
#6 ·
Check for excessive wear on the sliding cam and sprocket where they contact each other. Mine was making a loud snapping/clicking noise and both pieces were polished smooth from rocking back and forth. I think the worn cover was also the reason the spring in my HB125 chain tensioner broke.

The springs are called Belville springs, there are 4 stacked inside the cover on my era bike, not sure about yours. If your bike is basically stock motor-wise, you should be good for another 20 years. Can't complain about that for what is obviously a wear item.

From my experience, the design doesn't like 100+ HP/TQ. I got the bike at 8 years old and did most of my mods in the first year I had it. Had two good trouble free years, and have been chasing one issue after another with the primary drive for the last year and a half. I guess its cheaper than buying a new bike.
 
#7 ·
I'll check those parts that you mentioned. My bike is a 92 so it is 20 years old, and once I pulled that cover off the compensator, those springs probably stretched and aren't compressing properly anymore. Either way its a $25 part and I might as well give it a shot before buying the more expensive pieces to the puzzle.
 
#8 ·
I'm looking at the parts book for mine and all the compensator components have a -91 or older number, so yours is the same as mine. That's about $160 for cover with springs (40384-91) at the dealer for genuine HD parts. I got the cheapest version I could from the company with the museum, $36 shipped to my door. It's doing its job for now, but who knows for how long. They also had a $75 version. I would have bought it from my buddy, the indy, out of the Drag catalog, but I couldn't find the cover by itself and since I had already replaced the cam and sprocket, I didn't want a whole new one.

If you have access to some old parts, you could take one spring from an old cover and add it to yours as a shim to tighten things up some. Might give some more life to the old compensator.
 
#9 ·
http://www.jpcycles.com/product/601-366 Thats the part I ordered from JP Cycles. It says its the cover with springs, I'm hoping this is correct. I've read that the stock HD ones are junk and most people go with the after market SE or ones off jpcycles. It will be here in a few days and I'm hoping this does the trick. I'm still open to any other advice anyone has. Thanks, Glenn.
 
#11 ·
No, I ordered the same one you did. Looks exactly the same as stock, working so far. Should be good. I don't know about the stocker being junk, mine had about 63K in 12 years, the last 20K dealing with 100+ HP/TQ. Yours has unknown miles but it is 20 years old (unless you replaced it before). Neither sounds bad to me. The SE compensator is only for the current era bikes, 06/07 and newer.