Primary Drive Noise

icemann427 · #1 (**permalink**) 05-21-2023, 09:37 AM

Hello,

I have owned a Big Bear Chopper powered by a S&S 124, Baker 6spd, and Hi Tech Open Belt Primary Drive for 17 years. For all intents, it has been a maintenance free bike the whole time.

Recently, I noticed a noise coming from the left side, seemingly originating somewhere from the belt drive system. I can't exactly describe the noise, but after riding the bike for that long of a period, I think I know when something is off.

I removed the clutch and noticed the pulley was just a bit loose before removing it and thought that was probably the culprit. I took it apart, cleaned everything, and reassembled it, ensuring it was tight.

I started it up after reassembling it and thought I had fixed it since I did not believe I heard anything wrong. With that said, I went to ride it the next day and to my displeasure, still heard a noise that troubled me. With the engine running, I located the noise to the area of the front pulley of the Hi Tech drive. I still really can't describe the noise, but it just doesn't sound right.

I disassembled the front pulley from the shaft and cleaned everything. The pulley seemed tight with no wobble, whatsoever, and the nut was almost impossible to remove, and as such, I don't think looseness was a problem.

Once the pulley is removed, one can see a round black plastic cover that rotates with the shaft. There are two holes on the plastic cover, one of which has threads. Neither hole had anything in them as I could tell but do not know if something is supposed to be attached in them. The cover can wobble a little bit, but I am fairly certain it does not when the pulley is reassembled and everything is tight.

The black cover seems to be between the engine case and the Hi Tech Primary Drive plate that attaches to the engine case. I looked at a schematic of the S&S 124 and do not see that plastic cover, nor does the schematic tell what was behind it, for certain. I did see bare copper wiring through one of the small holes in the plastic cover, so I'm guessing there is a stator or something similar behind the cover, but what I could see was very very minimal so it is difficult for me to make an affirmative statement. As well, the plastic cover does not show up on the Hi Tech schematic, either. So, I'm a bit lost.

Can someone please tell me what is behind the black plastic cover? And, what I might be hearing? While I am fairly mechanical and have rebuilt automotive engines and have taken care of this bike for those 17 years, in no way am I a V-Twin expert. But, I would rather not have to take it to a mechanic if at all possible.

I tried to upload a couple of pictures, but can't figure out how...

Thanks so much!!

pushrod243 · #2 (**permalink**) 05-21-2023, 04:34 PM

With the miles it has I'd suggest replacing the clutch hub bearing and the inner primary bearing. They are sealed but the stock HD uses a standard bearing that sees oil to cool it. My guess is yout noise is there.

icemann427 · #3 (**permalink**) 05-23-2023, 02:06 PM

"With the miles it has I'd suggest replacing the clutch hub bearing and the inner primary bearing. They are sealed but the stock HD uses a standard bearing that sees oil to cool it. My guess is your noise is there."
__________________

Thank you for your reply. Much appreciated. I do not hear the noise in the transmission or clutch area, but perhaps you are suggesting I change the hub bearing, anyways.

I hear the noise at the front pulley area coming out of the crankcase. By "inner primary bearing" are you speaking of the one on the side of the crankcase inside of the front pulley?

Thanks!!

golfish · #4 (**permalink**) 05-27-2023, 10:06 AM

Quote:

Originally Posted by icemann427

Hello,

Can someone please tell me what is behind the black plastic cover? !

The charging system maybe. I don't think I've ever seen a plastic cover..could be something over the rotor.

https://www.jpcycles.com/product/v-f...BoCHfsQAvD_BwE

icemann427 · #5 (**permalink**) 06-12-2023, 08:29 PM

Thank you for everyone's help. I thoroughly cleaned the front pulley area, reattached the pulley, and shot some WD40 in the outer bearing that keeps the front pulley aligned in the outer primary cage and no more noise. Other than just guessing the outer cage bearing was perhaps dirty and I cleaned it out by spraying WD40 in it, I don't know what has changed for the noise to be eliminated.

Again, thank you pushrod and golfish for your help!