Oil pump chain issue

[Romeo]

I have had a continuing issue with a scraping sound coming from what seems like inside the transmission housing. It seems to be rotational, but I only hear it when I am rolling down the road.  Do not hear the sound when the engine is in neutral, or the clutch lever is pulled in. I seem to remember someone else having a similar problem.  See that the oil pump drive chain is located in the same area and am wondering if it’s could be the culprit, even though it is running all th time and I only hear the scraping sound while in motion.

[Ricky-D]

Look to the rear wheel and drive line for your answer.  It has nothing to do with your oil pump drive assembly.

***

[Chrisj CMA]

I have had a continuing issue with a scraping sound coming from what seems like inside the transmission housing. It seems to be rotational, but I only hear it when I am rolling down the road.  Do not hear the sound when the engine is in neutral, or the clutch lever is pulled in. I seem to remember someone else having a similar problem.  See that the oil pump drive chain is located in the same area and am wondering if it’s could be the culprit, even though it is running all th time and I only hear the scraping sound while in motion.

If it we're the oil pump chain scraping it's guard you would hear it at low load situations like idle and gentle blipping of the throttle.

[John Schmidt]

I agree with the other guys on the possible source. Get the rear end jacked up and spin the rear wheel, listen for unusual noise in the area of the left side of the wheel....possible wheel bearing going out. Or, if it sounds more toward the rear of the motor, might be the u-joint getting ready to say bye-bye. If you hear anything, it's time to pull the rear wheel and final drive and inspect. Doubtful it's the chain.....possible but not probable.

[Romeo]

Guys, we ruled out the rear end a long long time ago. The final drive is dead quiet. It’s been checked and rechecked. Everything looks and feels and sounds fine. I have been chasing this sound for two years, I agree, it doesn’t seem like it would be the drive chain if it goes away when in neutral or idling, and I I’ll also admit I am grasping at straws at this point. We changed the u-joint just because it was easy to do.
We pulled the driveshaft, checked the splines, absolutely no wear at all, well lubricated, pinion cup looks fine. But! I will look the pumpkin and it’s inhabitants once again, just because. Thanks for the input.

[Chrisj CMA]

We had a bike making a similar noise. Turned out to be a wallowed out bearing seat. The bearing kept moving around making the noise.  If you have a spare wheel, or can get one to borrow. Worth a try

[fudgie]

Clutch?

[Bagger John - #3785]

Clutch?

Notice anything funky with the lever pull?

Damper plate is a possibility.

[Glaserbeam]

I'll add an out-of-left-field idea:  My front brake discs (not worn out, and with new pads) make all kinds of bizarre scraping sounds when in motion, unlike any other bike I've had. Seems to do with the way they're flex-mounted to the disc hubs.  With light application of the front brakes, the discs are loud, grinding/scraping.  Maybe your pads are rubbing on your discs a bit?  See if applying the brakes changes the sound?

[Romeo]

I have the clutch off the bike as of now. All seems correct, no out of line discs or any indications of missing rivets. The lever worked flawlessly. As far as the front brakes, O actually removed them from the rotors, and suspended them from the frames and went for a ride, the noise was still there.
The rear wheel has been recently off the bike for powdercoating, new bearings installed. The noise was there before I did this, at it’s still there afterward.

[Bagger John - #3785]

Is there a particular gear in which it's more prevalent?

Present on trailing throttle as well as under power?

[Romeo]

Doesn’t matter which gear, seems more prelevant when slightly lugging the motor, also present whether on accel or deccel.

[Punisher]

I have had a continuing issue with a scraping sound coming from what seems like inside the transmission housing. It seems to be rotational, but I only hear it when I am rolling down the road.  Do not hear the sound when the engine is in neutral, or the clutch lever is pulled in. I seem to remember someone else having a similar problem.  See that the oil pump drive chain is located in the same area and am wondering if it’s could be the culprit, even though it is running all th time and I only hear the scraping sound while in motion.

Ping Grumpy in Florida.   He had a noise and it was something that the oil pump chain slides on had come out and was letting the chain rub the case.   I don't recall under what circumstances the noise presented itself but he had to split the case to find/fix it.  Said if he had known what it was for sure causing the noise he would have lived with it as it was a lot of work to resolve.

I just looked back through some messages I had from Grumpy and here is something else he said about a noise:

[Gumpy]
Some thing I have run into, the spur gear that runs off the clutch, part of the starter clutch is a split gear that has to be preloaded . the 2 gears are same size with a spring between them, the gears have to be preloaded them slid together, that removes all the slack.  If some one just slid them together, I have seen some come from the factory that way, they will rattle.
[End Grumpy]