WTB K1100 12 Rivet Output Shaft

[PeterA]

Hello Everyone, Looking for a 12 Rivet output shaft for my 85 K100 - original 6 rivet is making a noise a idle.

[daveson]

Are you sure it's the output shaft and not something else?

Does the noise suddenly disappear at a certain rpm?

From the limited sample of cases that I'm aware of, I think I've noticed a pattern emerging wherein if the noise suddenly disappears at about 2,000 rpm, the problem is likely to be related to the auxiliary shaft, if at about 3,800 rpm, related to the output shaft. But with the output shaft dampers, I think the noise slowly disappears with an increase in revs, and also reduces as the engine slowly warms up.

Another check is that with the crank cover removed, you can see and feel if the output shaft rivets are worn, or some may even be missing.

[PeterA]

Hi Daveson,

I get a rumble sound when the throttle is blipped - not at idle and if you slowly move up through the rev range there is no noise. Could be coming from Alternator area and doesnt sound as bad as some bikes with an obviously bad output shaft. Good to know you can do an inspection via crank cover to confirm before ripping that deep into the engine. Bike as done 114,000kms and otherwise all good.

[daveson]

The alternator is easy to remove. Then you have access to the rubber monkey nuts that drive the alternator. If they're worn, you probably don't have to remove the crank cover.

[PeterA]

Thanks again Daveson,

I'll take a video tomorrow night and post.

Also when pressing the starter it pauses like compression lock (not enough guts to turn over motor), release button and push again and instant start. Battery going bad or electrical contactor issue?

Regards
Peter

[frankenduck]

The alternator is easy to remove. Then you have access to the rubber monkey nuts that drive the alternator. If they're worn, you probably don't have to remove the crank cover.

In theory it is easy to remove. In practice, not so much. The threads of the three bolts that mount the alternator tend to be corroded so they can be hard to remove, especially the "buried" one in the middle. Taking the coils off to get better access to it and leverage with a good Allen wrench is advisable.

Signed,
Someone who has taken off lots of alternators.

[Laitch]

A wobble extension of a suitable length also can make things easier with alternator bolts, rear drive attachment bolts and other situations where bolt alignment into a socket with an extension could be slightly offset.

[daveson]

Also when pressing the starter it pauses like compression lock (not enough guts to turn over motor), release button and push again and instant start. Battery going bad or electrical contactor issue?

Hopefully it's simply the battery. It's starting to sound like something completely different. I've heard of that symptom before, I wish I could remember what the solution was. It might be worth trying to pinpoint the location.

If you end up checking the monkey nuts and they're good, another check is to see if the noise is gone with the alternator temporarily removed.

If the noise has gone, strangely that doesn't mean it's related to the auxiliary shaft. There have been cases where the noise suddenly disappears at about 3,700 rpm, and replacing output shaft parts has fixed the problem, but the noise was gone before the repairs with the alternator removed! Why, you ask? Don't ask. But here's a thought, the crankshaft and some other bits, turn anticlockwise, the output shaft, alternator, and some other bits, turn clockwise, so removing the alternator might affect the balance.

[Laitch]

Also when pressing the starter it pauses like compression lock (not enough guts to turn over motor), release button . . .

Load test the battery to determine if it is weak; clean and tighten the battery post connections and the battery transmission ground connection. If those are okay, consider cleaning the starter commutator and checking the length of the starter brushes.

[daveson]

Ay Pete,

An easy, maybe crude way to clean the starter. Key off, clutch in, third gear, roll your brick backwards, then release the clutch, maybe a few times. If it now starts normally, the starter was dirty.

Just cause a lazy man would be happy to clean it that way, that doesn't necessarily mean you'll ever see me do that.

[PeterA]

Thanks Daveson,

Here is the grumble noise - output shaft, monkey nuts or something else? Any ideas? Please see link below..
https://drive.google.com/file/d/128548wKrYy0Q005aXY69E-i2878ywiz6/view?usp=sharing

[daveson]

Dunno, hopefully just alternator monkey nuts. Maybe I should say it this way, the alternator is easy to get to. That's something I like about bricks, so many bits that are easy to get to. What about the output shaft you ask? Don't ask.

If the nuts are toast, replace them. Maybe try to find the cause. They might actually look good, but be shrunken and hardened, so loose and noisy.

It's also easy to get to see the rivets. It might be a bit tight, but you can spin the crank cover around the radiator hose, instead of removing the hose.

I don't think it's the output shaft dampers, cause it's not really noisy at idle. Also I think output damper noise reduces as the engine gets warm.

Anyway I think I'd look at the alternator first, if all good, look at the rivets. Or look at the rivets first.

[Laitch]

Looking for a 12 Rivet output shaft for my 85 K100 - original 6 rivet is making a noise a idle.

If you only need a 12-rivet absorber gear rather than the entire shaft assembly, this thread might interest you, considering how difficult it is to find this part from K1100 or other earlier 4V models. It is also possible to drill out the rivets of the 6-rivet model and install 12 bolts instead of rivets, like this.

[Laitch]

Here is the grumble noise - output shaft, monkey nuts or something else? Any ideas? Please see link below..
https://drive.google.com/file/d/128548wKrYy0Q005aXY69E-i2878ywiz6/view?usp=sharing

I don't hear anything alarming. Consider replacing the spark plugs with the correct type and balancing the throttle bodies.

[daveson]

Yep, it doesn't sound too bad, hopefully no movement will be seen at the rivets.

Another thing, even K1200's are getting old now, so replacing with a second hand part will buy you how much time? If not too bad, you could just buy some rivets, and get some new parts like bearings, rattle spring, ect.

One more thing, if one of the cylinders isn't getting enough fuel, that can result in a knock, which makes me wonder if it's come out of storage lately or ridden regularly. But I spose there would be a vibration with that. It's an easy test to point a temperature gun at the headers to see if they're all at about the same temperature. If this test result isn't good, I wouldn't even bother looking at the monkey nuts or the rivets.

[daveson]

I'm often forgetting about the simple stuff.

If it's due for a service, give it one.

Hasn't had a new filter, give it one.

Loose spark plug leads? High resistance?

Even if it doesn't help the problem, maintenance is good to do.

[daveson]

Since this brick is new to you, you might be planning to remove the gearbox to lube the splines. If so, while you're there, check that the clutch parts have been installed properly with the balance marks. There has been at least one case here where it was unbalanced, causing a knock.

If you do remove the clutch, or the rear main seal is leaking, this is also an ideal opportunity to check the output shaft circlip. It's unlikely that this would be the cause of the knock, but it might be. I mention this because if you're there anyway, it costs nothing to check. The circlip also applies spring pressure (if it's the castellated type) it could be weakened. It might be installed the wrong way around, the concave side should be facing towards the bearing. It might not be fully installed in its groove. All these possibilities could result in excessive endfloat and a knock. Again, unlikely, but it's a part of the output shaft that is easy to get to, and I think it's less than $10, so cheap and easy to get to.

[PeterA]

Thanks again Daveson,

Working on the lack of power and breaking down issue I posted about on another post. Curiously it didnt break down today after a 100km ride but it was not a hot day. I've got some parts on order for a service and I've found a coil I can swap in. We've noticed the crank case breather pipe is cracked so that needs replacing and will do a clean of earth points and inspection with tank off. Looks like crank case cover gasket needs replacing as its seeping so some general maintenance jobs as well.

Will report back as we progress through diagnosis.

Regards
Peter

[daveson]

Goodo replacing the breather hose could fix the lack of power problem, it might even fix the knock problem. Maybe test the coils before buying new. I'm thinking coils is something you want to buy as a pair, you want them to be the same, I'd say.