78 XS650 Whirring sound

[clegg]

I just acquired another project XS. Cleaned the BS38 carbs and got it running but it's making a whirring sound. Possible cam bearings? It goes pretty well down the road.

I do not recall my others sounding like this . It shows under 5000 miles on the odometer.

I will try to add a video.

 

[clegg]

I just searched. There are quite a few threads on this. It sounded like cam bearings to me but possible chain tension or guides..

 

[xjwmx]

Prime suspect would be the crankshaft. See if the generator end of it is wobbling with the bike running. See if the right side is wobbling by taking the cover off and using the starter to turn it, doing something to make sure it doesn't start of course.

 

[thuban]

Did you happen to change the oil and take the bottom filter out and check for pieces of cam chain guide. Might need an oil change? Or did you adjust the cam chain. Regular maintenance items as well as trouble shooting.

 

[clegg]

@xjwmx- I removed the left side cover, the rotor really has no wobble at all.
@thuban- Brand new Rotella in it. I did not remove the bottom sump filter although, I did check the strainer on the side. there was a very small amount of metallic particles. The cam chain was adjusted a while back. I just checked it again.

I may need to take a peek at that sump filter.

 

[xjwmx]

@xjwmx- I removed the left side cover, the rotor really has no wobble at all.
@thuban- Brand new Rotella in it. I did not remove the bottom sump filter although, I did check the strainer on the side. there was a very small amount of metallic particles. The cam chain was adjusted a while back. I just checked it again.

If you see much aluminum it's evidence the front guide rubber may be gone, but they really do not make a lot of noise. You might try loosening the chain just the right amount and see if the whirring changes as you tilt the bike and and the chain gnaws on the guide differently. To me that would confirm the rubber is gone. Also, one side not wobbling doesn't mean the other side isn't. It makes quite a noticeable whirring compared to a bad guide

 

[thuban]

Clegg,
What year is your yam? What weight is your Rotella? Yep, What xjwmx said.

 

[clegg]

1978 15-40 rotella . It whirred before the oil change.

 

[thuban]

Your still having fair weather? It's a tough one. Some guys have took a short video of running sounds and up-loaded them. I think the video has to be hosted somewhere else.

 

[clegg]

Very nice weather here. It was in the 80's today.
I have a vid but need to upload.

 

[Jim]

To give us a video, upload it to Youtube and copy the "share" link. Click on the film strip icon in the comment box (red arrow) and paste it into the pop-up window.

 

[clegg]

 

[clegg]

Thank you Jim!

 

[member28833]

Hey Fun First video attempt ever

 

[Jan_P]

Hi

For what it is worth
https://xs650temp.proboards.com/thread/14708

20W-40 was the original spec from Yamaha. Only problem is they're the only ones who sell that weight. I think most of us use a 20W-50 of some kind. Many do run the 15W-40 diesel oils but be aware that with the thinner rating (40 vs 50), you will hear more mechanical noise from your motor. I tried it but switched back to the 50W because of that. I just use regular oils, nothing fancy, and change it often (1000-1500 miles).

After posting above listened to the video --Valve clearance checked lately ? ...???

 

[Jim]

That sounds like a bent crank whirring to me. As was pointed out above, you'll need to remove the right cover and watch the primary gear and see if it wobbles.... but that sounds like the irregular meshing you get on the primary when the right side's bent.
Fwiw... running the engine for 10-20 seconds without the cover or oil wont hurt a thing.

 

[thuban]

Bent crank? How does that happen in routine operation?

 

[joebgd]

Idk my first impression is just clutch noise. The bike was sitting a long while I would bet, only 5,000mi. I would ride it quite a bit and keep an eye on oil and take notice of the sound as you put miles on it.

 

[thuban]

Hey Fun First video attempt ever

We've opened Pandora's box!

 

[member28833]