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Discussion Starter · #1 ·
When holding a steady 20 mph in second gear the engine has a murmur/buzz/hum for about 4 seconds, then normal for 4 second, then does it all again until I accelerate.
I notice it when in intown traffic.
Disengaging the clutch also makes the symptom go away so I don't think it is in the drive train.
The engine and carbs are completely stock.

Thank you
Don
 

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When holding a steady 20 mph in second gear the engine has a murmur/buzz/hum for about 4 seconds, then normal for 4 second, then does it all again until I accelerate.
I notice it when in intown traffic.
Disengaging the clutch also makes the symptom go away so I don't think it is in the drive train.
The engine and carbs are completely stock.

Thank you
Don
Your ear plugs are not in properly.
 

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Most like an occasional buzz?

When holding a steady 20 mph in second gear the engine has a murmur/buzz/hum for about 4 seconds, then normal for 4 second, then does it all again until I accelerate.
I notice it when in in town traffic.
Disengaging the clutch also makes the symptom go away so I don't think it is in the drive train.Don
Mr.xackley,

To be clear, when shifting gears, or when cruising along and you pull in the clutch, this "murmur/buzz/hum" goes away, or under acceleration?

If that is the case, that would seem to indicate that it is, in the drive train. Or maybe I'm reading this wrong?

In any case......
1. Is your chain in good service condition, appropriately tightened, and lubed.
2. Are you sure nothing is loose. A rhythmic buzz can be a symptom of vibrating parts. Like fenders, exhaust, chain guard and such. That sounds like what heat shields can do on cars.
3. The drive sprocket nut on these bikes have been known to back off. You might pull the sprocket cover and look for that. An indication, even with the lock washer in place could be a rusty deposit around the splines.
4. When hot weather arrives for good, I change my oil viscosity to 20-50. If you due for an oil change, you might consider that. It's a long shot, but if it's clutch related it might make a difference.

Namaste,
Charles
 

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Discussion Starter · #4 · (Edited)
Edit: this only happen when holding it steady in the low 20mph range. ERM.....ERM.....ERM....
Is there any "environmental" system that turns off and on and might flutter?
It is amazingly smooth in all other situation for being a vertical twin.

The previous owner told me about the vibration when I bought it. I can avoid towns so I didn't notice until yesterday.
He had taken it to the dealer in canandaigua ny. The PO said they went over the drive system and did something with the cush drive. No change.

I will double check their work, as you suggested.


I just did the oil, 10-40 full synth, I hadn't read of anyone using 20-50 until your post. I guess I could drain it and save it for later. Only a couple hundred miles on the oil in the last few of days.

Don
 

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Still got a buzz

Edit: this only happen when holding it steady in the low 20mph range. ERM.....ERM.....ERM....
Is there any "environmental" system that turns off and on and might flutter?
It is amazingly smooth in all other situation for being a vertical twin.

The previous owner told me about the vibration when I bought it. I can avoid towns so I didn't notice until yesterday.
He had taken it to the dealer in canandaigua ny. The PO said they went over the drive system and did something with the cush drive. No change.

I will double check their work, as you suggested.


I just did the oil, 10-40 full synth, I hadn't read of anyone using 20-50 until your post. I guess I could drain it and save it for later. Only a couple hundred miles on the oil in the last few of days.

Don
When you said environmental that made me think of the air injection system. Is yours still on the bike? If so it could be the vacuum diaphragm under the tank vibrating. Remove the vacuum hose that goes to the diaphragm, I think it comes off the left carb, and cap off the spigot. See if that changes anything.

The cush drive at the rear hub would be a very long shot.

I wouldn't rush out to get some 20-50. It's just my personal choice when the weather gets hot, and I doubt it would make a buzzing difference.

Charles
 

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Discussion Starter · #6 ·
I disconnect the hose and did a vacuum tube connecting the 2 carbs as I didn't have a cap.
Same symptoms, but I narrowed it down to only 2nd gear when between 20 and 25.
3rd at 20 mph or at 30 mph everything was normal.

So I am going to just assume it is no big deal, and avoid cruising in 2nd when the traffic dictates low 20s.

Thank you
Don
 

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do 2007 bikes have a speedo cable?
old cables can sound a bit strange when bone dry or have a kink. Mine for some reason buzzes when I brake. I think that it’s because as the cable becomes a little tighter (compressed forks) it rubs more inside the cable sousing housing more causing friction and vibrations.

just food for thought.
 

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I know this may sound outta left field, but my 2006 Scrambler has a similar thing happening and I think my problem is a warped brake rotor. Common issue I believe
 
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