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Discussion Starter #1
my LT makes a noise that is obviously nothing serious because it has done it for over 70,000 miles but it has always bothered me want it is. it's done it since the bike was new. it's a rattling sound when the bike is going slow and the engine is not pulling, like when going down an incline. i have checked the muffler and everything i can think of on the outside of the motor and there seems to be nothing loose,. Anyone now what this is?
 

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rear brake rotor?
 

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Ditto on the rotor, aka 'The Cow Bell'.
 

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2005 K1200LT
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Not the rotor as Al no longer has one on his trike. I suspect it is the gear train from the crank to the alternator to the output shaft. As these rattle like heck under a very light load. Here are just two of the three gears I am talking about.
 

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jzeiler said:
...I suspect it is the gear train from the crank to the alternator to the output shaft. As these rattle like heck under a very light load....
I think this is probably it, my bike sounds like I am tumbling rocks when I loosen up on the throttle right around 2,300 RPMs. I am pretty sure what John describes above explains my noise. Now that I have (almost) eliminated tupperware racket I hear this noise all the more.
 

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Just another reason to always wear earplugs :D

jzeiler said:
Not the rotor as Al no longer has one on his trike. I suspect it is the gear train from the crank to the alternator to the output shaft. As these rattle like heck under a very light load. Here are just two of the three gears I am talking about.
 

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OK, I don't understand all this. What is wrong with my bike. It makes no unusual/bad noises at all. It sounds the same as my K1100LT. Do I have a defective bike?

Robert
 

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John would maybe have a better opinion on this, but try loading up the alternator by turning on the high beam, both seat heaters, and the grip heaters all at the same time. If the noise lessens or is eliminated, this confirms it's the normal gear lash in the alternator drive.

Robert, some of them do it and some don't but it's pretty common and nothing to worry about. Mine is only bad when it's a cold start and then it has an obvious rattle.
 

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2005 K1200LT
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Scouter-50 said:
OK, I don't understand all this. What is wrong with my bike. It makes no unusual/bad noises at all. It sounds the same as my K1100LT. Do I have a defective bike?

Robert
You may be one of the lucky one's that got a closely matched set of gears that don't rattle. Mine has sounded like a bucket of rocks at idle since new and I have been next to some that were absolutley quiet.
 

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Discussion Starter #10
deanwoolsey said:
John would maybe have a better opinion on this, but try loading up the alternator by turning on the high beam, both seat heaters, and the grip heaters all at the same time. If the noise lessens or is eliminated, this confirms it's the normal gear lash in the alternator drive.
It does alternator rattle when it idles but I think this is something else. It does it when the bike is moving but not under load, like when coasting. It sounds like something under the motor. I thought it could be the side stand or center stand but these were taken off in it was triked.

It seems like I read somewhere that the push rod between the slave cylinder and clutch can rattle when not engaged. Is that a possibility? I've never tried pulling the clutch lever to see if that stops it.
 

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If it makes you feel better ;I also have the same rattling sound on my LT ;just turn the radio up.
Gary
 

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2005 K1200LT
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alstrickland55 said:
It does alternator rattle when it idles but I think this is something else. It does it when the bike is moving but not under load, like when coasting. It sounds like something under the motor. I thought it could be the side stand or center stand but these were taken off in it was triked.

It seems like I read somewhere that the push rod between the slave cylinder and clutch can rattle when not engaged. Is that a possibility? I've never tried pulling the clutch lever to see if that stops it.
I will rattle but I don't think you would hear it. They also started using a rod with a groove to hold a felt sleeve to quiet the rattle but I don't have info on what year they started that.
 

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Try loading up the alternator. After you have ridden for awhile the battery gets fully charged and at times it essentially coasts, which accentuates the gear lash issue. One other possibility is that you may have a cracked manifold or loose exhaust bolt.
 

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mine has a very quiet motor but there is an idling rapping noise common to these motors - more about it on K1100 threads than here - both my K100 and K1100 were slightly noisier than the my LT altho their exhausts were quieter
 
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