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Discussion Starter #1
This is my first belt driven motorcycle, it seems to generate belt noise. I believe it is adjusted correctly. Manual says 4 to 6 MM slack. The marks you see on the belt cover are 5 MM apart. Does this look OK to you guys that are more familiar with belt drives?

 

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I get kind of a howl on my bike at lower speeds but I always figured it was tranny noise. Maybe it is belt noise. I did look at belt and it is pretty tight.. Maybe we should loosen the belt up a bit and see what happens.
 

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Which bike? I only have experience with the V-Star 950. If that is what you have your belt is too tight. Manual says 5MM, but accepted norm is 7-10MM. Too tight will tear up the rear pulley bearing. The only noise I ever heard from mine was a squeak (loud) after the front pulley was loose and damaged the belt.
 

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What kind of noise is belt noise. Squealing?
No squealing, no slipping, more like a hum. It may be completely normal. I don't know.
Well, first off Rob you can’t go wrong if you’re doing it to manual specs. I’ve noticed a “hum” out of mine, but only seems to be at certain speeds. I don’t see any wear occurring either.
Stupid question here, but is your belt “tracking” correctly? Not pulling to the inside or outside?
Also, how’s your rear tire look? I’ve had “hum” before from the side edges of the tire being less worn than the center.
 

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Discussion Starter #7
Well, first off Rob you can’t go wrong if you’re doing it to manual specs. I’ve noticed a “hum” out of mine, but only seems to be at certain speeds. I don’t see any wear occurring either.
Stupid question here, but is your belt “tracking” correctly? Not pulling to the inside or outside?
Also, how’s your rear tire look? I’ve had “hum” before from the side edges of the tire being less worn than the center.
Belt looks good, tire is new CT. Tracks and runs great. Mine seems to be noisy at certain speeds also. Belt tracks good, no wear. I may loosen it slightly to see if it makes a difference. It is probably normal noise for a belt drive, I just don't know any better.

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I just got back from a 9,000 mile trip. Bike now has 22,000 miles. For the entire life of the bike I have heard a kind of squeal. I used to think it was the front rotor as my Road Star was noisy there. Then I thought maybe something in the engine, but varying the engine speed doesn't change the sound. It's not always constant or the same loudness. I thought maybe some bearings were dry as it kind of sounds like that kind of hollow squeal. I now suspect it's the belt although it isn't so constant I can make it happen at any given speed, although at high speeds you can't hear that well.

Has anyone changed the tension of their belt yet to see if that quiets down any noise?

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Discussion Starter #9
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I just got back from a 9,000 mile trip. Bike now has 22,000 miles. For the entire life of the bike I have heard a kind of squeal. I used to think it was the front rotor as my Road Star was noisy there. Then I thought maybe something in the engine, but varying the engine speed doesn't change the sound. It's not always constant or the same loudness. I thought maybe some bearings were dry as it kind of sounds like that kind of hollow squeal. I now suspect it's the belt although it isn't so constant I can make it happen at any given speed, although at high speeds you can't hear that well.

Has anyone changed the tension of their belt yet to see if that quiets down any noise?

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I have...made a tremendous difference. I loosened mine to the max of 7mm travel and it is a lot quieter. I still hear it but it is better. This is one of the things I think Yamaha missed on. It should be shaft drive. I have 21k on mine and loosened it at 14k, should have done it at the dealership when I picked it up.
 

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I was getting a loud howl at certain speeds. I checked belt with rear tire off the ground. The tightest spot had only 3mm of slack. Yamaha says 5-7mm of slack at tightest point. I played with the belt slack for a couple of days and ended up at 10mm of slack at tightest spot. I also found out that the marks on the side of the swingarm arn't exactly perfect. My belt would run to the outside of both the front and rear pulley and I knew this wasn't correct. I took cowpuc's advise and spun tire and adjusted till belt was running in center. When I got done it makes very little noise, I think all I hear now is tire noise.
 

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First thing I noticed was that the belt on my SVTC seems a bit narrower (1/8th inch)than the one on my Road Star and Warrior. Outside of abuse, I don't know (personally) of anyone who has changed out a Yamaha belt unless it was at that point of service, and just because the book said to do it.... My SVTC hum comes in briefly at lower speeds, coasting or engine breaking; I have assumed it is tires or the belt...hoping it's not the tranny... The Metzlers on my RS have terrible whine at corners, so I was hoping that was tire noise. I am also decently hard of hearing in the higher ranges so I don't hear it much, or my best riding partner whenever she has important instructions...;)
I can't wait to see what you all figure out; going out to check the belt tension now....but riding partner want the the quad and trailer backed into a narrow spot along a fence...
 

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I just got back from a 9,000 mile trip. Bike now has 22,000 miles. For the entire life of the bike I have heard a kind of squeal. I used to think it was the front rotor as my Road Star was noisy there. Then I thought maybe something in the engine, but varying the engine speed doesn't change the sound. It's not always constant or the same loudness. I thought maybe some bearings were dry as it kind of sounds like that kind of hollow squeal. I now suspect it's the belt although it isn't so constant I can make it happen at any given speed, although at high speeds you can't hear that well.

Has anyone changed the tension of their belt yet to see if that quiets down any noise?

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I have...made a tremendous difference. I loosened mine to the max of 7mm travel and it is a lot quieter. I still hear it but it is better. This is one of the things I think Yamaha missed on. It should be shaft drive. I have 21k on mine and loosened it at 14k, should have done it at the dealership when I picked it up.
I had a howl or growl on mine at certain speeds. The belt tendon was set at the middle to upper manual specs. I found that when I loosened it to the lower end of the specs that the noise went away.
 

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I was getting a loud howl at certain speeds. I checked belt with rear tire off the ground. The tightest spot had only 3mm of slack. Yamaha says 5-7mm of slack at tightest point. I played with the belt slack for a couple of days and ended up at 10mm of slack at tightest spot. I also found out that the marks on the side of the swingarm arn't exactly perfect. My belt would run to the outside of both the front and rear pulley and I knew this wasn't correct. I took cowpuc's advise and spun tire and adjusted till belt was running in center. When I got done it makes very little noise, I think all I hear now is tire noise.
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Is it necessary to take bags off, muffler off, and caliper to get to where you can loosen the axle nuts? On my Road Star the tension was always done by using the "half twist" method which seemed to work okay. Are you using a tension tool?

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Discussion Starter #14
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Is it necessary to take bags off, muffler off, and caliper to get to where you can loosen the axle nuts? On my Road Star the tension was always done by using the "half twist" method which seemed to work okay. Are you using a tension tool?

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You do not have to take the caliper off to adjust belt.
 

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This morning I relieved a little tension on the belt - from maybe a quarter to half a bar of movement in the window at the guard, to almost a full section of a bar in that same little window. The difference is dramatic! Up until today, I have had a loud whine at 25-45 mph in 3rd and 4th, probably limited by my poor hearing...I knew it was the belt because the clutch and engine rev's did not seem to be related. After the adjustment, I heard just a note of whine ONLY when I dove into a hard right hand corner. I did not spin the wheel, but did the adjustment with the bike on the ground. Aligning the rotation might ;-) be a good idea, as well.
My Yamaha service tech said, "Yeah, I probably should have done that; it was at the minimum of the spec when you picked it up...As long as you're not into Jack-rabbit, cowboy,(?) hole-shots, you could probably go just a bit softer...."
I did not remove the bags or the pipes, though it would have helped... A little, actually, about a foot and a half, of leverage on a 12-14" wrench sure helped though.
 

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If you want to adjust the belt tension correctly you need to remove the bags and the mufflers as there are torque specs that need to be followed. It also allows you to see the alignment marks by removing the bags and mufflers so you are correctly lining up the alignment marks so the bike will track straight down the road.

The bike needs to be at ambient/room temp when you adjust the belt and the belt has to be dry as well.

Follow the factory specs, these companies have spent millions of dollars developing these systems and they know what works. Too loose of a belt and you risk jumping a tooth and stripping the belt, too tight and you risk breaking the belt. I can live with a little belt whine knowing it is set to factory specs.

Don't worry about the belt being on the left side of the rear pulley or the right side of the rear pulley as long as the alignment marks are correct and the motorcycle tracks straight down the road you are good to go. Trying to get the belt to ride in the middle of the rear pulley is a waste of time and effort and you may end up with the alignment being a little off and the motorcycle not tracking straight. My belt rides to the right side of the rear pulley and the motorcycle tracks straight down the road at speed with your hands off the handle bars.

When you are out look at other motorcycle and you will see that all of them the belt will be either on the left side or the right side of the rear pulley and you will be very hard pressed to find any where the belt tracks in the middle of the rear pulley.
 
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