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Ralph2
09-21-2008, 01:03 PM
Hi All. First post and recent UK based graduate to an XB9R. I've owned a few twins and they all vibrate but the Buell is the most vibratingest of all and I love it! First let me say what a great resource the forum is. I've spent hours reading up here and it's helped with a lot of questions. I still have one or two though so here goes with one of them: At around 80-90mph it has a vibration that modulates around 90 times a minute. 'Listening' to what the bike is saying I think it is the drive belt,and I'm guessing it's a harmonic with the engine because if I drop a gear it all changes. None of which is a problem to me if it's normal. I'm just concerned the belt might stretch under these conditions, or may already be too loose. I can just turn the idler wheel against the belt but it's pretty stiff. What do you think? Anyone else noticed this?

Bordsnbikes
09-21-2008, 01:33 PM
Some more specifics would help. What year is the bike? How many miles? Who's done the services thus far?

Ralph2
09-21-2008, 03:07 PM
Yes, the bike is an October 2002 build, completely stock parts, 4,000 miles old and two services by an HD Dealer. Original belt as far as I'm aware, early type. Standard tensioner pulley. It's hard to see the condition as the guards are all-enclosing. The bit you can see round the rear sprocket looks OK, there are lighter discolouration stripes on the back of the belt between the teeth. I haven't taken off the front sprocket cover yet to take a better look. I love the idea of belt drive but with no experience of them until now I'm clueless as to what's normal and what's not. Thanks.

LeFox
09-22-2008, 10:29 AM
if it's an early belt en the tensioner/idler wheel is going turnable, but it's hard...you're still ok.

you should still have a few more miles in the belt. if it breaks, get the upgraded sprockets & belt ;)

LeFox
09-22-2008, 10:30 AM
and also...welcome to the fun side of life http://users.telenet.be/mdr/fun/smiley/welcome.gif

Ralph2
09-22-2008, 10:45 AM
Thanks in reply to both your posts! :)

typeone
09-22-2008, 03:12 PM
i would check primary chain tension first, there is usually a 'tight' section that you use when adjusting to spec. if the chain gets too loose or is adjusted too tight, you can experience a similar modulating vibration youve explained. it could be that the HD tech adjusted the primary chain incorrectly by not using the tightest section of chain. pretty easy to do.

not sure if this will solve it but i would look there before the final drive belt.

Ralph2
09-23-2008, 07:46 AM
Thanks for that typeone. I'm changing the oil so I'll check it then.

skellybuell
10-09-2008, 12:57 AM
Yea i agree wth Lefox about the upgrade on the sproket and belt i also have an 03 firebolt and snapped my belt several times costing me over 300 bones, I wish i changed it sooner for only 4 and some change now im at like almost 800 on a belt so first chance i would get the upgrade..... not to mention if you have the dealer do it = alot more money

skellybuell
10-09-2008, 01:00 AM
By the way if it is the primary it would cause alot of jerking in lower gears if it istoo loose so that would be first sign ;)