Hi, ya some tutorial on youtube have teach me how to inspect the drive belt, but i cant find one for my xl883n (17) for adjustment, i can't even find on the service manual is that easy to do it myself? is there a risk to lead the rear wheel to unbalance (i know understand why they need to measure the axle?

 

Which manual do you have? The factory manual should have a how to for adjustment and belt tension. My Sporty is older , so I'm not sure how it may be different from yours, if at all.

 

Get yourself the Belt Tension tool from Harley and there is many videos on you tube on how to do this. I took an o-ring and put on the tension shaft at the 10 lbs mark so when I'm on my back on the floor I don't have to worry where the 10 lb mark on the tension gauge, I just push it up on the belt till it hits the oring in the gauge. There is a slot with a few hash marks on the lower belt guard to see when you push up with 10 lbs of pressure how much the belt deflects. Most of the time and, check the manual, it should be about 3 to 4 hash marks or like 1/2 to 3/4 of an inch. Then i take this extra step, I roll the bike forward about 5 feet and check it again to double check my reading. This is all done on the jiffy stand. Do not roll it backwards to do this as it will give a false reading as it walks the belt a bit the other way a hair. Grab the disk version of the shop manual for about $30 off eBay, it will save you a ton of time and aggravation learning to do it yourself, and not $100+ for the print manual .

Also compared to a chain and some of the older models these belts are far tighter than even I remember them being. They were even tighter on the XB model Buells and the XR1200s as they have the added idler on the belt .

 

My 2012 Service Manual allows for 1/4" to 5/16" of deflection with 10lbs of pressure. If the belt needs to be adjusted, you would also want to make sure the axle was aligned to 90 degrees after tensioning the belt.

I bought the following tools to do the axle alignment and belt tension:
Motion Pro Wheel Alignment Tool - Part number 080368 - Less than $20 on Amazon
OTC Belt Tension Gauge for belts requiring 10lbs of pressure to align - Part number 4748 - About $21 on Amazon
V-Twin Hollow Axle Plugs - Part number 16-0332 - $20 on Amazon

The only special tool that my service manual calls for during the process are the axle plugs to find dead center of the axle. The axle plugs are not available for sale to the general public, so you have 2 options. The V-twin plugs or Jim's USA Machining. Jim's plugs will run about $130 just for the plugs. I opted for the V-Twin.

The process summed up is:
1. Adjust belt tension using the specs above
2. Insert axle plugs and measure the distance between the center of the plug and the center of the swing arm pivot bolt on the belt side(There are dimples in each for a precise measurement with the Motion Pro tool)
3. Adjust the brake side to the same measurement. Re-check the belt tension but it should be within spec.

A lot of guys just adjust the belt by guessing the 10lbs of pressure, and measure the rear axle with a tape measure, welding wire, or wire hanger. I wanted to be precise to extend belt life and get the axle at a perfect 90 degrees. If you just try to eye ball the axle or if the angle is off, the bike could potentially pull itself down when you lean in to a turn. Having the axle at 90 degrees is critical. The measurements should be from the swing arm pivot bolt to the axle center. The axle is not the same diameter on each side so measuring the to the outer or inner edge of the hollow axle will not work.

Hope this helps.

 

ya but what should i do if i find the alignment is not correct?