Handlebar accelerator grip sticking.

The oem (stock) right-hand switchblock has a pin on the lower half which fits into a hole in the oem handlebar, and thereby locates and secures the switchblock to a definite fixed position on the handlebar. (Pin might be on upper half of switchblock assembly -- I don't remember for sure).

This predetermined switchblock location correctly orients the switchblock onto the handlebar, avoids it being pushed too far inward allowing protrusion of the handlebar end beyond the throttle sleeve, and keeps the switchblock from rotating out of position on the handlebar. Is isn't necessary to rely on tightly clamping the two switchblock halves together onto the handlebar in order to hold the switchblock in position by tightly gripping the handlebar, because the pin keeps the switchblock in position, regardless of tightness between the two halves.

Accessory handlebars rarely have such a pre-drilled locating hole, probably because each different bike model would have its own unique hole position. When fitting accessory replacement handlebars, many owners elect not to fool with drilling a locating hole, and opt instead to remove the locating pin and thereafter rely solely on tightly clamping together the two halves of the switchblock onto the handlebar -- at any position desired. With this arrangement, the switchblock sometimes slips, usually by rotating around the handlebar, whereupon shiming or some other method is used to better hold the switchblock in place by affording a tighter grip onto the handlebar.

I would venture to guess the majority of bikes fitted with assessory handlebars are missing the locating pins on the right-hand switchblocks. Thus making it easy to unintentionally allow the handlebar end to protrude beyond the throttle sleeve, and allow the rubber grip to rub against the handlebar.

If not using oem handlebars, fair chance there's no locating pin in the right-hand switchblock on the bike in question.

Good Luck!

Patton wrote:

If not using oem handlebars, fair chance there's no locating pin in the right-hand switchblock on the bike in question.

Well... There was a pin until about 1pm yesterday.

That is about the time of day I filed it off so I wouldn't have to try and line up the place to drill it. Your comment is right on the money.