carb alignment

Hello All I am just about ready to tighten the screws down on the carbs that hold them all together and started wondering about the alignment does anything special need to be done different here or are the rails sufficent ??

 

You need to hold the carb throats---the ones that FACE THE CYLINDER HEAD----down onto a perfectly flat surface (Yamaha suggests a piece of plate glass) while installing and tightening the upper and lower rack mount screws to insure proper alignment.

If you don't get proper carb-to-carb ("rack") alignment, you'll never be able to get them to synch properly, and may have a problem with one or more throttles binding.

You just lay all the carbs "throat down" onto the glass, hook the little guys together (throttle shaft arms, fuel tubes, etc.), and then start installing the rack screws. Keep something on top of the airbox-side throats (piece of flat wood) to put some force to make sure the front (cylinder side) throats stay in contact with the glass plate. As you install and tighten the rack screws, make sure the cylinder side throats stay in contact with the glass plate.....the carbs will try to wiggle around as you snug up the rack screws.

 

Tanks Chacal that what i love about this site no matter what you screw up lose or break someone is out there witha solution. Thanks to all who make this site possible

 

Chacal's comments are very true and this is a good tip I experienced some real binding of the throttle butterflies when I put my XJ650 carb rack together the first time, had to remount them to get the butterflies to close promptly without binding. Couldn't figure it out, but he is right on with this tip, there was enough freedom to allow binding to occur.