Cuts out at highway speeds - 2002 Yamaha Road Star Silverado

Accelerate while on the "on ramp" until you reach the speed limit + posted on the highway... this way when you reach the highway you will be going the same speed(or close) as the other vehicles ..you can blend in easily.. and NOT cause an accident by going too slow!! On the way down the "on ramp".. start looking at the traffic coming on the highway to find an opening to ease into safely. Use your mirrors and BLINKER... (its easier to slow down a little than speed up)

at speed , 2 possibles come to mind
blocked muffler
lack of fuel --check vent, filter

is there any check engine lights on? also a leak in the vacuum lines will make it jump in and out of over drive. could be a few problems. wish i could help more, sorry. if you have a vacuum leak it would also make you heater controls not work like they should, like if you put it on defrost it will only come out the vents and so on.

sounds like balljoint not installed correctly

It could be something as simple as a vacuum line,but sounds fuel related. Possible pump.get a fuel pressure reading done and if pressure doesn't hold.....suspect fuel pump

try changing the fuel filter

yes fuel pump is dying (it's old ) it will finnaly give up the ghost some day soon then engine won't run at all

common problem pump heats up and shuts off cools off and runs again cyclic

this all assumes you have kept up on changing the fuel filter at reg intervals too

Have your idle air control valve checked

Does it run good when it is runnig as good as it used to? Is the check engine light on or does it come on before it stalls? If it weret for the days of computers just sounds like overheating as from clogged exhaust

Check your rad hoses. They will tend to collapse (**** in) & cut down on flow at highway speeds, more than city, due to increased demand & flow on cooling system. If they don't feel relatively stiff, I'd change them. You might even see them **** in while sitting and revving the engine a bit.