I own a 1998 LS650 and I have had a problem with it. It started dieing at 80 mph. It would be going fine, then it would have intermitten power with a few backfirings and it would just lose all the power as if i pulled the clutch in. So i pulled the clutch in, let it slow and let it back out with some throttle and it came back. Then it happened again at 60 mph. So i slowed down to 50 and was fine. Due to this happening i decided to do the spacer mod on my bike and as well as turning the idle mixture screw two full turns from all the way in. I tried going 80 for a short time and did fine so i went on the highway. The same thing happened when i tried to go 80 for a longer amount of time except there was no pulsing of power or backfiring. I just heard a click and the engine started to die. I don't know what the hell is going on. Somone please tell me.

Read the post above. IMOO it is an electrical problem.
Check the items as described before.
As a thumper the Savage vibrates a lot, maybe your sidestand vibrates "loose" thereby interupting the ignition.
If putting the fuelc0ck to PRI solves the problem it's either the vacuum hose or the fuelc0ck membrane.
Greetz
Kropatchek

I would also check all the air lines coming off the carb. the one to the air box and the one to the petcock. also make sure the fuel tank is getting air through the cap. If starts dying, and you put it on Prime and it comes back, you almost certain have a starvation problem. the petcock has a diaphram in the back of it, you could check it out, just be careful, there's a spring in there that will get away from you in a heartbeat.