If you change the blinkers, make sure you change the flasher unit. These bikes have mechanical flashers and the LED's don't draw enough to trigger it. Also, the generator on the 550 is marginal compared to the load (don't know what you're riding...). The whole system is at a negative power draw until you hit 2K RPM or so (that's why you NEED the battery). Changing to an H4 will tax it somewhat, but likely offset by the other lamps. You may want to clean all those little bullet connectors to reduce the overall resistance of the wiring harness. There's lots of discussion regarding a swap to LED's with replacement flasher unit recommendations, instrument light thoughts (idiot = yes, LED & instrument = no LED). BTW, I'm running an H4 headlight, LED taillight, LED idiot lights & standard lamps elswhere.