I just install a flasher unit purchased on line and it works fine until I put some RPMs on the bike; then it won't flash or might flicker or just keep a steady on brake light;  it just will not deliver the four pulses per the advertisement. Back to bike idle speed and it works perfectly.

The supplier indicates two bench test were performed prior to shipping and directs me back to the installation sheet and offers no suggestions for a remedy.

I have seen other flashers that came with a diode. This supplier claims one is not needed. Something is going on when the RPMs are increased to cause the flasher to malfunction.

Can anyone help????   If a diode is required, how do I size it, then install it?

 Thanks for your help!

I was riding behind a bike yesterday that must have had the same device.  Every time he hit the brakes the lamps flashed 4 times then lit steady.  At speeed, with the clucth pulled in and the motor at idle does it behave as it should? 

have you checked voltage at the battery with engine revved a bit vs. at idle?