Maybe. I have seen 7 amps used in a 750. You can leave in the electric start but you most likely will not be able to use it as the motor will pull to much to allow the coils to charge properly, or saturate, if you are anal retentive.
You can use it to test lighting to make sure it works.
But if you are not riding with it, I don't see why it couldn't be used for testing.
However, if your bike is hard to start, the battery will go flat fairly quickly.