My "rattle gun" is just a cheap Harborfreight gun, I can put lug nuts on with it but then it wont take that same nut off.  Can't remember it's max torque rating but I don't plan on putting it's max torque on it, just see if I can move it a bit more and pray - a lot

We have success!!!  With the cordless impact gun I gave it a quick three shots, with a piece of tape on the socket to see how far it moved, connected gas and battery, three kicks later she came to life.  The timing is only between 2.5 and 2.6 but after three hours of trying to get the 2.9 I'm going to call it good for now.  Thank all of you for your input and encouragement!

Glad it worked out! 

By the way, my cordless rattle gun isn't very expensive either, but it will break loose lug nuts torqued to 140 ft lb. However, as we've found out, if you're careful you can use them to torque the flywheel and clutch basket on these Yamahas.