Got my '06 ltr fixed finnallllyyy!! I haven't been able to start my quad for almost a year and was worried I would have to spend too much money in the shop to get her fixed. I took it in and found that the key way was worn down and not engaging the starter clutch. I had the starter clutch replaced before when I had the same problem; it started fine for the next 4 or 5 rides and went back to the same thing.
The tech at the shop told me that hitting the throttle while starting the quad can wear down the key way to the point where it won't engage the starter clutch. I know for a fact it wasn't something I did every time starting it up, but can't honestly say I've never done it. He said the Hondas are BIG on having this happen, and they actually have a warning about it. I also have a high compression piston which he said will make it harder to try to crank, which makes sense. Just wanted to give warning to riders: Don't hit the gas while hitting your electric start!
Btw: Total cost to fix the key way: $145.00!
Big shout out to Team Powersport of Smithfield, NC for doing the work