I pulled the magneto rotor using a special puller tool (took some doing, but it came off) in order to replace the starter overrunning/overriding clutch. Now I am trying to put it all back together, and I cannot seem to get the magneto rotor to go all the way back on. The spacer behind it has perhaps 1/4" of play. I've tried using the sleeve and bolt that screws into the end of the shaft to push the magneto rotor on, with no success. Perhaps my impact wrench is too weak?

Any suggestions / special tools / techniques that anyone has used successfully?

[2015 Z Force 800 53/Trail EPS]

I pulled the magneto rotor using a special puller tool (took some doing, but it came off) in order to replace the starter overrunning/overriding clutch. Now I am trying to put it all back together, and I cannot seem to get the magneto rotor to go all the way back on. The spacer behind it has perhaps 1/4" of play. I've tried using the sleeve and bolt that screws into the end of the shaft to push the magneto rotor on, with no success. Perhaps my impact wrench is too weak?

Any suggestions / special tools / techniques that anyone has used successfully?

Woow..slow down. The rotor should go back on within a few thousands of where it needs to be and the retainer with the proper torque should be enough to seat it properly. Look at it closely...it's not on backwards is it...and other parts missing, key in correctly? Shoot some pics and post them...let us see it.

Here are a couple pictures. As I said in my prior post, using the puller tool it was very hard to pull the magneto rotor off. Getting it back on is very difficult. I'm probably 1/8" from where it needs to be, and the fan sleeve and bolt, using torque well in excess of recommended, won't pull it further into place.

[2015 Z Force 800 53/Trail EPS]

I can't see everything...sorry, wish I could help. Pull it all back off and inspect closely.

Thanks for your advice. I pulled the magneto rotor again, didn't see any problems, i.e. the shaft was clean. I used some WD-40, put it back on, and cranked on the sleeve bolt with an air wrench, with probably a lot more torque than the 40 lbs specified, and lo and behold, the magneto seated far enough that I felt it was within tolerances. I put everything back together and it ran like a champ. Thanks again!

[2015 Z Force 800 53/Trail EPS]

Thanks for your advice. I pulled the magneto rotor again, didn't see any problems, i.e. the shaft was clean. I used some WD-40, put it back on, and cranked on the sleeve bolt with an air wrench, with probably a lot more torque than the 40 lbs specified, and lo and behold, the magneto seated far enough that I felt it was within tolerances. I put everything back together and it ran like a champ. Thanks again!

That IS good news.

Good news. There has been many times I have taken apart something that isn't working right, didn't find what was wrong, and reassembled it only to find that it now works and I have no idea why.
I unashamedly take credit for something anyway. 
Take care, hope it's up and running.