How-to: Getting the generator rotor off with a bolt and spacer

[badguy]

I tried using a homemade slide hammer to get the rotor off, but it was on too tight (or the plate/washer I used at the end of the rod absorbed too much of the force) so it wouldn't budge.

     

I ended up using a strap wrench to hold the rotor still because the clutch was slipping when I tried to put it in gear and brace the back wheel.  Here's a pic of all the tools I used to do this, except for the jackstand:

     

Anyway, here's the way it went for me (sorry I don't have pics for everything):

1. Find a way to hold the rotor (ultimately the crankshaft) from spinning.  Before I got the strap wrench, I actually used a bent up coat hanger threaded through a hole in the rotor and tied to my case guard (the rotor already had a chipped magnet, so I wasn't worried about damaging it).  If you use the strap wrench, set it up as though you were using it to turn the rotor clockwise and snug it up to the rotor.  Put a jack stand or something else under the handle to keep it from turning.  Picture shown below is set up the opposite way, but demonstrates the idea:

   

2. Remove the rotor bolt (this bolt was TIGHT).

     

3. Find a 14mm fine threaded bolt (M14x1.5), I used one 45mm long, or about 1.75 inches.  I got it from a local hardware store, the big chains (Lowes, Home Depot) didn't have em...  By the way, this bolt has no shoulder, meaning it is threaded all the way to the bolt head - I think it's properly known as a set screw, but that's beside the point.

     

4.  Get/make a spacer to stick between the end of the bolt and the end of the crankshaft.  I used the shoulder from a 3/8" bolt.  I cut the head off and the threaded part off with a dremel and then smoothed out the ends.  It's about an inch and a half long (the guy on the left).

     

5.  Stick the spacer into the rotor and push it in until it bottoms out.

6.  Thread the 14mm bolt into the rotor until it's finger tight.

7.  Set up the strap wrench like in the first step but put it on as though you were turning the rotor counterclockwise.  The setup is shown below.

     

8.  Tighten the 14mm bolt until the rotor pops off, making sure the strap wrench isn't slipping.  It's probably a good idea to put some kind of padding on the ground below the engine for the rotor to fall onto.  If it's anything like mine, you'll just be straining against the bolt, and then BAM the rotor's on the ground. 

Now it's up to you to do your thing with the rotor.  Mine needs to be replaced (anyone have an extra one in good shape?) as well as the starter clutch components.  Hope this helps someone 

[SIKDMAX]

Great tip!

Now paint those engine guards 

[badguy]

Great tip!

Now paint those engine guards 

  Oh I will eventually...you should see the rest of the bike 

[The Buddha]

That was somewhat how my savage rotor comes out. Except instead of 14mm threads on the inside, it has 50mm threads on the outside. This clown's rotor was so tight that the tool I made cut a nice V notch in the end of the crank.
Cool.
Buddha.

[badguy]

This clown's rotor was so tight that the tool I made cut a nice V notch in the end of the crank.

yeah, this is what the end of the spacer/bolt shoulder looked like when I was finished:



damn, I forgot to make sure the bolt that holds the rotor on still threads into the crankshaft...

[astroaru]

thanks for the superb pictorial. I now know what to expect during my work-out. I have planned it for the following weekend. Will keep you guys posted on the progress.
PS: the final spacer's pic is funny, it says how much of effort was actually needed to get that damn thing off 

[sledge]

Something I find that often helps......when the bolt is tight against the spacer, hit the head with a hammer. The shock helps to break the taper, dont smack it as hard you can....... but it needs a fair old tap.

[badguy]

Something I find that often helps......when the bolt is tight against the spacer, hit the head with a hammer. The shock helps to break the taper, dont smack it as hard you can....... but it needs a fair old tap.

Thanks for the tip - I'll file that in for next time I'm up against something like this