Hi,
I'm restoring a 72 RT360, I'm taking the front forks apart to check and probably replace the seals etc.
Having followed the manual instructions to try and take out the Allen headed bolts at the bottom of the fork lowers so that I can remove the fork internals from the fork lower I'm having trouble actually removing the bolt.
I needed to use a little bit of heat to get the Allen bolt to move and don't think I was unduly forceful with it, just applied enough pressure to get it unscrewing (counterclockwise).
When I take out the oil drain screw and look into the hole I can see the bolt threads rotating as I turn the bolt but I am at a loss to figure out how to drag that sucker out of it's hidey hole!
What am I doing wrong please?

On other models with similar forks I've had the issue with the hex bolt rotating and the rod (technically called the piston in Yamaha documents) inside the fork that it screws into rotating along with it. With the spring and spacer removed and the fork collapsed I was able to use a large wooden dowel slid inside the inner fork tube to put pressure against the rod. Then I used a steel hammer to smack the allen wrench (short side in hex bolt) in the counterclockwise direction to break the bolt loose. I have read that others have used an impact wrench with success.

9 ways to get it out, what I do is leave the spring in and compress the fork so the spring holds the damper rod from turning, it was popular back in the day to use red locktite on the Allen bolt, (WHY?) if this is the case you may need to heat the bolt to get the locktite to loosen, k&L makes a tool that grabs the damper rod , I never liked the tool,.it has sharp edges that make metal shavings, loosen by hand if comfortable use an impact, impact is iffy it can round out the allen socket in the bolt, never used the broom handle method, plenty of folks have succeeded with the wood dowel, this is another job that the shop manual doesn't address , I've used the compressed spring method successfully for 40 years, if you round out the allen bolts socket, carefully drill.it out 

I re- read your post, what mauser said if it's just the bolt stuck on the washer

The internals other than the spring are still in place. It seems to be the whole internal mechanism is rotating as I turn the Allen bolt. Any tips on securing this?

How did you keep enough pressure on the dowel? I cannot seem to stop the damper from rotating.

Can you perhaps post or link me to a picture of the tool? Looking down the fork tube to the top of the damper it doesn't look the same as the video shows. There doesn't look like there is much to grab onto at all.

If it has the flats on the damping rod, a "gator grip" socket will grab it if you find/have one that just fits inside the tube. The 1/4" to 3/4" Gator Grip has an OD of about 25mm and has worked several times for me.  Not sure if it will fit the RT2 but you can measure the ID of the tube and eyeball the size of the end of the damping rod to see if the socket will fit inside and if about 3/4" is big enough to go over the end of the damping rod

Some models didn't have flats at all or Gator Grip didn't fit...  I grind a long shallow taper on a wooden broomstick or shovel handle that fits in the hole in the top of the damper rod and then hammer the tapered stick into the hole to grab it.  Electric or air impact wrench is very helpful. 

Here's a link to Gator Grip.  Local auto parts and hardware stores often carry the same/similar.
www.amazon.com/Original-Self-Adjusting-U...ation/dp/B0177E9JPS/


Here's a link to shovel handle with taper to give you an idea of what I was describing...  you will have to sand/grind/file/whittle the long taper to a smaller diameter that fits in damper rod hole if you start with a tapered shovel handle. 
www.amazon.com/Healvian-Gardening-Replac...ading/dp/B0C6ZHMKM2/

Not sure linking will go to plan with 20 photos.
Trying to retrieve some browny points for giving "Fake News" on dismantling.
Went & found my junk forks & dismantled.
After whizzing the bolt out with the 3/8 air wrench then the fun started.
Must be rust in the fork insides of the stanchion so pulled the circlip & slid the damper complete out the bottom end.
Or is it only meant to come out the bottom, not sure but i'll prove or disprove that point later.
Then just to show its possible i tapped a 16mm socket on which cut its own little marks.
So thinking if yours is turning then you're halfway there.
I used a half inch drive socket just because--no reason but is deeper than my 3/8 drive sockets.
Then i fitted a step down to use my long 3/8 T bar to hold it. Ok i already had it apart--but!!.
Plan was to actually try that trick in the other fork but couldn't get the cap off.
My methods of seal removal work for me but not recommending as is very thin around the top.
I heated with no luck but maybe impatient with the paint heat gun.
I then used a small chizel to angle tap the seal on the steel area to move it away from its housing but gotta be super careful & at a good angle inwards, & there's not much steel area to play with so don't touch the alloy housing.
I know guys have safer methods like a slide hammer & something expanding down in behind the seal.
I "have" or "had" then "lost it" the special factory socket to fit the top. So you can imagine how it looks looking at the damper top.
But thought seeing it's long lost it now puts me in your situation so better show how i'd react in such a situation.
While hoping not to break something lol.
Pics aren't in any particular order--i think.

photos.app.goo.gl/kmrbTYUjteWVE5ro8