I am looking for an Yamaha special tool # 90890-01034 Armature puller. I would like to buy one or get the dimensions of the tool to build one.
I know they are 3/8" standard size thread, but need the length of the solid pin to make one. Any help would be appreciated. Rod

I need a tool to pull the armature off my '76 DT125 to inspect, clean, etc 

Thanks

If you can see the end of the crank looking in the armature, then the pin will need to touch down in the end of the center hole & be long enough to protrude a little to stop the end of the bolt getting burred against the crank end. Its quite a common puller i think & probably the same one used over the years on all the electric start armatures even the twin cylinder ones.. But incase i'm wrong & thread changed i hope someone corrects me. Yamaha even suggest using a slide hammer in my AT1 book if you had a bolt to thread in but didn't have the proper long pin one. Bolt looks like this random one if the link will work.
m.siriusconinc.com/products-detail.php?product_id=122688