I am bringing a 73 RT3 Yamaha back to original or as much as possible.
The gas tanks I have for the bike are for that bike however as i look into parts diagrams for this year the tanks appear to show a small metal tab at back of tank with a bit of a curl to it, Also the diagrams show a rubber block and and rubber band.I am not sure if both of these would make up the original fastening or not.
Both of my tanks do not have the metal tab at the back. Just wondering if I will have to fab something before i repaint tank..?
Would any one with an RT3 be able to explain how tank should attach as intended from the factory and in relation to these rubber fastening parts, block and the band.
Appreciate any help on this
 

The original tanks had a "hook" tab on the back that the band hooks over.  Odd that you have two that have tabs missing...  I've seen the tabs bent up but never missing.  

Pics would help.  Maybe you only think you have correct tanks? 

 

yes quite possible, will do some more work at this end, if I have to I will fab a tab.
thx

I wouldn't worry about it - it will be a very unusual set of circumstances needed for the tank to fly off.

Actually, I was wanting to ask a question related to this post. On the 1972 Yamaha 360 RT2 where does the fuel tank damper locating rubber piece set and what holds it on the frame.  I took my tank off and it fell off. 

have you ever seen the bent up tabs brought back to an unbent, nicely curved status? I'm in the "tab bent up" camp and am not wanting to break it off if I try to bend it back.

#5 Can't go wrong with the rubber piece, it just sit where the frame tapers off & sits naturaly there then tank snugs down on it. I 'do' think the tank tab is good to have to hold down with a heavy rubber band or the correct rubber thingy. Without that i think i'd fit a pad of something under the front end of the seat to put slight force on the tank to keep it secure & help vibration. But be careful to 'not fit the rubber too far forward' & end up with the tank touching the frame at the rear edges.