May I Put The Other Bike's Fuel Tank On Street Twin Directly?

The answer is no and no.

 

Gakki
No again. Not the old days anymore. The old T140 Bonnies and others you used to swap tanks regularly. But of course if you are ingenious you could fit anything. But it might cost more than its worth. Do hit the upload a file button bottom right corner and show of your steed
Joe

 

Middle cylinder? How many cylinders you got on that thing?

 

Gakki.
And again are you sure you have a Street Twin not a street triple. As its in the name twin. Two cylinders.
Joe.

 

The pictures on earlier posts clearly indicate the bike is a street twin. I think he means that there is a hole in the barrels i.e. the middle part of the cylinder.