[Old Okie]

Before I begin to repair the stock tank for this 1979 CB400T, is there a tear drop style tank that is a bolt on. I really dislike this ugly, hump backed tank. My tank has some dents that are fixable and has some rust inside that is manageable but I really do not like this tank. What are my choices??? CM400???

 

[dtsmjr8dan]

You can use the teardrop tank off the CM400 I'm sure, but you will have a gap between the back of the tank and the front of the seat. If you pair it with a CM seat, it'll fit just fine.

 

[Old Okie]

That is good news, except that I just bought a good CB400 seat.
Maybe I can do some trading. Does the CM seat use the same mountings as the CB seat???

 

[longdistancerider]

Here's the list of tank sizes http://www.hondatwins.net/forums/67-miscellaneous-discussion/14103-fuel-tank-sizes.html
There are 2 versions of the front rubber pucks, narrow and 2 step. A narrow tank can be installed by cutting down the stud and puck so it's narrow. A wide tank can be fitted by tapping the stud and adding a short bolt and the 2 step puck. I don't know which tanks are what there.
The 78/79 CB rear mount point is further back than the CM's. That can be fixed by adding a piece of bar stock as an extension to move the mount point forward.
This is how the CB400 seat fits against the CM tank

 

[Old Okie]

That is not a bad fit.