1980 GS550E frame differences: What do I have here?

[Guest]

I have a 1980 GS550E and I'm transplanting late model GSX750F engine, suspension, etc., into it. That left me with the stock GS550 engine, suspension, wheels, etc.
OK, I'll get online and find a titled frame and build a bike from the leftovers!

Searched eBay for a while, being careful to not get an L frame. I knew the rear tank mounts were different, the seat frame area was different, etc. I came across a "1980 GS550E frame" and it appeared to have the correct rear tank mount in the pics. Bought it and, later on, when trying to fit a tank, noticed that something wasn't right. At first, I thought I was sent a 750 tank by mistake. But the more I look at it, I notice that the tank mounting points are different.

Both frames have a "GS550E-XXXXX" VIN number, with matching titles. Both are 1980 build dates. Look at the pics below. What do I have and what is the correct tank for the "cafe" frame?

Forward mount of the standard 550E frame. I bought this as a complete bike with bodywork, etc.



Forward mount of the eBay "cafe" frame. The nipples for the tank grommets are higher and further back.



Rear tank mount of the "stock" frame.



Rear tank mount of the eBay frame. See how it sits higher and further forward?



Overall comparison of the two.




Another pic of the forward tank mounts. The coil mounts are different, too.

 

[scratch]

It is an L. 1980 L frames are stamped 550E, my gal's is anyway. I'm pretty sure her forward tank mounts are also up on the backbone like that too... I'll pull it later to doublecheck if you need confimation.

 

[Steve]

Not just the '80s. :-k I think Cowboyup's '81 550T and his daughter's '81 550L are also marked with an "E".

.

 

[Guest]

Well, crap. I specifically got it because it was labeled "E". I think I can make it work. It's going to be a custom anyway, with all the leftover parts. The rear has been hacked and an electrics tray has been installed. A stalled "cafe" project.

 

[scratch]

Well, crap. I specifically got it because it was labeled "E". I think I can make it work. It's going to be a custom anyway, with all the leftover parts. The rear has been hacked and an electrics tray has been installed. A stalled "cafe" project.

You can grind off the upper mount and weld a post in the "hole" where the E tank post should be. The hole goes right through so it's easy to square up one post that goes right through...

 

[Guest]

That's sort of the plan. I was going to use threaded rod and lock nuts to make new pegs for the tank rubber.
A spacer and longer bolt at the rear should make that mount fit.