I have been working on a little cafe/solo seat project since October and it is very close to completion. This is my first big motorcycle sheetmetal project, so I have been taking my time. I have been waiting to drop the hammer on this thread so as not to be a project tease. I hope it was worth the wait.
I started with the factory 750 K4 seat pan and used a tank from a CB350 twin as the seat cowl. The tank was graciously donated by fellow forum member CBGB's, thanks Kyle. The tank was rusty, perforated, and begging for a new life.
First I cut out everything in the way of setting the shell over the seat.
Next, I cut off the front of the tank in the shape I thought I wanted.
I am a little short on photos for the next few steps but I spent some time aligning the tank on the pan, and figuring out what final lines I was looking for. I used a sheetmetal screw at the forward bottom point of the shell as a pivot point for fitment. I would pivot it down, check the fitment, lines, and obstructions, then mark the areas needing attention. I would then pivot it forward to shape and file, then pivot back, etc. Once the fit was good around the fender I used six #40 clecos to attach the tank to the seat pan. Once it was attached, I opened the seat from the side and checked fitment and obstructions going sideways. I used a french curve set to come up with a shape I liked for the curves coming from the sides going up and around the fender. I planned to ditch the grab rail and install shorty turn signals in the grab rail bolt holes so I allowed room for those.
I had the shell welded to the pan and moved on to the tail light.
I used a Lucas style taillight to fit in to the rear of the cowl. I took a piece of 18 gague steel and bent it around the taillight base, then marked the inside of the tank with the outline. I wanted the aft end of the light nearly flush with the back of the cowl so I measured several times prior to cutting the area out of the tank. Once everything was set, it was welded in.
Once I was set on the tail light positioning, I cut a piece for the butt stop and welded it in.
I wanted to use the space created by the new seat cowl so I cut an access hole in the seat pan.
The next steps were all of the finish filing of the bottom and top lines, filling, sanding, and filling.
Before I turned it over to my paint guy, I figured out the seat foam arrangement. I am 6'4", 230 lbs., so padding is required. After one failed foam attempt, I found this stuff called Aquamat at a local upholstery shop. It is 1" thick, so I ended up with two and one half thicknesses of it bonded together. I did a lot of sit testing to figure out what needed to be carved off. I used a sharpie and a turkey knife and went to town. I did a little bit more foam work after I took this next photo, but this is the basic arrangement.
I fixed the cracks in the side covers and filled in the relief for the "750 Four" badge with Metal Set A4.
I did not do the paint, luckily I work with a guy (that paints airplanes for a living) who does very nice work. I started out wanting a candy color and liked the oranges, but my buddy had some Fusion Orange Metallic (late model GM color) at his disposal (read FREE). I wanted it a little lighter so he added silver pearl metallic and some more flake for me. Did I mention I have very little money in to this project?
This is what I ended up with.
These last photos were taken the day I got my painted parts back. I am pretty pleased so far. I was trying to decide whether or not to ditch the fender, since I wasn't sure I liked the look. I decided to cut another inch and a half off of the front and remount it. I will post some more photos this week when I (hopefully) get my finished seat cover back and installed.
