CB750F Project: part I

I found her sitting in the front lawn of a house next town over. Neglected by her previous master, the old man who put her in front of his house took her home two weeks earlier. Maybe things between them did not work out as he had imagined they would...maybe it was a matter of personality. I'll never know. Either way, he thought she was too much for him. I knew there and then that I had to save her.
 
Friday, after lunch, I brought her home. Dust covered, she sat on the trailer, strapped down in a way no self-respecting old lady would ever want to be seen in public. Still, she did not complain.

As I walked around her running my fingers along her once smooth lines, I felt the wrinkles age engraves in everything in this world. She stunk of old rubber and bad gas, but her allure was still there...just under the surface, begging to be discovered. Yet, bastardly as it was of me, I left her there waiting for me until the evening.

Little did I know I was going to pay for my selfish attitude. Perhaps she got jealous of the younger ones she saw in the garage,  or perhaps she just didn't care for me leaving her there all day. Either way, she gave me a nasty gash when I was trying to bring her down from the trailer. I sat on top of her and untied the first strap. Suddenly, she bucked to the side and threw me off. I had just enough time to jump to the side before she could land on me. Seeing this, she fells faster and landed on my ankle, pinning me down against the trailer. Full of adrenaline, I wiggled my foot free, grabbed her, and stood her upright. She hasn't tried to do that since.

So, let me introduce you to her, a 1980 CB750F Super Sport.

The motor ran, but only on three cylinders. My initial thought was to save this project for the long winter ahead, but the mysterious running issue kept bothering me. I knew I had to dive in and work on it.

I checked spark, fuel, and all seemed to be there. So I took the carbs and the airbox out, and proceeded to clean the carburetors.

It turns out that someone installed one float upside down. Still, while at it, I cleaned all jets and passages, tightened all screw, and soaked gaskets in brake fluid. Then I put it all back together (except the airbox which had the wrong filter element inside).
Upon starting, all four cylinders came alive. I'll have to wait for a full adjustment until I get a new air filter, but for now the faulty cylinder issue has been solved.

There are a couple of things on this bike that are just plain wrong. namely the seat and the handlebars, but there are many more issues I'll need to work on.

I took the seat off, stripped the upholstery and foam, and discovered that I don't like the shape of the pan. Since this bike is not exactly a cafe-racer (although it can be made that way), I decided against the traditional cafe seat in place of a comfortable, low seat. My initial thought was to make my own pan (here is another first one), but after seeing the lines, bends, and curves in the fender and seat area, I decided to try something else. Since my KLR250 Project, I've had a spare KLR seat sitting on the shelf. I took the foam off and tried fitting it. Yup, with a little modification it could be made to work. I like the way the KLR seat comes up against the tank, and follows through. The pan has to be bend a little, curved a little, and cut a little, but it should work. For the fitting, I bolted the pan thought to the battery box up front, and the fender bracket in the rear.

There is a little shaping involved to follow the lines of the battery covers.

And I still have to figure out what to do with the rear section. I'm thinking fiberglass, and a lots of shaping.

For now though, I'm excited even about the possibility of having a custom-made seat from an old KLR seat. Who would have thought.

This project may take some time. After all, the summer is here and I have two bikes that need to get out every now and then. But I'll keep you posted.