I completely underestimated how difficult the motorcycle rebuild would be when I got into it. This is a short list of things you can expect to do.
To set the stage, when I purchased the CB, one of the pistons had blown from overuse of starter fluid. As a result, there was a hole in the piston and little chunks of piston were all throughout the engine. When I did take the lower end of the engine apart, I saw all of these. They were everywhere, at the bottom of the case and in the oil pump screen. Luckily, there was no damage to the transmission or any of the other lower end parts. The cylinders were also clean. This is a total stroke of luck because I wouldn’t have known what I was looking for when I purchased the bike and to check for damage that this might have caused.
OK, so some items you’ll expect to do:
- Engine – remove, disassemble, inspect. Expect to change the oil seals, rubber components, gaskets, and chains at a minimum. The inspection should find other parts out of spec. I had to change the bearings between the crankshaft and the engine case as well. Because a piston was blown, I had to replace all four. In doing so, I chose to upgrade the displacement from 750cc to 836cc. This required boring out the cylinders. This is another thing I would have had to do anyway, because the cylinder dimension was out of spec and required me to go to the next largest cylinder size (.25mm+) from the previous piston.
- Oil Pump – remove, disassemble, inspect. Expect to change all rubber components (o-rings, etc.).
- Carbs – remove, dissemble, inspect. Expect to change some components. Best to purchase a kit for your particular motorcycle. For the CB750, 4into1, Vintage CB750, and CB750 Supply are really good choices. You’ll have to make sure to adjust the floats to their proper spec when finished.
Please follow the Shop Manual. It’s easy to get overwhelmed. Take it one section at a time.
You’ll also need to find a good machine shop. Things like cylinder re-boring, valve work, and aluminum welding are best done by a professional. Just as a shout-out, the guy I use in San Jose, CA is exceptional. FFR Fabrication. 5 out 5 Stars on Yelp!
This will be an on-going post, I’ll continue to update as I get to additional sections. Hopefully, one day soon I’ll actually get to talk about ascetics and style.