#cb700

Step 1: Tear-down

First things first I had to pull the bike apart to be able to get to everything I needed to fix and evaluate. My laundry list of projects was as follows:

Flush and clean the tank Rebuild the carburetors Replace the aftermarket pod filters with the OEM Airbox and hoses Replace vacuum and gas lines Flush and restore the brakes Change the oil Replace all the lights with brighter modern LED lights Replace the worn rear tire

Having worked on cars I assumed that each of these tasks would spawn their own set of sub-tasks. I was not mistaken (hence the beer).

Step 2: Frankenstein’s Monster

Having the pod filters actually made it easier to pull the carb, but did mean I had to drop some money on replacement hoses to mate the carb intake manifold to the airbox (which luckily hadn’t been removed). Pod filters are an affectation of the cafe racer scene and they’re fine for some bikes, but they looked terrible on this one and whomever installed them didn’t rejet the carbs to account for the difference in airflow. 

This is why you clean your carbs kids. This was the worst of the sludge that had accumulated in the bowl of the carb, but they all had deposits of varying degrees. 

The choke valves were also a total mess. This one was seized in the carb body and took some convincing to get loose. Once it was cleaned up and back on the bike we were in business though. 

A post shared by Dave Beaudoin (@daswickerman) on Jul 1, 2017 at 12:25pm PDT

It’s Alive!

Step 3: Fluids are boring

I changed the oil, and flushed the brake lines with a handy vacuum pump. I will say that the whole process is way easier when you’re working on a 500lb bike and not a 1500lb car!

Step 4: Electrical

With old vehicles it’s not uncommon to have electrical “gremlins” that you have to chase down. I converted everything to LED lights and updated the original flasher unit from an electro-mechanical model to a pure electronic flasher. That upgrade is necessary because LED lights don’t draw enough power to operate the magnets inside an old style flasher and you end up with no flash or fast flashing. It’s a similar situation as to what you used to see on vehicles with trailers. Attaching the extra wiring to the system changes the current and resistance and no longer matches the specs of the flasher. Electronic flashers fix this by only requiring a very minimal current to operate. They’re far for forgiving and for $6-$10 deliver great results. 

Once the conversion was done I was still having problems with my brake lights and headlight. After about a week with a multi-tester and the wiring diagram for the bike, I found one of the problems. A broken ground contact in the light switch was disabling the headlight. Since I had it out of the bike, I rebuilt the switch and added solder to the contacts on the inside of the mechanism to replace copper that had worn down. Once that was sorted I was treated to this ridiculously bright headlight! Score one for safety!

The other issue is with the break lever on the handlebar. It’s an aftermarket lever and lacks the material to properly push down the leaf switch that controls the rear brake light. The options here are to find an original replacement or build up that part of the brake with extra material. I’ll probably take the latter approach in the short term by using JB Weld or another epoxy to build up the lever while I look for a more suitable replacement.