Tuesday, December 2, 2014
In my effort to shed some weight, I've found that carbohydrates are my enemy. The other carbs, that bedevil me, are the ones that supply fuel to internal combustion engines. They are black magic. I understand the basic principle, but the finer nuances escape me. The Quadrajet, on my bike, has been a problem since day one. It used to flood when hot and restarts were difficult. I epoxied the plugs that tend to leak on these units and it seemed to work. It still never really ran right, so I sent it to a well known carb guy here in SoCal. It was much better, but I always thought it wasn't quite what it should be. A few years ago, I pulled it off and took it to an even more well known dyno tuner and he went through it again. Still, it wasn't what I had hoped for. It stinks when it idles and adjusting the idle mixture screws had no effect. I could turn them all the way in and nothing happened. I had the tank off the other day and while playing around, I noticed the primary throttle shaft was very loose in the carb body. Some Google searching told me that this is common in older, high mileage carbs. I ordered a st of repair bushings from Ninja Fuel Systems. They were 10 bucks. After getting the carb off and stripped down, it was necessary to drill out the holes in the carb body. A reamer is recommended, but I used a 3/8 drill and my drill press. Once the holes were enlarged, I tapped the bushings in with a brass hammer. When I tried to reinstall the shaft, it was too snug and wouldn't turn smoothly. I needed a 5/16 reamer, but I don't have one. I remembered an old trick. Take a length of 5/16 CRS or drill rod, if you have it. File one end at an angle about twice the diameter down the length of it and about 2/3 the diameter at the end. File as flat and as smooth as you can. The flat then can be honed on a stone. This will give you a pretty good, down and dirty reamer. I used it to align ream both bushings. The shaft fits very nice, now. The tiny 3-48 screws that hold the butterfly plates on need to be replaced. They are a one time use item. I had to order them from Fastenall. 8 bucks for 6 lousy screws. Oh well, at least I found them. They're not exactly easy to find.