First Ill say I'm new and thanks for letting me join. I'm a fairly handy guy and race karts on the weekends with the kids. This is a a new hobby I have been exploring and finally found a bike/bikes that fit the mold.
I bought a 79CB custom. It was modified some before I got it and had carb and some aesthetic work done. Drag bars, lights, mirrors all new and extra with the bike. Also got chain, carb kits and other misc stuff. The bike was running when I bought it as well. It does leak oil, but the engine sounded smooth and doesn't smoke. I recently drained the fuel from the carbs and used new fuel to start the bike. It didn't want to run and so I decided Id take the carbs off and clean them. It was all common to me as the karts we run use a similar carb and we clean those almost every week (dirt racing). I'm glad I decided to clean the carbs as they had a ton of crap in them, rust, sand, dirt... and it looks like the guy I bought it from used ethanol fuel as well. Not sure if it matters but I always try to run non-ethanol in my small engines, mowers, etc.
During disassembly I noticed one of the "puck" seal rings was missing. Not sure why, but its gone. I cleaned everything else, making sure all passages are clean, jets, and holes, and more jets, and under the kidney looking guide plates.....and so on. Everything came clean and looked good enough to put back together. I know the seal ring needs to be replaced, not sure where to get one yet. If anyone has a suggestion that would be great.
Put new fuel in the tank, non-ethanol, and let the bowls fill up. No leaks, and I checked the drain screws for fuel across the assembly. With a couple cranks and some starter fluid the bike fired right up. Sounds great and I let it idle a little before checking the throttle. Hit the throttle and it seems to have a delay. So I knew some more work to the carbs is needed. After a couple more mins I hit the throttle again and the it seemed like it stuck. Rpm ran high an I couldnt do anything to get it to idle down. I turned the bike off, and restarted it and the idle was down again. Hit the throttle and it stuck again, but the plates dont get stuck. So know I'm thinking it has to be in the carbs somewhere...vacuum leak or some other passages I didn't get completely clean.
I thought back to the seal ring under the puck and wondered if that could cause this. Then I found out about the accelerator pump and vacuum cutoff diaphragms. So I will need to take those apart to see how dirty they are. Once that all clean and put back together I will find out how the motor runs. I checked a few websites for carb kits but they seem to be out stock. Does anybody have a good place to buy kits?
In the mean time. I also have an '81 CB750 Super Sport. I bought it as a parts bike due to the bike having a title issue. The bike has 6800 miles on it. And is complete, all original. I learned later that I can title the bike via court order. Just need to dish out a firm 300 to get it done. So I'm not sure if I'm going to use the bike for parts, or sell it... opinions?
I bought a 79CB custom. It was modified some before I got it and had carb and some aesthetic work done. Drag bars, lights, mirrors all new and extra with the bike. Also got chain, carb kits and other misc stuff. The bike was running when I bought it as well. It does leak oil, but the engine sounded smooth and doesn't smoke. I recently drained the fuel from the carbs and used new fuel to start the bike. It didn't want to run and so I decided Id take the carbs off and clean them. It was all common to me as the karts we run use a similar carb and we clean those almost every week (dirt racing). I'm glad I decided to clean the carbs as they had a ton of crap in them, rust, sand, dirt... and it looks like the guy I bought it from used ethanol fuel as well. Not sure if it matters but I always try to run non-ethanol in my small engines, mowers, etc.
During disassembly I noticed one of the "puck" seal rings was missing. Not sure why, but its gone. I cleaned everything else, making sure all passages are clean, jets, and holes, and more jets, and under the kidney looking guide plates.....and so on. Everything came clean and looked good enough to put back together. I know the seal ring needs to be replaced, not sure where to get one yet. If anyone has a suggestion that would be great.
Put new fuel in the tank, non-ethanol, and let the bowls fill up. No leaks, and I checked the drain screws for fuel across the assembly. With a couple cranks and some starter fluid the bike fired right up. Sounds great and I let it idle a little before checking the throttle. Hit the throttle and it seems to have a delay. So I knew some more work to the carbs is needed. After a couple more mins I hit the throttle again and the it seemed like it stuck. Rpm ran high an I couldnt do anything to get it to idle down. I turned the bike off, and restarted it and the idle was down again. Hit the throttle and it stuck again, but the plates dont get stuck. So know I'm thinking it has to be in the carbs somewhere...vacuum leak or some other passages I didn't get completely clean.
I thought back to the seal ring under the puck and wondered if that could cause this. Then I found out about the accelerator pump and vacuum cutoff diaphragms. So I will need to take those apart to see how dirty they are. Once that all clean and put back together I will find out how the motor runs. I checked a few websites for carb kits but they seem to be out stock. Does anybody have a good place to buy kits?
In the mean time. I also have an '81 CB750 Super Sport. I bought it as a parts bike due to the bike having a title issue. The bike has 6800 miles on it. And is complete, all original. I learned later that I can title the bike via court order. Just need to dish out a firm 300 to get it done. So I'm not sure if I'm going to use the bike for parts, or sell it... opinions?