I have a 1980 gs550.
I am annoyed with the vacuum diaphragm operated petcock! It has been causing me problems for a while. First of all, the "prime" setting on the petcock does not work. This means that every time I have to take off and empty the carbs, I have to simulate the vacuum action with a syringe to fill up the reinstalled carbs. Not only this, but now my gs550 starts really hard. Once it gets going, it is just fine. I'm pretty sure that cylinders 1 and 2 are not firing right away. It also smells like gas when I first start it. I am theorizing that fuel may be leaking down the vacuum line in small amounts while it is sitting and flooding either cylinder 1 or 2 or both. Why did they make this overly complicated system? I understand that the fuel is still gravity fed, and the vacuum diaphragm acts as a fuel shut off when the bike is not running. Why cant I just take out this vacuum system and have the fuel gravity fed. I would install a fuel switch to shut off the fuel every time I was done riding the bike. I don't see why this wouldn't work. Isn't that what the float valves are supposed to do? Won't they regulate the amount of fuel going to the carbs? I'm seriously thinking about doing this. I would like some input whether this is a good idea or not. Is there another function of this vacuum system that I am not thinking of?
I am annoyed with the vacuum diaphragm operated petcock! It has been causing me problems for a while. First of all, the "prime" setting on the petcock does not work. This means that every time I have to take off and empty the carbs, I have to simulate the vacuum action with a syringe to fill up the reinstalled carbs. Not only this, but now my gs550 starts really hard. Once it gets going, it is just fine. I'm pretty sure that cylinders 1 and 2 are not firing right away. It also smells like gas when I first start it. I am theorizing that fuel may be leaking down the vacuum line in small amounts while it is sitting and flooding either cylinder 1 or 2 or both. Why did they make this overly complicated system? I understand that the fuel is still gravity fed, and the vacuum diaphragm acts as a fuel shut off when the bike is not running. Why cant I just take out this vacuum system and have the fuel gravity fed. I would install a fuel switch to shut off the fuel every time I was done riding the bike. I don't see why this wouldn't work. Isn't that what the float valves are supposed to do? Won't they regulate the amount of fuel going to the carbs? I'm seriously thinking about doing this. I would like some input whether this is a good idea or not. Is there another function of this vacuum system that I am not thinking of?
