Goldfinger Posted September 22, 2009 Share Posted September 22, 2009 After a few days of refusing to fire up, my XS400 slowly starts to show signs of life. After some confusion with wiring( thanks for your help, Drewpy!), I was still convinced the problem was electrical. Today I decided that it would run this week, as winter is fast approaching and there won't be many good riding days left. Checked a few posts on here to see where to start, and set about it. Thought I should start with the carb, left hand carb was fine, jets clean, opened up the right carb, the float was stuck and the rubber diaphragm ( is that what it's called?) was not seated correctly. Put it back together, checked the float was working smoothly, put it back on the bike. First turn of the starter, and she fired up. It ran for about 2 mins on full choke, then cut out. It fired up a few times more, but cuts out after 10 to 15 seconds, or as soon as I give it some revs. So it still needs some adjustment, but I'm well chuffed with the progress so far. Not to bad, considering it sat in the last owners back yard all winter, under a bush, at -30! I will now check the posts here for ideas on how to get it to run properly. I think a celebratory beer is called for! Link to comment Share on other sites More sharing options...
SirBieber Posted September 22, 2009 Share Posted September 22, 2009 I was in the exact same boat. Bought an '80 XS400 for $200 looking to make a nice cafe racer restoration project. At first it would fire up with the choke on. If I took the choke off it would die before it idled, and wouldnt start right after for atleast an hour. I had a buddy come over and check out all the electricals, and it turned out I had a bad solenoid. He tapped it a couple times, and it gave out more juice and now it fires up regularly, still need to replace with a more reliable solenoid though. I would suggest going through all circuits/fuses Link to comment Share on other sites More sharing options...
Goldfinger Posted September 23, 2009 Author Share Posted September 23, 2009 Tried her today when I got home, fired up on the button, without any choke. Ran for a good 10 mins, gave a few coughs and splutters when I reved her up, and also a couple of backfires, but on a whole, running much smoother than yesterday. Wasn't keen to start up a second time, but after I left it for 10 mins, started up again and ran for another 5 mins. The only problem now is fuel leaking from the right carb into the air filter box. I read on another post on here,(but I'm damed if I can find it now!) of someone else who had a similar problem, my question is- A. Why is it doing that, and B. How can I stop it. I know it needs some fine tuning regarding the mixture, I was wondering if that was something to do with flooded right carb? Link to comment Share on other sites More sharing options...
Goldfinger Posted September 23, 2009 Author Share Posted September 23, 2009 On my wife complaints of gas feumes coming from the garage, I just went out to check, and half a tank of gas has just flowed out the right carb onto the garage floor. I thought that if the petcock was in the on position, the gas flowed only when the engine was running? Is this correct? Or should to be in the PRI position when it is sitting? Any ideas as to what is wrong with the right carb? Any advice would be greatly appreciated. Link to comment Share on other sites More sharing options...
Moderator Airhead Posted September 23, 2009 Moderator Share Posted September 23, 2009 On my wife complaints of gas feumes coming from the garage, I just went out to check, and half a tank of gas has just flowed out the right carb onto the garage floor. I thought that if the petcock was in the on position, the gas flowed only when the engine was running? Is this correct? Or should to be in the PRI position when it is sitting? Any ideas as to what is wrong with the right carb? Any advice would be greatly appreciated. Your petcock is a vacuum operated type if it has a PRI (Read Prime) position. The Prime position should only be used briefly if the fuel has run out completely and the carbs are dry, normally the petcock would be used on th ON and RES (Reserve) positions only. For fuel to have leaked on to your garage floor this means that 1: The vacuum operated petcock is passing fuel 2: The RH carb float needle is also passing fuel ...Paul Link to comment Share on other sites More sharing options...
Goldfinger Posted September 24, 2009 Author Share Posted September 24, 2009 Your petcock is a vacuum operated type if it has a PRI (Read Prime) position. The Prime position should only be used briefly if the fuel has run out completely and the carbs are dry, normally the petcock would be used on th ON and RES (Reserve) positions only. For fuel to have leaked on to your garage floor this means that 1: The vacuum operated petcock is passing fuel 2: The RH carb float needle is also passing fuel ...Paul Hi, does that mean the seals in the petcock and/ or the carb are shot? Or does the float needle need replaced? When I removed the gas tank to drain it, with the petcock in the on position, there was a constant run of fuel. Does that indicate the seal is gone, or would it run as it is off the bike and there is no vacuum? This is all quite new to me, so please forgive any stupid questions! Link to comment Share on other sites More sharing options...
Moderator drewpy Posted September 24, 2009 Moderator Share Posted September 24, 2009 Hi, does that mean the seals in the petcock and/ or the carb are shot? Or does the float needle need replaced? When I removed the gas tank to drain it, with the petcock in the on position, there was a constant run of fuel. Does that indicate the seal is gone, or would it run as it is off the bike and there is no vacuum? This is all quite new to me, so please forgive any stupid questions! you can get petcock repair kits off ebay etc c/w new diaphram and seals. once you get that fixed, then see if the needle still leaks! drewps Link to comment Share on other sites More sharing options...
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