stoggy Posted June 23, 2008 Share Posted June 23, 2008 I just got a 77 xs400, it wont start. I am not much of a mechanic, but i figure i cant screw it up much worse then it already is. I decided to start with the carbs so took them apart, looks like they got sprayed with some kind of sealant to keep them from leaking, oh joy. when i took them apart I stuck my finger in them and raised the round cylinder things in the main tubes, and in 1 of them I could hear a thunk in the top. I got them apart and the diaphram isn't staying in place. When I raise the round thing the rubber at the top goes up too. So I cleaned them out real good, soaking in gas and a toothbrush/air compressor. When I went to put them back together one still seems ok, but on the other the diaphram wont stay in place so i cant really put the top back on, maybe with tape or something but that's ok. Is there anyway to repair the diaphram or do I need a new one? What could cause this problem? If i get a new one could the problem just smoke it too? I have seen carb rebuild kits on the web but they only seem to come with needles, springs and the bowl gasket. Do they sell aftermarket diaphrams, if so should i be searching for something other then diaphram? my is motocicle vocablary is very bad. Link to comment Share on other sites More sharing options...
theoben22 Posted June 24, 2008 Share Posted June 24, 2008 Hey Stoggy, your vocabulary is poor even for non motor sickle mechanic, the round things are known as slides or pistons as for carb parts try the link below if you are in the states. http://www.motorcyclecarbs.com/index.cfm Link to comment Share on other sites More sharing options...
mr benn Posted June 26, 2008 Share Posted June 26, 2008 are you saying that the diaphragm is detached from the silde? you need a new slide - it comes with the diaphragm attached. are you saying the diphragm won't stay in it's groove on the top of the carb? a smear of grease in the groove will hold it in place til you can get the cap on. Link to comment Share on other sites More sharing options...
stoggy Posted June 29, 2008 Author Share Posted June 29, 2008 are you saying that the diaphragm is detached from the silde? you need a new slide - it comes with the diaphragm attached. are you saying the diphragm won't stay in it's groove on the top of the carb? a smear of grease in the groove will hold it in place til you can get the cap on. Yea the diaphram wouldn't stay in the grove. I was having to stretch it to get it into that slot and it would pull itself out before I could get the top back on. grease didnt work. I fixed this though, a hair dryer and some stretching and now the carbs are working good. When I blow air past the top wide slot in the venturi tube, the cylinders raise up, and come down after wards. I also had to patch 1 of my floats but I think the carbs are good now. Unfortunately I took the alternator cover off and oil is dripping out, when I kick it oil pours out, another problem though. thanks. Link to comment Share on other sites More sharing options...
JimR Posted June 29, 2008 Share Posted June 29, 2008 Yea the diaphram wouldn't stay in the grove. I was having to stretch it to get it into that slot and it would pull itself out before I could get the top back on. grease didnt work. I fixed this though, a hair dryer and some stretching and now the carbs are working good. When I blow air past the top wide slot in the venturi tube, the cylinders raise up, and come down after wards. I also had to patch 1 of my floats but I think the carbs are good now. Unfortunately I took the alternator cover off and oil is dripping out, when I kick it oil pours out, another problem though. thanks. its over full I guess it runs out of the bottom screw hole... but they alway did on the side stand ! Link to comment Share on other sites More sharing options...
stoggy Posted June 29, 2008 Author Share Posted June 29, 2008 its over full I guess it runs out of the bottom screw hole... but they alway did on the side stand ! I dont know man I lost like a pint of oil but yea the bottom screw hole. it was on the center stand though. Link to comment Share on other sites More sharing options...
stoggy Posted June 30, 2008 Author Share Posted June 30, 2008 jimr i think you are right. I went out and checked the oil level and now it is perfect. I kicked it a couple times and no more oil is coming out. Link to comment Share on other sites More sharing options...
Cy Welch Posted June 30, 2008 Share Posted June 30, 2008 jimr i think you are right. I went out and checked the oil level and now it is perfect. I kicked it a couple times and no more oil is coming out. It will leak/drip oil out when the alternator cover is off. I will pour out if it's on the side stand. Except for setting timing etc, keep that cover on. Link to comment Share on other sites More sharing options...
WiCkY Posted July 10, 2008 Share Posted July 10, 2008 my diaphram wont stay in place i hope you don't fall pregnant did you finally get it fixed and running ok ? Link to comment Share on other sites More sharing options...
stoggy Posted July 16, 2008 Author Share Posted July 16, 2008 my diaphram wont stay in place i hope you don't fall pregnant did you finally get it fixed and running ok ? Heh, I hope it gets pregnant then I would have a new baby xs400. Maybe a xs250 or something? I got it starting but it will only run on full choke, half choke, or throttle at least 1/2 open with choke off. I guess i missed something in the needles? Could mis-calibration of the needles cause this? I installed an inline fuel filter and now I am hardly getting any fuel at all. Can't start. I am guessing take the petcock apart this weekend. Link to comment Share on other sites More sharing options...
Dave C Posted July 16, 2008 Share Posted July 16, 2008 Did you install the filter the correct way round. Link to comment Share on other sites More sharing options...
stoggy Posted July 17, 2008 Author Share Posted July 17, 2008 i did as long as the arrow points in the direction the gas is suppose to be going and not the direction the gas is suppose to be coming from. Link to comment Share on other sites More sharing options...
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