Dean01982 Posted October 17, 2020 Posted October 17, 2020 Hello everyone, I'm new here and to bikes so go easy.I have just bought a yamaha fazer 600 1999, I love the bike an all but I'm having issues with fuel running from the carbs, i think its coming from the float drain screws, if so where is the best to find replacements? And would these have o rings? Any other advise as to a fix or possible other locations the fuel could be coming from would be great.Cheers Quote
WD-40 Posted October 18, 2020 Posted October 18, 2020 Hello everyone, I'm new here and to bikes so go easy.I have just bought a yamaha fazer 600 1999, I love the bike an all but I'm having issues with fuel running from the carbs, i think its coming from the float drain screws, if so where is the best to find replacements? And would these have o rings? Any other advise as to a fix or possible other locations the fuel could be coming from would be great.Cheers There's no o rings on the drain screws. Did you check if the drain screws are tight? Most likely the problem is not the drain screws, it's the float valves not sealing and the fuel is dripping off the lowest point which is the drain. It could be the float bowl gaskets but that's less likely. A lot of the time the float valve and seat just needs a clean and they reseal. If cleaning doesn't work you can get after market rebuild kits from the likes of wemoto.com or you can get genuine Yamaha parts from fowlersparts.co.uk Quote
husoi Posted October 18, 2020 Posted October 18, 2020 It could be the float(s) being to high and too much petrol in the float chamber.The service manual should tell you the correct level for the floats.The adjustment is usually just carefully bend the metal bit that actions the float valve Quote
caveman Posted October 18, 2020 Posted October 18, 2020 It could be the float(s) being to high and too much petrol in the float chamber.The service manual should tell you the correct level for the floats.The adjustment is usually just carefully bend the metal bit that actions the float valve I would agree the floats are either set too high or they are sticking. Does it have a traditional fuel tap, if so check its not been left on prime as that could also cause the leak Quote
fastbob Posted October 18, 2020 Posted October 18, 2020 Hello everyone, I'm new here and to bikes so go easy.I have just bought a yamaha fazer 600 1999, I love the bike an all but I'm having issues with fuel running from the carbs, i think its coming from the float drain screws, if so where is the best to find replacements? And would these have o rings? Any other advise as to a fix or possible other locations the fuel could be coming from would be great.Cheers There's no o rings on the drain screws. Did you check if the drain screws are tight? Most likely the problem is not the drain screws, it's the float valves not sealing and the fuel is dripping off the lowest point which is the drain. It could be the float bowl gaskets but that's less likely. A lot of the time the float valve and seat just needs a clean and they reseal. If cleaning doesn't work you can get after market rebuild kits from the likes of wemoto.com or you can get genuine Yamaha parts from fowlersparts.co.uk Saved me the trouble . What he said , word for word . Quote
rightstuff Posted October 18, 2020 Posted October 18, 2020 had a similar problem on a honda was sure the drain screw was not sealing took the carbs of when taking off found the fuel hose had a small split and running down ànd dripping off the screw worth a check Quote
onesea Posted October 19, 2020 Posted October 19, 2020 As above but before you take things apart...Check for split hoses leading connections, fuel can travel a long way before it finds a place to drip.If bike runs you could try starting bike, running it till warm with Reddex or your favourite fuel additive might help.... Turning fuel off letting it run to stop, repeat a couple of times. If float valve is lazy or dirty in valve it might be enough to get it moving.Can you access the drain screw on the bowl of each carb? Unscrew gently to check for for of clean fuel from each Carb.Assuming fuel has of valve, turn fuel of drain each bowl. Close each screw and do same again.You could try fully removing agreed the drain screws and spraying carb cleaner up the screw hole. However getting screws in can be hard... Depending on access.Then look at taking things apart. Quote
WD-40 Posted October 19, 2020 Posted October 19, 2020 Another possibility is the o ring around the seat can fail. In that case even if the float valve is sealing and stopping the flow of fuel, the fuel continues to leak past the o ring. You can see the o ring I'm talking about here https://www.wemoto.com/bikes/yamaha/fzs_600_fazer/99/picture/carburettor_float_needleOr one more possibility is the springy part on the float valve that contacts the tab on the float can get stuck inside the float valve. Giving it a clean can free it up Quote
James in Brum Posted October 19, 2020 Posted October 19, 2020 My recent leak was a hairline crack in the float bowl. Quote
Dean01982 Posted November 7, 2020 Author Posted November 7, 2020 Hello everyone, sorry for the late reply, turns out it was the floats and shoddy work by the previous owner when trying to rebuild the carbs. Had a carb over haul and everything g is dandy now. Thanks for the replies chaps Quote
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