I have a problem that I'm looking for some suggestions with. I have a 1985 Yamaha XJ700 it had a 4 cylinder engine with 4 carbs. I am the original owner and the bike only has 8000 miles on it. It is leaking fuel all over the floor. It has done this twice before but both of those time it was when I needed to move it in the dead of winter and it was freezing cold so I just figured something was forzen open, this time however it is in warm weather. The fuel overflows into the breatherbox and then when it get full enough the fuel runs into the vent hole that goes into the crankcase. Both of the times it happened before I made sure I changed the oil before running the bike. I'm not an engine expert by any means but I am trying to find out what someone who does know engines for their thoughts on what could be getting stuck open that would allow fuel to run out like this. Also is this anything I could try doing myself before taking it the dealer to have it looked at. I have no problem with taking it somewhere but unfortunately the shops near me do not have a great reputation and I thought I would ask for some suggestions first.
Looking for cause of fuel leak.
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Thanks.....I would love to be able to shut the fuel off but unfortunately the pet**** has no off position. Just On, Reserve, and Prime. Well anyway I drained the tank and the crank and poured a Qt of fresh oil in the crank. I have an appointment at the yamaha dealer this week. I hope its just a cleaning thats needed.
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fuel valve
I know that it is a little late for a reply but I just read this post. The problem here is not the carbs but the fuel valve. Yamaha in all their wisdom thought that a vacume valve on the fuel system would save all of the bother of turning the fuel off and on every time you used the bike. The problem is that these valves stick, gum-up or the diaphram gets old and weak. The fuel then keeps dribbling into the carbs and the carbs overflow. You can rebuild the valve or just replace the whole thing for about $75.00.
I know that it is a little late for a reply but I just read this post. The problem here is not the carbs but the fuel valve. Yamaha in all their wisdom thought that a vacume valve on the fuel system would save all of the bother of turning the fuel off and on every time you used the bike. The problem is that these valves stick, gum-up or the diaphram gets old and weak. The fuel then keeps dribbling into the carbs and the carbs overflow. You can rebuild the valve or just replace the whole thing for about $75.00.
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