paulebble Posted October 20, 2023 Share Posted October 20, 2023 Hi everyone, im a newbie to the forum. I am trying to help my son sort a problem on his 2012 Yamaha XT125X. the fuel valve (electronic) was leaking and after much searching I managed to find a new one. It looks the same as the one that was removed. After I installed the valve the bike will not start. I’ve checked and it looks like there’s no fuel getting through the valve to the carb? Has anyone had this problem before? Or can anyone give me any ideas what to check. I’ve checked the fuse and it is good, on the old valve I tried to blow through both of the tubes coming off it and they don’t allow any air through. But in the new valve I can blow air through both tubes? I tried starting the bike with the tubes from the valve disconnected and no fuel comes through. I can’t install the old one to try this as it leaks from the body of the valve. I have attached a pic of the old valve. any help or advice is welcomed. Quote Link to comment Share on other sites More sharing options...
Isla Posted October 20, 2023 Share Posted October 20, 2023 Is the wiring plug connected fully & can you hear the valve operating when you switch the ignition on? (And please don't be insulted, but I always go back to basics with techy probs - kill switch? kickstand? battery not gone flat?) Quote Link to comment Share on other sites More sharing options...
paulebble Posted October 20, 2023 Author Share Posted October 20, 2023 13 minutes ago, Isla said: Is the wiring plug connected fully & can you hear the valve operating when you switch the ignition on? (And please don't be insulted, but I always go back to basics with techy probs - kill switch? kickstand? battery not gone flat?) Hi, thanks for the reply. No offence taken. All advice is welcomed. The plug is fully inserted. The side stand up, in neutral (and pulling clutch lever), kill switch is In correct position and battery fully charged. Though I can’t hear the valve operating when I switch the ignition on. I’ll double check again when I get a chance. Quote Link to comment Share on other sites More sharing options...
RideWithStyles Posted October 20, 2023 Share Posted October 20, 2023 (edited) Normally they are a vacuum pressure to let the fuel through. then when no pressure is evident they close shut so they dont leak. Hence why the old failed unit just leaks. Are these new one actually new or second hand?? have you connected the pipes the correct way round? So one will need to suck the valve open (giggity) while the other will let it out to the carb. Edited October 20, 2023 by RideWithStyles Quote Link to comment Share on other sites More sharing options...
paulebble Posted October 21, 2023 Author Share Posted October 21, 2023 11 hours ago, RideWithStyles said: Normally they are a vacuum pressure to let the fuel through. then when no pressure is evident they close shut so they dont leak. Hence why the old failed unit just leaks. Are these new one actually new or second hand?? have you connected the pipes the correct way round? So one will need to suck the valve open (giggity) while the other will let it out to the carb. Hi, The hoses are 6mm and 10mm so only go on one way. The valve is new. I cannot feel or hear anything at the valve when I turn on the ignition or when trying to start the bike. I did suck on the vacuum tube and the petrol flows from the supply tube. I can feel a little vacuum at the carb vacuum port but it’s maybe not enough to operate the valve. 12 hours ago, RideWithStyles said: Normally they are a vacuum pressure to let the fuel through. then when no pressure is evident they close shut so they dont leak. Hence why the old failed unit just leaks. Are these new one actually new or second hand?? have you connected the pipes the correct way round? So one will need to suck the valve open (giggity) while the other will let it out to the carb. I have just attached the vacuum hose to the valve and ran a hose from the supply pipe to a container (in open air) and turned the engine over. I only got a small amount of fuel coming out, not a constant flow? Could this be a carb problem? Quote Link to comment Share on other sites More sharing options...
Bianco2564 Posted October 21, 2023 Share Posted October 21, 2023 Just thinking about how the valve works, not familiar with them. Is the electrical connection a priming function, turn ignition on or crank it and 12v is sent to the valve to flow fuel? Once the engine starts, the intake vacuum takes over? Can you bypass the valve and just connect the carb straight to a fuel supply and check the engine runs.? Check what the 12v supply does when you switch the ignition on. Check that the valves earth is good. 1 Quote Link to comment Share on other sites More sharing options...
paulebble Posted October 21, 2023 Author Share Posted October 21, 2023 37 minutes ago, Bianco2564 said: Just thinking about how the valve works, not familiar with them. Is the electrical connection a priming function, turn ignition on or crank it and 12v is sent to the valve to flow fuel? Once the engine starts, the intake vacuum takes over? Can you bypass the valve and just connect the carb straight to a fuel supply and check the engine runs.? Check what the 12v supply does when you switch the ignition on. Check that the valves earth is good. The engine was running before the valve was changed. Now I’ve worked on the valve I hunk the electrical supply is for the level float attached to the valve. This will display the tank level when it gets low. The earth is good on the valve. There is no noise and I can’t feel the valve doing anything when I turn the ignition on. I’ll try to get a good supply to the carb and see what happens? I’m thinking it’s the carb as I’ve just been told it was hard to start before the valve change, but once running it was ok. Quote Link to comment Share on other sites More sharing options...
RideWithStyles Posted October 21, 2023 Share Posted October 21, 2023 You shouldnt feel much at the valve as it just essentially a tap not a pump, simply open and close like a reed valve. So id be looking at the state of the hoses for cracks so look closely while you bend and squeeze, clips that dont grip, gaskets and seals. oh yeah just incase Dont use E10 petrol... Quote Link to comment Share on other sites More sharing options...
paulebble Posted October 21, 2023 Author Share Posted October 21, 2023 3 minutes ago, RideWithStyles said: You shouldnt feel much at the valve as it just essentially a tap not a pump, simply open and close like a reed valve. So id be looking at the state of the hoses for cracks so look closely while you bend and squeeze, clips that dont grip, gaskets and seals. oh yeah just incase Dont use E10 petrol... Hi, I’ll check the hoses and clips and the rubber boot to the carburettor tomorrow thanks. Why not E10 petrol? Quote Link to comment Share on other sites More sharing options...
RideWithStyles Posted October 21, 2023 Share Posted October 21, 2023 Eats rubber and seals, probably why your valve pissed out the first time. Me and my mechanic mate has seen this good to many times especially when they first introduced it on the forecourts and his garage is under one mile from a petrol station. how quickly will be determined by the grade and type of hose, ethanol eats or hardens rubber, even if the bike says it's designed to use it the manual will no doubt have it down as a need to check item on service and deemed consumable after 4 or so years, your bike like ours are no longer spring chickens. Quote Link to comment Share on other sites More sharing options...
paulebble Posted October 21, 2023 Author Share Posted October 21, 2023 12 minutes ago, RideWithStyles said: Eats rubber and seals, probably why your valve pissed out the first time. Me and my mechanic mate has seen this good to many times especially when they first introduced it on the forecourts and his garage is under one mile from a petrol station. how quickly will be determined by the grade and type of hose, ethanol eats or hardens rubber, even if the bike says it's designed to use it the manual will no doubt have it down as a need to check item on service and deemed consumable after 4 or so years, your bike like ours are no longer spring chickens. Aha, well notes thanks. I’ve now ordered new hoses and clips to pick up tomorrow. fingers crossed 1 Quote Link to comment Share on other sites More sharing options...
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