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Discussion Starter #1 (Edited)
Hi everyone. I'm having an issue on my 07 honda rancher trx420fm. When I turn the key on the fuel pump does not prime. I've replaced the fuel pump and the relay (twice). I bypassed the relay and the pump will run but still not start. Has new battery showing 12v. Spark plug wire shows 12v when key is on, so should be firing. Kill switch seems to be fine. There is very little voltage getting to the fuel pump, 3.8v. Thanks in advance. @Melatv
 

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if that model has a bank angle sensor ?, you might wanna check it.
 

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Discussion Starter #3
I have checked for that. Online shows it to be located beside the output shaft. You can see where one would be but it isn't there.
 

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I have checked for that. Online shows it to be located beside the output shaft. You can see where one would be but it isn't there.
it shows on fich when i looked your model up, it should be on the frame rail right above the rear output shaft ?. is your missing ?, fall off ?. or never there ?, was one there at all before you got your hands on it ?, did this atv ever run lately ?.
 

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Discussion Starter #5
it shows on fich when i looked your model up, it should be on the frame rail right above the rear output shaft ?. is your missing ?, fall off ?. or never there ?, was one there at all before you got your hands on it ?, did this atv ever run lately ?.
it shows on fich when i looked your model up, it should be on the frame rail right above the rear output shaft ?. is your missing ?, fall off ?. or never there ?, was one there at all before you got your hands on it ?, did this atv ever run lately ?.
You can see where it is supposed to be but it isn't there. I bought it used about 8 years ago. I don't know if it was taken off prior to me buying it or if it was never there. It ran fine before I parked it. The next day out of nowhere it would turn over but wouldn't start. I replaced the fuel pump and the relay and nothing. There is very little voltage going to the fuel pump though
 

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Discussion Starter #6
I just realized you said frame rail. The place I'm talking about is the back of the crank case beside the output shaft. I'm at work right now but I'll look again where you mentioned and get back with you. I appreciate it
 

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I just realized you said frame rail. The place I'm talking about is the back of the crank case beside the output shaft. I'm at work right now but I'll look again where you mentioned and get back with you. I appreciate it
correct, it mounts to the underside of the frame rail.
 

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Discussion Starter #8
I finally found it. It is located between the breather box and battery underneath the plastic on the frame, straight above the output shaft. Do you know how I can bypass it or use a jumper long enough to see if that's the issue?
 

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Discussion Starter #9
I put a jumper on it and the relay would click when it made contact but the fuel pump still won't prime or start. Figures lol
149806
 

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is the fuel pump oem from honda ?, or an ebay piece of china junk ?.
 

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Discussion Starter #11
It is an Ebay piece of junk lol. Do you know what the required voltage is to operate the fuel pump? I'm getting 3.9 volts
 

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It is an Ebay piece of junk lol. Do you know what the required voltage is to operate the fuel pump? I'm getting 3.9 volts
you must have 12 volts to operate the pump. please try to get your money back, and buy an oem fuel pump from say, www.partzilla.com .
 

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Discussion Starter #14
you must have 12 volts to operate the pump. please try to get your money back, and buy an oem fuel pump from say, www.partzilla.com .
That makes me wonder if the problem is the voltage instead of the pump. Its showing 3.9 volts at the plug. I ran a straight wire from the battery to the fuel pump and the pump would run but it still wouldn't start
 

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That makes me wonder if the problem is the voltage instead of the pump. Its showing 3.9 volts at the plug. I ran a straight wire from the battery to the fuel pump and the pump would run but it still wouldn't start
check all your fuses, BOTH SIDES OF THE FUSES WITH A 12 VOLT DC TEST LIGHT WITH KEY ON.
 

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i dont know why your only getting low voltage ?, unless the relay has something to do with it ?. but i do know it takes 12 volts to operate pump.
 

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Discussion Starter #17
i dont know why your only getting low voltage ?, unless the relay has something to do with it ?. but i do know it takes 12 volts to operate pump.
I've checked all fuses and even replaced the relay twice thinking I bought a bad one. You can hear the relay click when you turn the key on. I've tried jumping the harness in several places and still nothing. Its not making any sense lol
 

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I've checked all fuses and even replaced the relay twice thinking I bought a bad one. You can hear the relay click when you turn the key on. I've tried jumping the harness in several places and still nothing. Its not making any sense lol
you may want to ask over on www.atvhonda.com, we got some very smart members there, knows more than me on this model for sure !.
 
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