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Fuel pump question

Posted: Mon May 30, 2011 1:11 am
by mxryder21
I'm running a yzf750 tank on my fzr600 hybrid. When I turn the ignition on, I do not hear the fuel pump at all. Is that normal? When I tried to start the bike it turned over and I could see fuel moving through the fuel filter but the bike wouldn't fire. After like 5 min. (total) of trying to crank the bike over I gave up. I have the blue wire from the tank connected to the blue/black wire on the fzr harness and the black to black. The green wire I know is for the low light. I guess the pump could be bad but is there a way to check it?

Re: Fuel pump quesiton

Posted: Mon May 30, 2011 3:54 am
by ronny86
from my short time of owning a fzr i believe if the carbs are full of petrol then u wont here the fuel pump, when my fuel pump did the same i unclipped it from the carbs and tried to start bike to see if the fuel was getting through... mine turned out to be a bad earth wire...

heres a quote from when my fuel pump went
DonTZ125 wrote:*wince* Check your Ignition fuse, check the wires and connectors at the pump, TCI, and main relay assembly (left side rear, behind the seat fairing).

Re: Fuel pump quesiton

Posted: Mon May 30, 2011 7:33 am
by cad600
Pull the fuel line from the carbs and have it pour into a fuel container. Turn the key ad flip the switch. If fuel is pumped through, then it should be working. If not, then check the electrics first before discarding the pump.

Being an internal pump, you don't notice the sound as much as the FZR600 pump. As stated, if the carbs are full, the pump won't push any more fuel either. I routinely don't hear mine prime the carbs.

Re: Fuel pump quesiton

Posted: Mon May 30, 2011 8:54 am
by mxryder21
Thanks for the replies fellas, I guess I should have been more clear though. My bike has been in pieces for the last 2 years and this is the first time I have tried to fire it since putting it all back together. The fuel line and filter was empty when I first tried to crank it over, so once I saw the filter start to fill with gasoline I knew that was a good sign even though I never heard the fuel pump prime. Having said that is there anything specifically I should do or should have done already to facilitate starting a bike that hasn't been started in over 2 years? The starter sounds really strong and the motor cranks over it but didn't fire last night.

Re: Fuel pump quesiton

Posted: Mon May 30, 2011 4:37 pm
by mxryder21
UPDATE:

I connected the bike to the battery tender, turned on the ignition "on" and had the red switch set to "run". I then tried to get a reading on the "tank side" of the fuel pump electrical connector and didn't get a reading so I disconnected the plug and tested the "harness side" of the connector and also got no reading. Am I doing something wrong? I checked the fuse block and there are none blown. I haven't checked the main fuse due to the difficulty gaining access to it but I don't think the bike would turn over if that were the problem, right? HELP!!!

EDIT: Okay, when turning on the ignition, I noticed a 1-time click on and the off. I traced it to the main relay. So, I turn the ignition off, hooked up the voltmeter to the fuel pump plug on the harness side and then turned on the ignition. It read 12v for about 5 seconds and then I heard the click and it dropped to 0. WTF? Is that normal? I'm going to try and start it with the volt meter connected to see what the plug reads.

EDIT 2: Well, looks like I have a smoked fuel pump. I hardwired it straight to the battery and nothing happened. Switched the wires and still nothing :swear :swear :swear :swear :swear :swear :swear :swear :swear :swear :swear :swear :swear :swear :swear :swear :swear :swear :swear :swear :swear :swear :swear

So, is there a way to use the yzf750 fuel tap with an external fuel pump and bypass the in-tank pump? I have the stock fzr fuel pump around here somewhere, OR should I look for another yzf600/yzf750 in-tank pump?

Re: Fuel pump question

Posted: Mon May 30, 2011 7:01 pm
by DonTZ125
Can't help you with the pump itself, but that click from the main relay assembly is the pump relay; ON for 5sec then off is perfectly normal - it means both the relay assembly and TCI are working.

I'm not sure how robust the YZF pump is; it may be possible to simply smash it apart and use the head as your outlet. Connect the FZR petcock and fuel pump as though it was stock (no reserve, obviously). If you gut it carefully enough, you might get free-flow through the pump housing and a reading from the low-level sensor.

Re: Fuel pump question

Posted: Mon May 30, 2011 7:40 pm
by sweekster
Good advice so far. I would pull the pump out and clean all the fuel lines and the inside of the tank. Easier to do with the 750 tank. Be a good time to test the pump itself. If it works then you have blockage and the carbs aren't priming fully- which goes back to what I suggested about a good clean. My 1k sat for almost 4 years until I came along and took a solid hour for it fire up. Double and triple checking can be a pain but worth it in the end.

Re: Fuel pump question

Posted: Tue May 31, 2011 3:41 am
by mxryder21
Well, the previous owner of the tank had apparently done something funky with the wiring and to make a somewhat long story short, the low level indicator and power wire for the pump got switched. So after many many many many attempts at cranking this thing over (while it wasn't getting any fuel) I FINALLY got the bike running. I let it run for about 5-7 minutes before shutting her down. MAN! she sounded like sh!t though... straight header, but Im getting the midpipe made tomorrow. I had to run K&N pods so the bike idled fine but when I tried to give it throttle it choked on anything over 2,200rpm, however, I have a brand new stage 3 jet kit to install so that and a few other things are still on the to-do list. Thanks for all the replies; it's much appreciated!