Motorcycle Repair: 1983 V45 fuel system trouble!!!, fuel system trouble, fuel pump relay


Question
I got this bike 1 1/2 years ago it was a blast! Other than figuring out I had to reverse bleed the clutch to get it to work, there were no issues.  Last summer I couldn't ride it cause it wasn't getting fuel.  I cleaned and rebuilt carbs, I had a shop clean and rebuild the carbs, I purchased oem fuel pump, I replaced the fuel cut off relay, and flushed the entire fuel system with gas earlier in the week. When I remove fuel line from carbs and crank it, it doesn't squirt fuel. The fuel pump does click when I turn the key but doesn't run.  Everything has power, even the relay is sending power to pump. I am completely lost with this issue it's driving me crazy!!!! Is there a way to hardware pump without relay? How can I test fuel pump? Could it be in ignition module despite having power to everything.

Answer
Jeff, there have been more than a few of these kinds of questions on these bikes, over the years.

FYI... some history on the models.

http://www.motorcycleproject.com/motorcycle/text/V4hist.html

I believe there were a couple of different designs for the fuel cutoff relay, some triggered by the ignition and some directly from the ignition switch.

http://www.cantonmg.com/stewsplace/ShopManualVF750C.html

http://v4hondabbs.com/index.php sign up and search the archives.

http://www.cantonmg.com/stewsplace/VF750CShopManual/Chapter25-83Addendum/Chapter  Check the wiring diagram sections to follow power through the fuel pump circuit. There is a signal being generated from the spark unit as an input to the fuel pump relay. Spark units are known issues with these bikes and may be contributing to the issue. You should be able to put 12v to the pump wire (white) to verify pump operation. I think some owners have wired around the cutoff relay, so that there is direct power to the pump when the ignition switch is turned ON.

Bill Silver