1998 Kawasaki Vulcan 88 1500A. This is NOT a classic. This is NOT a Nomad. Dual carbureted bike. For the last year, I have been bringing this bike back to road worthiness. I tried a gravity feed on this bike and it simply didnt like it. So, I had to put the fuel pump back in it. The pump that was originally in it was bad. So from FuelPump World, I bought a pump. Middle of the road cost so I figured it would be alright. It gave me a grand total of 20 miles before the pump failed. Since this company stated that they had a 1 year no questions asked replacement warranty, I ordered another one. This one....lasted a grand total of 10 miles. So, I bit the bullet and bought a Kawasaki pump. This pump lasted a grand total of 2 miles. With these pumps, the bike runs poorly. Feels like its running on one cylinder. I spent the winter doing a vinegar bath on the fuel tank, took apart the carbs and reconditioned them. Cleaned all the rust and placed 2 fuel filters in the system to combat any residual rust. One before the pump, one before the carbs. Bike has new CV slide diaphragms and they are installed properly and rise when air is blown through the port on a bench test. I severely doubt the problem is in the carburetors. They been off this bike so many times and came off after the bike stalled this time around. Zero rust, zero problems within the carbs. Everything is as it was when I installed the bike

Now, I suspect I have an electrical issue with this bike causing the problems. Looking at the schematic, I see no fuel pump relay. Instead it looks like the pump receives pulse power from an ignition coil. This would make sense as to why the bike is dropping out a cylinder and burning up fuel pumps. However, it seems the wiring schematic is incomplete. I have 2 wires that seem to go to other components that arent shown where they go. When the pumps fail, testing of the electrical system shows no problems. Pump has power and ground. They are steady voltages. Battery is AMG and new 4 months ago. Anyone have experience in dealing with this and what they did to remedy their problem? Short of replacing every electrical component or placing some aftermarket fuel pump system, I would like to get proper diagnosis to repair what is killing these pumps.

 

Well, based on the number of threads here with no replies, I am guessing this forum is pretty much dead.

 

Pretty much.

It also means no one has any meaningful input to offer and that includes me. However, one phrase caught my layman's eye.

"Instead it looks like the pump receives pulse power from an ignition coil."

WTF????? Ignition coil???????

Shouldn't a fuel pump ONLY receive constant 12 volts from a relay when the ignition key is on and a pressure regulator does the rest of the job?

 

Not this particular bike. The wiring schematic shows a wire from the ignition coil to the fuel pump. This fuel pump has 4 wires going to it. This fuel pump is not a turbine fuel pump. This fuel pump is a solenoid lift style fuel pump.

 

One of my biggest pet peeves of internet help is forums like this that dont give an answer to a problem that was remedied. I see no reason to start now. The bike is fixed. Runs great. What was it? No one but me will know. Thanks for nothing.

 

You are correct the black wire goes to fuel pump and to the 1 coil for a ground pulse. I'm guessing the more pulse the more that black wire tells the pump to pump or switch from low to high.. so my 1500e6 has a diode rectifier for that goes to the fuel pump.. possibly your bike has as well if it's a e model carbed.. it changes from ac to DC and no back draw
. The black.and red wire.going to pump..