K75 just died... HELP!!

[Beembish]

OK - here is the long and short of it. Bought the 87 K75S last year for my 16yo son. 16,000 miles. The paint was real faded... marakesh Red.

 

We worked on it stripping down the fairing parts all except the tank. Just got it back from the paint shop 3 1/2 weeks ago. Beautiful!!! This bike has always started real good and even after sitting all winter it fired up. My son rode it all around the AM Legion parking lot for abot 20 minutes Sun morning. Ran perfect. Got the bike all title and registered in his name today and he's ready to take his first ride today at 6pm. He turned 17 on Saturday.

 

Now the problem. We started the bike up and noticed low fuel light. Shut the bike off and got the gas can. Opened up the tank lid and noticed about a 1/3 cup water in the filler and before we could absorb the water with a cloth it leaked down into the tank. I immediately put some isoprophyl alcohol in the tank along with about 1 1/2 gallons of gas. We started up the bike and half-way down the drive it quit.

 

I have checked the spark, the fuses and even disconnected and checked the gas hoses. There did not seem to get much gas out of either. I tried to turn the bike over to see see if it would pump gas.

 

A couple of questions:

 

Is there a way to check to see if the fuel pump went bad?

Do you think it is just the water that messed it all up?

[Dennis Andress]

Sounds like you know what you're doing, hope your kid appreciates it.

 

It wouldn't be a bad idea to drain the tank and get some fresh gas. I don't know what affect isoprophyl alcohol would have, but the bike will run better without it. Those fuel pumps don't like water. They quickly corrode and freeze. But, it doesn't 1/3 cup doesn't sound like a lot. Maybe the fuel filter is clogged.

 

The fuel pump should run for a few seconds when the key is turned on, if the sidestand is up. The #1 throttle body should have a vacuum line connecting it to the fuel pressure regulator, sucking on the line will open the regulator and release residue pressure on the fuel injectors.

[Paul Mihalka]

One more thing on K75 bikes with low mileage: they may have been stored with old gas for a long time. With old gas the rubber boot that holds the fuel pump deteriorates, breaks up, and pieces get sucked into the fuel pump. End of fuel pump.

[Beembish]

THanks... made an appt for Sat morn to have a fuel pump installed at Heids in the Adirondacks. I checked the fuses twice and there is no pump sound when I turn on the key. I have confidence they will have me back on the road Or should I say back on my truck for the ride home on Sat.

[kobukan]

THanks... made an appt for Sat morn to have a fuel pump installed at Heids in the Adirondacks. I checked the fuses twice and there is no pump sound when I turn on the key.

The fuel pump will not run when you turn the key on. It will run for a few seconds only after you hit the starter button.

 

It should be easy to hear the pump. If the pump doesn't run when the starter button is hit, check electrical connections to make sure they're fully seated. The power to the fuel pump also passes through the fuel level sending unit inside the tank and they have been known to go bad (easily replaced for about $100) causing the fuel pump to not have power. If all connections look OK I'd test to confirm you're getting power to the wire at the fuel pump when the starter button is pressed. If you have power there and the pump doesn't run then you've isolated the problem to the pump itself - replace. If no power at the wire at the pump - pump is not the problem - follow wiring back until you find out where the disconnect is.

 

Personally, at this point I'd just drain/clean the tank and check power to the fuel pump at the same time. Then proceed from there.

[SKYGZR]

Install new filter