K75 starting problem

[Neil Carrick]

I am new to the forum as I am in need of some advice. I ride a 1988 K75C, currently has about 140,000 miles and ran great until I parked it a couple of years ago. Presently putting in a new fuel pump kit from Euro MotoElectrics and a new Shorai battery. The reason I parked it in the first place was what I term an "electrical problem". At times it would start up as it should then at other times it just would not do so. I replaced the starter button unit, had the alternator checked etc. etc. took it to the local BMW shop in Vegas which incidentally is terrible but they could not find any issue and told me it was fine until I rode it home and became stranded at a local gas station. So, can anyone offer any insight as to what my issue could be???? In advance thanks for taking the time to read my post and ponder my issue..

[frankenduck]

Does it just not start or does it quit while running to?

If it cuts out while riding too then the ignition switch or fuel tank connector are usual suspects.

If it just won't start then you can remove/clean the start/kill switch.
Link: http://www.kbikeparts.com/classickbikes.com/ckb.tech/0.ckb.tech.files/startkillrehab/startkillrehab.htm

Other things to try:

* Detach and reseat the L-Jetronic connector under the seat.

* Check battery connections and ground on left side of transmission.

[The Mighty Gryphon]

Taking the Duck's reply a bit further, does the starter run but the engine doesn't fire or does the starter not run when the start button is pushed?

Does the instrument cluster light up when you turn on the ignition switch, but the starter doesn't turn? 

If the engine quits while you are riding, does turning the key off and back on make the engine run?

I have had problems with the key switch on two of my bikes.  I now service that switch on my bikes when I get them as a preventative action.  Problems with it are not uncommon and several people have posted articles on servicing it.

http://www.eilenberger.net/K75S/IgnitionSwitch/

[frankenduck]

Here's another ignition switch cleaning by Jim Davis of Eastern Beaver:

http://www.k100.biz/Electr/_NT/NT_Ignition_Sw.pdf

[The Mighty Gryphon]

Regardless of what instructions you use, it is a good idea to make an "operating table" that will catch any small parts that will make a bid for freedom.  If your garage is like mine, once they hit the floor they're gone forever.

[Neil Carrick]

Hello,

The issue can happen when I have turned the bike off, never whilst actually running. I will turn the key on and absolutely nothing will happen, does not show 0-neutral in the LCD gear selector screen as I always place in neutral upon stopping etc. etc., no fuel pump noise, no starter run, everything seems to be dead.

The start/kill switch housing/unit is itself pretty new so I don't think that can be the issue.

I have very clean battery connections and checked those numerous times through to the ground etc.

I have never changed and or serviced the bikes Key Switch, (Ignition switch)--I like that idea and frankly never thought of it. Blimey...

I will also locate the L-Jetronic connector under the seat and detach and reseat it. (Not sure what that is or were it is but I shall figure that out)..

Thanks to you all for all your input and hopefully this will help.

[Laitch]

I have never changed and or serviced the bikes Key Switch, (Ignition switch)--I like that idea and frankly never thought of it.

I will also locate the L-Jetronic connector under the seat and detach and reseat it. (Not sure what that is or were it is but I shall figure that out)..

Clean the ignition switch. You don't need to figure out the L-Jetronic; you need to click on the L Jetronic.pdf link in this post then read about the system. It'll save you some time.  The 1994 K75 Rider's Handbook (Manual) in the Service Manual section of this site will also help you locate your ride's equipment—like the L-Jetronic, but some of the elements in the handbook's Specification chapter won't apply to your '88.

[Neil Carrick]

Cool, I will work on the ignition switch.. Thanks..

[Neil Carrick]

Hello,

So I have installed a new fuel pump, checked the ignition switch out etc. No Joy, will NOT start.. Took it to a mechanic who states it's only getting power to one plug, not sure what that means. At present he has had the bike and worked on it for about a month and cannot figure out the issue. My neutral light switch will not work. can that be the cause of the issue?? (Obviously if that doesn't work I would pull in the clutch prior to starting).

Sadly I am getting ready to move to NC and if I cannot get the bike to run I will probably leave it behind. I just don't see the need to spend upwards of $800.00 to ship a bike if it doesn't work so my time is running out on this..

Thanks for any input on the matter.

Respectfully, Neil Carrick

[frankenduck]

It's possible that the clutch switch has failed.

[The Mighty Gryphon]

Does the starter turn the engine and it won't fire?  Or does the starter not turn the engine?

The neutral switch only prevents the starter from turning.  If the engine turns, the neutral switch won't stop it from firing. 

Are the plug wires on the correct spark plugs?  You would not be the first person to get the #2 and #3 plug wires crossed.  The longer wire for #3 fools many a newcomer to the Brick engine.  If you have the original wires with the metal caps, you will see that they are numbered for the cylinder they go to.

Can you hear the fuel pump run when you push the start button briefly? 

If you can crank the engine over with the starter, after 5 seconds of cranking are the spark plugs wet with fuel?

[daveson]

Yeah could be the clutch switch or gear switch. What lights are on, and fuses with power, with ignition on?  And with the start button pressed. A wild guess about spark only on one cylinder, clean the hall sensors plug.

It's probably just some simple problems, too minor to consider selling, I'll guess.

[Neil Carrick]

Hello,

Thanks for all the input it is greatly appreciated. I shall discuss some of your points with the mechanic currently working on the machine.

As to the spark plug wires, when I removed them earlier and placed new plugs I labeled them so as to not place them incorrectly.

It might only be a simple issue but it has left me stranded a couple of times at gas stations as the bike wouldn't start after filling up, so sadly minor or not if I cannot get this fixed it will be given away, sold, (not a fan of being stranded, LOL kind of ruins the ride)....

[frankenduck]

Does the starter turn the engine and it won't fire?  Or does the starter not turn the engine?

Or starter not turn at all?

This question needs to be answered first to start troubleshooting.

[Neil Carrick]

The mechanic states that the bike will turn over but when he turns it on you cannot hear the new fuel pump "Prime". No power getting to the pump.

[frankenduck]

Not uncommon for the fuel tank connector to become flaky.  Tell him to test for 12V on the green/white wire of the fuel tank connector from the main wiring harness when turning the motor with the starter. 

K75s don't prime the fuel system.

The green/white wire for fuel pump power only gets power when the engine is turning which is why you have to be spinning the motor with the starter to test for fuel pump power.

[The Mighty Gryphon]

As I suggested the other day in reply #10, press the start button for a second and release. 

Two things should happen.  First, the starter should spin the engine over a couple times.  Second, when you release it, you should hear the fuel pump whine for a half second.

[daveson]

I spose I should have added using electrical cleaner on the plug the hall sensors goes to, the computer under the tank, especially if the rubber boot cover isn't seated correctly. And a lot of other connections too.

[alexg]

Is this a spark or a fuel issue? Spray some carb cleaner down the intake tubes and see if it fires. It seems to me that until you know whether is a spark or fuel issue, you are going blind.

[frankenduck]

Is this a spark or a fuel issue? Spray some carb cleaner down the intake tubes and see if it fires. It seems to me that until you know whether is a spark or fuel issue, you are going blind.

No need to remove any thing other than the airbox snorkel. You can just spray starting fluid into the right side of the airbox.  If you're getting spark then the bike will run for a few seconds on starting fluid.

[Neil Carrick]

Hello,

As before, thanks for the advice given. Upon follow up with the mechanic today he told me that the bike will "crank but not provide any power to the fuel pump" He stated he would have his "electrical guy" look further.

Respectfully, Neil,

[The Mighty Gryphon]

  A month and just finding out the fuel pump isn't running?   I really hope your mechanic's hourly rate isn't more than $10/hour.

[daveson]

Me thinks so too, at least he's got the cranking problem sorted.

If there there is only power on one plug, if it's plug three, I'd be checking the earth wires from three, to one and two.

[Past-my-Prime]

There is a plug under the fuel tank. It has four pins. Therefore it's called the "4-pin". It is a common source of loss of power to the fuel pump. Take it apart, clean it, spray it with contact cleaner, put back together, and see if the fuel pump runs then.