‘85 K100 Starting issue (actually a non starting issue)

I have a problem with my 85 K100.

It was running great in 2020 and I changed all the fluids.

Covid hit and it got parked.

It sat for 2 years on the centre stand attached to a trickle charger.

The clock was still working so it kept power but it will not turn over. Not even a click.

I tried boosting but that did not help.

When I turn the key to start there is a whirring sound and the tach registers RPMs.

Fuses appear to be good.

Ideas?

I have to throw out the “how old is the battery question”. Could very well have enough “surface charge” to run the clock…..and not start.
OM

The whirring sound, if soft and "for a couple of seconds", is the priming of the fuel pump; if it's LOUD or continuous, I'd suspect the starter... but not engaging to the flywheel, meaning a dirty sprag (sp?).

Tach - is it jumping around wildly, or showing that the bike is attempting to turn over? If it's jumping around, that would indicate an ignition problem.

How many volts between the positive terminal of the battery and the ground bolt on the side of the the transmission just above the shift lever?

Does the voltage change when you turn the key on? When you hit the start button?

How much voltage between the hole in the back of top fuse and the ground bolt with key on?

How much voltage at starter when you hit the starter?



Before trying to start the bike, I would strongly recommend insuring that the fuel has not broken down and attacked the fuel pump rubber damper. Trying to start a bike with a deteriorated damper can suck the contaminants into the pump and injectors and cause hundreds of dollars in damage.

A word of advice on starting a recalcitrant Kbike. If you get a low voltage start, it's entirely possible for the starter relay to weld itself shut and the bike will continue to crank itself, even after you turn it off and take the key out. That can be very, very exciting, let me assure you.

For this issue, I'd start with checking to make sure the starter relay in the relay box under the tank is properly seated, the ground cable is making good contact from the battery, terminals are clean and that the battery has a full 13.8 volts before I hit the Go button. You really don't want to try a low voltage start.

If that still results in a no crank scenario, then I'd check at the starter to ensure you're getting voltage there as well as checking back at the relay to ensure there's voltage being supplied there, basically checking voltage at each of the connections along the way.

It will likely be somewhere in that mix.

If it cranks and doesn't fire, then it might be time to look at a fuel pump that has turned its innards into a pile of black goo.

My 2 cents.

I read your post correctly and it's not cranking, right? And since I've heard people use "cranking" in ways I didn't expect, the motor is not turning over at all, right?

You need a battery. Maybe more, but you need a good battery before you can get any farther.

Problem solved

Thanks for the help.

Special K is back on the road.

DWEBB49 said:

Thanks for the help.

Special K is back on the road.

Click to expand...

What was it?
OM

Battery

DWEBB49 said:

Battery

Click to expand...

Always check the simplest things first.