Good starter, Good battery, Good selonid, won't turn over

I went to go run some errands on my 85k100rs.
It started right up. I gave it a min to warm up. backed down my driveway, put it in 1st. pulled away I went 25 feet maybe I stopped at the mail box. That is when it died.
I hit the start button, I hear the fuel pump, but the starter does nothing. So I pull the tank (I just filled it last night) Test the solenoid and 12.39V going to solenoid but not to the starter. I jumped the solenoid and the starter worked. Cool I thought
So I took the starter solenoid out of my k75 put it in my k100, hit the starter. Still nothing.

I also tried to start it by jumping the solenoid. I turned the key on, Kill switch on, hit start buttom and jump selonid at the same time (to run the fuel pump) turned over but wouldn't start.

Any Ideas?

Thanks for any help!

Chuck

There are several circuits involved with the starter.. one goe through the starter itself for the load-shed circuit... and there are the interlock circuits for the starter itself.

It sounds as if your interlock circuits are keeping the starter relay from energizing the starter. There are several: (1) Interlock for neutral (2) Interlock for the clutch. If you are in neutral, the starter should operate even if the clutch isn't pulled in. If you are in gear - the starter should only work if the clutch IS pulled in. There is no sidestand switch like later bikes since the sidestand is self-retracting when the clutch is pulled in.

That's just a general sort of hint as to where to start looking. Check the action of both switches, see if either one enables the starter.

As to why it doesn't start when the starter is engaging - dunno. I'd be checking for spark and injector voltage.

BTW - you HAVE checked ALL the fuses right?

I did check the fuses. all were good, I also changed each fuse. all are good.
I had to leave to go to work, so I won't be able to check till i get home.

Would a bad hall efect sensor cause my problem?

I'm sure you took something from the K75 to swap to the K100 but I am also sure it was not a starter solenoid - since neither bike is equipped with one.

Did you swap the starter relay - the one with the two big wires in the electrics box?

Did you actually pull the starter from the rear of the engine case?

It's a bit tough to diagnose when I don't really know what component was swapped from bike to bike.

Yes it was the starter relay I swaped out of the k75 to put in the k100. Sorry if I called it the wrong name.

No I didn't remove the starter, When I jumpered across the starter "relay" The starter worked fine. when I hit the starter button I get no voltage going to the starter, but I do have power going to the relay.

chuck

chuck_donahue said:

Yes it was the starter relay I swaped out of the k75 to put in the k100. Sorry if I called it the wrong name.

No I didn't remove the starter, When I jumpered across the starter "relay" The starter worked fine. when I hit the starter button I get no voltage going to the starter, but I do have power going to the relay.

chuck

Click to expand...

Which leaves you troubleshooting the protective control circuity for the coil on the starter relay. I'd start at the relay - measure across the coil when the button is pressed and work backwards. Right now, I'll predict you have no voltage at the starter relay coil. When you find voltage (working backwards from the coil) - you'll find what the problem is.

BTW - you do have a manual with a circuit diagram right?

I have 2 manuals, a clymer, and a haynes. Looks like a fun filled morning for me! I had hoped someone would have said .... I had the same thing it was .... but no such luck.

But one thing I didn't think mutch about it till tonight.
2 weeks ago I went to town on the k100, when I left to go home it wouldnt start. I had planed to get gas 1st thing 170 miles on that tank so I just figured I had run out. no problem 2 blocks away is a gas station. almost downhill. Well I get there, open my gas cap and find I have alteast a gallon in there. so I am not out of fuel. We pushed it across the street. My son was going to go home and get my truck and some tools. Well by the time he got backto his bike and got it started, my bike started. I rode straight home (I didn't get any gas). I have put almost 300 miles since then, problem free. So I bet It has something to do with that.


And my bike always starts very easy. hit the start button 2 sec. that primes the fuel rail, hit start again .... instantly it is running.

thanks

I will let you know what I find. I may have to wait a day and put my k75 back together so I have something to ride.
Took that apart to put a K100rs fairing on it.

FI does not go through starter interlock.

A tell on this problem : Is the head light on when Ign sw is on and starter button
is not pressed? If not then the starter cumutator and brushes are dirty with oil
vapor residue.

The starter could still run if the relay is bypassed.

You can sometimes get out of this temporally by putting the bike in 4th or 5th gear and rolling it backward with the clutch engaged(not pulled) untill the head light comes on.

This rotates the starter backward rapidly and most times moves the crud around untill the brushes make contact.

Soon you will have to pull and clean the starter.

Hope this helps.

The Lonerider

The headlight is on, It dosn't go off when I hit the starter, like it always did and should.

Fixed

Ignition control unit was bad. Pluged in a new one (well it is far from new, I bought it for $35.00 on ebay 2 years ago). I just looked up a new one 1,198.86

Thanks to everyone for your ideas and help.

I'm glad you got it figure out Chuck. On the road again.


Roc