Author Topic: Awakening 1987 K100RS from 10 year slumber.  (Read 5448 times)

Offline SpecialK

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Re: Awakening 1987 K100RS from 10 year slumber.
« Reply #75 on: July 06, 2019, 02:54:31 PM »
Two gallons is enough to start and run it. Check a spark plug after cranking. Is it wet or dry? If electrical connections are ok, you'll hear the pump run for a second or two when you release the starter button. If you don't hear it, reconnect the four-pin connector and verify that the fuel pump's fuse (#6 counting from the top) is ok. Verify the fuel filter is oriented in the correct direction. Verify that all hose connections are tight. Verify that the outside fuel hose to the rail is connected to the rearward tank port and the return hose is connected to the forward port. Verify that the plug wires are connected to the correct coils.

All good. I can hear the fuel pump and I double checked all the connections. As soon as I go get a turkey baster or syringe I am going to try 10cc of oil in each cylinder head for compression and check back later.
  • Wappingers Falls, New York
  • 1987 K100RS
"The first to present his case seems right, till another comes forward and questions him". Proverbs 18:17

Offline SpecialK

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Re: Awakening 1987 K100RS from 10 year slumber.
« Reply #76 on: July 07, 2019, 03:03:51 PM »
Ok, just went out and squirted 7-10ml of motor oil into each cylinder head hoping it would improve compression and start, but nothing. Tried choke then no choke.

-Wires 1,2,3,4, are all correct to each cylinder.
-Gap set at .7mm
-fuel filter aligned correctly with "IN" towards the fuel pump meaning fuel coming from the pump is going to the "IN" side of the filter.
-All fuel hoses hooked up tight.
-bike in neutral with green light on.
-fuel level at 1/4 tank.

The plugs are the older Bosch X5DC so I am going to try the new NGK D7EA. Will need to get the terminal nuts.
  • Wappingers Falls, New York
  • 1987 K100RS
"The first to present his case seems right, till another comes forward and questions him". Proverbs 18:17

Offline Martin

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Re: Awakening 1987 K100RS from 10 year slumber.
« Reply #77 on: July 07, 2019, 03:12:09 PM »
After failing to start, are the plugs wet or dry? Terminal nuts can sometimes be sourced from your local mower repair shop.
Regards Martin.
  • North Lakes Queensland Australia
  • 1992 K75s Hybrid, Lefaux, Vespa V twin.

Offline SpecialK

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Re: Awakening 1987 K100RS from 10 year slumber.
« Reply #78 on: July 07, 2019, 03:27:00 PM »
After failing to start, are the plugs wet or dry? Terminal nuts can sometimes be sourced from your local mower repair shop.
Regards Martin.

Thanks for the reply Martin. Plugs are wet and oily looking and were that way when I first took them out.


* IMG_0001.JPG (57.57 kB . 768x576 - viewed 103 times)
  • Wappingers Falls, New York
  • 1987 K100RS
"The first to present his case seems right, till another comes forward and questions him". Proverbs 18:17

Offline Sheff928

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Re: Awakening 1987 K100RS from 10 year slumber.
« Reply #79 on: July 07, 2019, 04:01:31 PM »
That's the same image that you posted on page 2...
Did you check for a spark when you turned the engine over?
  • UK
  • K1100RS 1993

Offline SpecialK

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Re: Awakening 1987 K100RS from 10 year slumber.
« Reply #80 on: July 07, 2019, 05:43:24 PM »
That's the same image that you posted on page 2...
Did you check for a spark when you turned the engine over?

I did not do that yet. I have not worked on a K100 before so what is the procedure? I know on other bikes I have taken the plug out of the socket, put the cap back on and held the threads to the chassis while pressing the start button. Then you can see the spark across the gap.
Is this what you are referring to? Do you check all 4 this way?

Thanks for the input!
  • Wappingers Falls, New York
  • 1987 K100RS
"The first to present his case seems right, till another comes forward and questions him". Proverbs 18:17

Offline Martin

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Re: Awakening 1987 K100RS from 10 year slumber.
« Reply #81 on: July 07, 2019, 06:13:17 PM »
You can't just leave the wires hanging, all leads must be earthed while checking for spark. Failure to do so can result in damage to the computer. The best way to do it, is to do one plug at a time and earth the plug being tested. I made a spark plug test harness that allows me to earth up to four spark plug leads at a time. It consists of four heavy wires terminated at one end to a heavy alligator clip. The other ends are soldered individually onto a 4mm bolt with the head cut off, this allows me to use the terminal nuts for Bosch type plugs or remove the nuts for NGK type. I'll dig it out and post a picture.
Regards Martin.
  • North Lakes Queensland Australia
  • 1992 K75s Hybrid, Lefaux, Vespa V twin.

Offline SpecialK

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Re: Awakening 1987 K100RS from 10 year slumber.
« Reply #82 on: July 07, 2019, 06:41:51 PM »
The best way to do it, is to do one plug at a time and earth the plug being tested.
Regards Martin.

I will try this method, one at a time, while leaving the others in. The procedure is also described in Chapter 6 (11) "Ignition Fault Finding" in the Haines Manual.
  • Wappingers Falls, New York
  • 1987 K100RS
"The first to present his case seems right, till another comes forward and questions him". Proverbs 18:17

Offline Martin

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Re: Awakening 1987 K100RS from 10 year slumber.
« Reply #83 on: July 07, 2019, 08:24:58 PM »
Pictures of four lead earth harness and commercial lead tester. The harness can be used for doing compression testing and checking spark plugs.
Regards Martin.
  • North Lakes Queensland Australia
  • 1992 K75s Hybrid, Lefaux, Vespa V twin.

Offline The Mighty Gryphon

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Re: Awakening 1987 K100RS from 10 year slumber.
« Reply #84 on: July 08, 2019, 12:22:22 PM »
There is a good chance that you flooded the engine when it didn't start right away.  Continued cranking only adds to the excess fuel in the cylinders. 

Following your check for spark, you might want to unplug the infamous four pin tank connector and crank the engine for about 10 seconds with the spark plugs installed to blow out any excess fuel.  With any luck, it might just fire a couple times for you as the amount of fuel left in the cylinders is able to support combustion.

Then plug the tank back in and try starting with the throttle closed and no choke. 

That you don't get a single fire from any cylinder makes me think it's not the coils as it's unlikely to have both coils fail at the same time.  If there is no spark at all, the problem is probably in the ignition control unit or the wiring for the coils(most likely the ground).
  • In my garage in Marilla, NY
  • '94 K75RT Mystic Red, '91K100RS White/Blue, '89 K100RS Special edition White/Blue
Current:
'94 K75RT "Ilsa, She Wolf of the SS"
'91 K100RS "Moby Brick Too
'89 K100RS SE

Offline SpecialK

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Re: Awakening 1987 K100RS from 10 year slumber.
« Reply #85 on: July 08, 2019, 01:48:11 PM »
I am going to try a couple of things when I get home today the first being checking for spark on each plug.

Trying the simplest things first and using process of elimination seems the most logical way to go about it so the plugs spark and the suggestion by Gryphon to run the starter with the fuel pump unplugged would be a good place to start.

Cleaning electrical contacts or other electrical issues would be farther down the list and am hoping doesn't get to that. Hope it isn't something even more complex and costly like a fried injector module.

I am wondering if some of the 10 year old fuel could still be in the lines or the fuel rail? What about the injectors? Could the injectors be clogged from sitting so long?
  • Wappingers Falls, New York
  • 1987 K100RS
"The first to present his case seems right, till another comes forward and questions him". Proverbs 18:17

Offline Martin

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Re: Awakening 1987 K100RS from 10 year slumber.
« Reply #86 on: July 08, 2019, 01:59:26 PM »
Removing fuse number six marked Krafftstoppe will also stop the pump from injecting fuel. A cold Brick should start by just setting the fast idle to the first click. Cranking on the throttle is not required or recommended as this will lead to flooding. The lead tester cost me $10.00 Au and was a worthwhile investment as it can be used to check firing without removing the plugs. It had to be modified to use on NGK plugs.
Regards Martin.
  • North Lakes Queensland Australia
  • 1992 K75s Hybrid, Lefaux, Vespa V twin.

Offline SpecialK

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Re: Awakening 1987 K100RS from 10 year slumber.
« Reply #87 on: July 08, 2019, 03:02:21 PM »
The lead tester cost me $10.00 Au and was a worthwhile investment as it can be used to check firing without removing the plugs. It had to be modified to use on NGK plugs.
Regards Martin.

Thanks Martin. The lead tester does sound like a worthwhile investment and can be used for the car also. I may not have to modify it for the NGK plugs because I was able to get the terminal nuts that fit into the BMW wire leads. Is this what you were referring to when you mentioned modification, because the NGK normally have a threaded tip?
  • Wappingers Falls, New York
  • 1987 K100RS
"The first to present his case seems right, till another comes forward and questions him". Proverbs 18:17

Offline Martin

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Re: Awakening 1987 K100RS from 10 year slumber.
« Reply #88 on: July 08, 2019, 03:18:47 PM »
The tester comes with a built in terminal nut. I can't quite remember whether I had to drill and tap the built in nut to accept a 4mm bolt with the head cut off, or it was already tapped.
Regards Martin.
  • North Lakes Queensland Australia
  • 1992 K75s Hybrid, Lefaux, Vespa V twin.

Offline SpecialK

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Re: Awakening 1987 K100RS from 10 year slumber.
« Reply #89 on: July 08, 2019, 11:02:40 PM »
I bought the lead tester today, the kind that shows the spark jumping across a gap just like a real plug, not the one that lights up. Set the gap on the tester to 0.7mm and tested all 4 leads and there was spark. Not sure how strong the spark was as it was daytime outside but I did see spark.

Tried the trick Johnny mentioned in "No Start" #1 rolling the bike in 3rd gear in reverse and popping the clutch for 3x. Also tried jumping it in 3rd gear rolling forward with no luck.

One strange thing I don't know if it has effect on the bike starting is it looks like someone messed with the ignition switch (see photo). The ignition is OFF in the ON position and has to be turned to the 3 O'clock position for ON. Looks like it was put in wrong but it doesn't seem to affect the ignition being turned on.

Everything is OFF

* IMG_0002.JPG (36.94 kB . 768x576 - viewed 100 times)

Everything is ON in start position

* IMG_0003.JPG (39.06 kB . 768x576 - viewed 98 times)
  • Wappingers Falls, New York
  • 1987 K100RS
"The first to present his case seems right, till another comes forward and questions him". Proverbs 18:17

Offline Sheff928

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Re: Awakening 1987 K100RS from 10 year slumber.
« Reply #90 on: July 09, 2019, 05:23:33 AM »
That's good news :-)

Have you pulled the injectors and checked for fuel delivery?
One thing you might do quite easily is check if the plugs smell of petrol. That's the proper term I believe...  :-D
If not then you have a fuel delivery problem and it could be that your injectors and/or fuel rail are blocked. Can you remove the injectors from the head whilst leaving them connected to the rail and crank the bike to see if petrol is sprayed?

Kindest regards,

Kevin
  • UK
  • K1100RS 1993

Offline natalena

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Re: Awakening 1987 K100RS from 10 year slumber.
« Reply #91 on: July 09, 2019, 07:14:32 AM »
One strange thing I don't know if it has effect on the bike starting is it looks like someone messed with the ignition switch (see photo). The ignition is OFF in the ON position and has to be turned to the 3 O'clock position for ON. Looks like it was put in wrong but it doesn't seem to affect the ignition being turned on.

Seems the key in vertical orientation is normal, at least on mine it is.

Getting accustomed to the flat part of the key (BMW emblem) being pointed towards the label is an easy fix, and the key folds flat against the dash when in "on." I wouldn't worry about it. Cheers
  • East of Joshua Tree
  • 1987 K75s #0919
On Holy Quest seeking Techron equivalent for splines.

Offline SpecialK

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Re: Awakening 1987 K100RS from 10 year slumber.
« Reply #92 on: July 09, 2019, 08:25:18 AM »
That's good news :-)

Have you pulled the injectors and checked for fuel delivery?
One thing you might do quite easily is check if the plugs smell of petrol. That's the proper term I believe...  :-D
If not then you have a fuel delivery problem and it could be that your injectors and/or fuel rail are blocked. Can you remove the injectors from the head whilst leaving them connected to the rail and crank the bike to see if petrol is sprayed?

Kindest regards,

Kevin

I mentioned this a few posts back. It was one of my first concerns/questions since I bought the bike used and it had been sitting for 10+ years with petrol in the tank and a rotten fuel pump I had to replace. I have not noticed a petrol smell on the plugs or in the cylinder heads so I am suspect that maybe fuel delivery is the problem.
Thanks Kevin.
  • Wappingers Falls, New York
  • 1987 K100RS
"The first to present his case seems right, till another comes forward and questions him". Proverbs 18:17

Offline The Mighty Gryphon

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Re: Awakening 1987 K100RS from 10 year slumber.
« Reply #93 on: July 09, 2019, 09:51:45 AM »
First, to answer your question about 10 year old fuel in the injectors plugging them.  Do bears use Charmin?  It would be a very good thing to have the injectors cleaned.  They could either be stuck closed or open.  In any event cleaning them will get the bike running properly faster than trying to run the bike with fuel system cleaner in the fuel.

The key position is correct.  The folding key has a triangle pointer molded in the plastic under the BMW roundel.  when the key is folded it will point at the correct position on the label.
  • In my garage in Marilla, NY
  • '94 K75RT Mystic Red, '91K100RS White/Blue, '89 K100RS Special edition White/Blue
Current:
'94 K75RT "Ilsa, She Wolf of the SS"
'91 K100RS "Moby Brick Too
'89 K100RS SE

Offline SpecialK

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Re: Awakening 1987 K100RS from 10 year slumber.
« Reply #94 on: July 09, 2019, 12:47:09 PM »
First, to answer your question about 10 year old fuel in the injectors plugging them.  Do bears use Charmin?  It would be a very good thing to have the injectors cleaned.  They could either be stuck closed or open.  In any event cleaning them will get the bike running properly faster than trying to run the bike with fuel system cleaner in the fuel.

The key position is correct.  The folding key has a triangle pointer molded in the plastic under the BMW roundel.  when the key is folded it will point at the correct position on the label.

Gryphon do you have any experience taking the rail out and testing the injectors? I saw a video where the injectors were attached to the rail pulled out from the bike and the guy was pressing start with the injectors spraying into a pan. Is that a way to test them and is the process taking them off involved?
In another post I had mentioned a source I found Mr. Injector will do them for $17.50 each.

About the key, funny how you miss little things. I did see how it folds so that is how it is used so it points to the right position. It actually shows that in the K100 Riders Manual but I am so used to using a key in the upright position that when in that position it points to ON when it is OFF, and to the 3 o'clock position when it is ON. I think I will fold it from now on so I feel better.


* Ignition K100.JPG (24.56 kB . 324x332 - viewed 96 times)


  • Wappingers Falls, New York
  • 1987 K100RS
"The first to present his case seems right, till another comes forward and questions him". Proverbs 18:17

Offline Martin

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Re: Awakening 1987 K100RS from 10 year slumber.
« Reply #95 on: July 09, 2019, 02:06:16 PM »
Be extremely careful when testing injectors. Any stray sparks or naked flames could result in personal damage or more importantly damage to your Brick. Do not smoke while doing this, and a fire extinguisher or a fireman is a good standby.
Regards Martin.
  • North Lakes Queensland Australia
  • 1992 K75s Hybrid, Lefaux, Vespa V twin.

Offline SpecialK

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Re: Awakening 1987 K100RS from 10 year slumber.
« Reply #96 on: July 09, 2019, 05:48:52 PM »
Gryphon do you have any experience taking the rail out and testing the injectors? I saw a video where the injectors were attached to the rail pulled out from the bike and the guy was pressing start with the injectors spraying into a pan. Is that a way to test them and is the process taking them off involved?

I am certain I will not be trying this.

It would be a very good thing to have the injectors cleaned.  They could either be stuck closed or open.  In any event cleaning them will get the bike running properly faster than trying to run the bike with fuel system cleaner in the fuel.

more likely will try this.
  • Wappingers Falls, New York
  • 1987 K100RS
"The first to present his case seems right, till another comes forward and questions him". Proverbs 18:17

Offline Laitch

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Re: Awakening 1987 K100RS from 10 year slumber.
« Reply #97 on: July 10, 2019, 09:45:48 AM »
. . . or more importantly damage to your Brick.
:giggles
  • Along the Ridley in Vermont.
  • 1995 K75 72,000 miles
I wept because I had no radials until I met a man who had no splines.
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Offline SpecialK

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  • Posts: 98
Re: Awakening 1987 K100RS from 10 year slumber.
« Reply #98 on: July 11, 2019, 05:08:29 PM »
Today I removed the fuel rail and injectors. Not too difficult but the wire clips holding on the electrical connectors were a pain to get off, nowhere to grab them. I ended up using a fine pointed pick to get the end to come out from the grey connector, then grabbed that with a small needle nose plier. Then removed the square clips holding the injectors to the rail

I popped the rail off first then vacuumed around each injector then grabbed each injector with a channel lock plier with a rag wrapped around so as not to scratch the injector. I felt like a dentist trying to pull a wisdom tooth but they all came out without too much trouble.

Cleaned the rail with carb cleaner. There was a little old gas varnish in there but looked like the gas I put in was getting through. It was not clogged.

Called Mr. Injector and he explained the procedure to me. $17.50 X 4 = $70 + $15.00 Priority flat rate small box both ways = $85 so off they go tomorrow. Should have them back in about 10 days.

Not much to do until then.

Rail and injectors

* IMG_0002.JPG (60.85 kB . 768x576 - viewed 74 times)

Electrical connectors with rag over injector ports

* IMG_0005.JPG (76.51 kB . 768x576 - viewed 76 times)
  • Wappingers Falls, New York
  • 1987 K100RS
"The first to present his case seems right, till another comes forward and questions him". Proverbs 18:17

Offline The Mighty Gryphon

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Re: Awakening 1987 K100RS from 10 year slumber.
« Reply #99 on: July 11, 2019, 11:46:33 PM »
You now have 10 days to pull the throttle bodies and check for cracks in the rubber bushings above and below them.  Any cracks will allow air leaks that will mess up the running of the engine.
  • In my garage in Marilla, NY
  • '94 K75RT Mystic Red, '91K100RS White/Blue, '89 K100RS Special edition White/Blue
Current:
'94 K75RT "Ilsa, She Wolf of the SS"
'91 K100RS "Moby Brick Too
'89 K100RS SE

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