BMW K bikes (Bricks)


You are not connected. Please login or register

View previous topic View next topic Go down  Message [Page 1 of 1]


1Back to top Go down    Help me start this bike - 93 K11RS on Sun Sep 18, 2016 11:58 pm

duck

avatar
Life time member
Life time member
I bought an abandoned 93 RS for parts the other day. (I bought it legally from a real shop and its abandoned status is properly documented with the Dept. of Licensing.) It's got 105K miles and has seen some better days Sad but it does have a decent Works Performance shock and Staintune exhaust.

So far:

- The cluster lights up and the fuel pump primes like it should when the ignition is turned on. (With a screwdriver. affraid )

- The inside of the tank is very clean and the gas looks good.

- The clutch cable is broken but when I pull in the clutch lever and hit the start button the starter relay clicks so I know that's working. But that's all it does.

- Aside from the cluster, neither the headlight nor tail light come on when it is turned on.

- I replaced all of the little black relays thinking the load shed might be bad but that didn't help.

- Also swapped in a new starter relay.

- When I tested the voltage on the top of the starter it reads 12V even when the starter button isn't pushed. Shouldn't that only be 12V when the starter relay is engaged?

- I'm pretty sure the transmission is in neutral by shifting the lever but the gear indicator is stuck on 3 so that switch is probably shot.

Given the 12V reading at the starter I'm thinking maybe it needs a new starter. Question


Since it's a parts bike I don't plan to spend a whole lot more time and effort on it but I'd like to get it running just for the heck of it.

Anybody got any clues on this puzzle bike?


__________________________________________________
Current stable:
86 Custom K100 (standard fairing, K75 Belly pan, Ceramic chromed engine covers, paralever)
K75 Frankenbrick (Paralever, K11 front end, hybrid ABS, K1100RS fairing, radial tires)
86 K75C Turbo w/ paralever
94 K1100RS
93 K1100LT (x2)
91 K1
93 K75S (K11 front end)
91 K75S
14 Yamaha WR250R
http://www.ClassicKBikes.com
    

2Back to top Go down    Re: Help me start this bike - 93 K11RS on Mon Sep 19, 2016 12:38 am

RicK G

avatar
VIP
VIP
The output terminal on the start relay should only have 12v when the starter button is pressed, if it has that 12v then the next step is the starter itself. Give the starter body a gentle tap with a hammer handle, if it starts the brushes is probably the problem.


__________________________________________________
If everything seems under control then you aint goin fast enough:- Mario Andretti
Bikes 1986 K100RT, 1993 K1100 LT, 1994 K1100 LT, 1993 K75 RT, 1996 K75RT, 1986 K75 GS, 1979 Z1300 Kawasaki X 2 & 1976 SR 500 Yamaha for now
    

3Back to top Go down    Re: Help me start this bike - 93 K11RS on Mon Sep 19, 2016 1:06 am

Holister

avatar
Life time member
Life time member
Agree with that.

So if you get 12V whether the start button is pressed or not, then the relay contacts are probably welded. I think the clicking noise you are hearing is possibly the LSR. Pull the starter relay cover off and check the contacts. It might just have a small bead of metal arcing across.


__________________________________________________
1988 K100RT VIN No. 0094680
1989 K100RT VIN No. 0097367 (naked)
1996 K1100RS VIN No. 0451808
Fuel: 95 Octane
Engine Oil:Nulon Full Synthetic 15W50
Gear Box Oil: Nulon Synthetic 75W90
    

4Back to top Go down    Re: Help me start this bike - 93 K11RS on Mon Sep 19, 2016 8:04 am

robmack

avatar
Life time member
Life time member
But Duck said that he has already replaced the starter relay with a new one, so it eliminates the welded contacts theory (unless the new relay is also rubbish). I'd suspect the starter motor. It's easy enough to pull and test on the bench. Also, put a voltmeter on the starter relay coils to prove your conjecture that the relay is functioning when the clutch is pulled and start button pressed; it will confirm its function.


__________________________________________________
Robert
1987 K75 @k75retro.blogspot.ca
2011 Moto Guzzi V7 Racer
http://k75retro.blogspot.ca/
    

5Back to top Go down    Re: Help me start this bike - 93 K11RS on Mon Sep 19, 2016 8:40 am

Holister

avatar
Life time member
Life time member
Not disputing the suspect starter motor but that doesn't explain the constant 12V output from the relay. But as you say Rob, a voltmeter across the relay coil will tell if its a fault in the starter circuit.
Is it possible that the st. motor is stuck or has an earth short. That would possibly fry the relay contacts pretty quick. Just some thoughts.
Cheers


__________________________________________________
1988 K100RT VIN No. 0094680
1989 K100RT VIN No. 0097367 (naked)
1996 K1100RS VIN No. 0451808
Fuel: 95 Octane
Engine Oil:Nulon Full Synthetic 15W50
Gear Box Oil: Nulon Synthetic 75W90
    

6Back to top Go down    Re: Help me start this bike - 93 K11RS on Mon Sep 19, 2016 8:47 am

Avenger GT

avatar
Life time member
Life time member
@Holister wrote:Not disputing the suspect starter motor but that doesn't explain the constant 12V output from the relay. But as you say Rob, a voltmeter across the relay coil will tell if its a fault in the starter circuit.
Is it possible that the st. motor is stuck or has an earth short. That would possibly fry the relay contacts pretty quick. Just some thoughts.
Cheers
Suspect No.1 is the starter motor brushes. Since the starter is used to ground the load shed relay, if there is no continuity through it you will get 12V permanently on the input.

    

7Back to top Go down    Re: Help me start this bike - 93 K11RS on Mon Sep 19, 2016 9:06 am

charlie99

avatar
VIP
VIP
aye agree


__________________________________________________
cheezy grin whilst riding, kinda bloke ....oh the joy !!!! ...... ( brick aviator )

'86 K100 RT..#0090401 ..."Gerty" ( Gertrude Von Clickandshift ) --------O%O
    

8Back to top Go down    Re: Help me start this bike - 93 K11RS on Mon Sep 19, 2016 9:23 am

Holister

avatar
Life time member
Life time member
OK. Back to the schematics to get my head around that. Laughing Cheers


__________________________________________________
1988 K100RT VIN No. 0094680
1989 K100RT VIN No. 0097367 (naked)
1996 K1100RS VIN No. 0451808
Fuel: 95 Octane
Engine Oil:Nulon Full Synthetic 15W50
Gear Box Oil: Nulon Synthetic 75W90
    

9Back to top Go down    Re: Help me start this bike - 93 K11RS on Mon Sep 19, 2016 10:38 am

kioolt

avatar
Silver member
Silver member
Avenger GT is right about having 12 volts at the starter if the starter is bad. What you have is a series circuit that flows through the load shed relay and the starter. With the starter not passing any or little current that makes it have a high resistance. A resistance that is much higher then the load shed relay coil. In a series circuit the voltage will be proportional to the resistance of the individual components. Since the starter has the highest resistance it will have the highest voltage. In this case the resistance is so much higher it will be all across the starter.


__________________________________________________
2004 R1150RT 183,000 miles
1991 K100LT 128,700 miles
1982 R100RT 106,900 miles
Total418,600 BMW miles

AMA,BMWRA,BMWMOA


The cheapest thing on a BMW is the nut that connects the handlebars to the seat.
    

10Back to top Go down    brushes on Mon Sep 19, 2016 10:50 am

kennybob

avatar
Silver member
Silver member
The brushes in the starter are not making contact, so the circuit path thru the windings and brushes is open. So the LSR is not pulled closed and thus the headlights are not working since they get their power thru the load shed relay contacts.

    

11Back to top Go down    Re: Help me start this bike - 93 K11RS on Mon Sep 19, 2016 11:25 am

duck

avatar
Life time member
Life time member
So it sounds like there is consensus that my suspicion about the starter motor being the culprit may be correct.

Although I know the starter does some weird electrical voodoo I must admit that I don't completely understand how that part of K electronics works - or doesn't.

And thanks for pointing out that it could also be the root cause for the lights not working. That hadn't occurred to me but now that you point it out that makes sense - sort of.

Kind of drizzling here today and the bike is still strapped onto my trailer (which serves as a wonderful outdoor motorcycle lift) so it may be a day or so until I can swap in another starter.

On a related topic, after doing some electrical stuff on my 86 K100 I put the recently revived tank back on yesterday only to discover that it has a massive leak caused by the water that sat it. Curiously, it's not leaking at the weld seam at the bottom as I'd expect but it actually ate a hole affraid through the aluminum wall (and then paint) about an inch up from the bottom left low point. But once I get the parts K1100 started I can steal the tank from that to use on the K100. sunny

A Mystic Red tank on a black bike should look interesting but getting it repainted black to match the bike color shouldn't be cost prohibitive.


__________________________________________________
Current stable:
86 Custom K100 (standard fairing, K75 Belly pan, Ceramic chromed engine covers, paralever)
K75 Frankenbrick (Paralever, K11 front end, hybrid ABS, K1100RS fairing, radial tires)
86 K75C Turbo w/ paralever
94 K1100RS
93 K1100LT (x2)
91 K1
93 K75S (K11 front end)
91 K75S
14 Yamaha WR250R
http://www.ClassicKBikes.com
    

12Back to top Go down    Try this - on Mon Sep 19, 2016 1:14 pm

Bumblebee

avatar
Silver member
Silver member
Take a jumper cable from the positive (+) side of the battery directly to the starter terminal on the motor. Engine crank? If so the starter is good, if not the starter is bad.

B4 you do this the engine must be in neutral and the bike should be on the center stand. When you jump the starter directly like all the safety interlocks are defeated, if the starter works and the bike is on the side stand and in gear the starter will crank the bike right off the stand and fall over. Bad.

http://Bugsmashers.org/phpbb
    

13Back to top Go down    Re: Help me start this bike - 93 K11RS on Mon Sep 19, 2016 1:57 pm

duck

avatar
Life time member
Life time member
What is the point in jumping a starter terminal that already reads 12V? Besides, getting anything to that starter terminal with a 93 battery holder base is hard because the ignition amp is in the way.

I'm pretty sure that it's in N. It is strapped onto a trailer with four tie-downs. I just plan to see if the starter motor will turn. On the off chance that it is in gear, a quick tap on the start button should just make it lurch a little.

If that works and it does happen to be in gear then I'll take off the tie-downs and put it on the center stand and make sure it's in N since the rear wheel will spin by hand on the center stand.


__________________________________________________
Current stable:
86 Custom K100 (standard fairing, K75 Belly pan, Ceramic chromed engine covers, paralever)
K75 Frankenbrick (Paralever, K11 front end, hybrid ABS, K1100RS fairing, radial tires)
86 K75C Turbo w/ paralever
94 K1100RS
93 K1100LT (x2)
91 K1
93 K75S (K11 front end)
91 K75S
14 Yamaha WR250R
http://www.ClassicKBikes.com
    

14Back to top Go down    Re: Help me start this bike - 93 K11RS on Mon Sep 19, 2016 2:04 pm

kennybob

avatar
Silver member
Silver member
@duck wrote:...
only to discover that it has a massive leak caused by the water that sat it. Curiously, it's not leaking at the weld seam at the bottom as I'd expect but it actually ate a hole affraid through the aluminum wall (and then paint) about an inch up from the bottom left low point.

That's what i've found on a couple of my tanks--the seams are fine, but the worst corrosion occurs at the high water line where the fuel and water meet. On other websticle forums they thought it was polymers and acids forming from the fuel-ethanol-water-aluminum combination and it has the most intense corrosive activity at the water-fuel interface.

    

15Back to top Go down    Re: Help me start this bike - 93 K11RS on Mon Sep 19, 2016 2:51 pm

duck

avatar
Life time member
Life time member
Hmmm... The triple-whammy hypothesis does seem to correlate with empirical data.

Even if it is the wrong color, I'm glad that I have an extra tank to use on hand.

I tried fixing a K75 tank many moons ago with some J-B Weld stuff and though it did work it only lasted about a year.


__________________________________________________
Current stable:
86 Custom K100 (standard fairing, K75 Belly pan, Ceramic chromed engine covers, paralever)
K75 Frankenbrick (Paralever, K11 front end, hybrid ABS, K1100RS fairing, radial tires)
86 K75C Turbo w/ paralever
94 K1100RS
93 K1100LT (x2)
91 K1
93 K75S (K11 front end)
91 K75S
14 Yamaha WR250R
http://www.ClassicKBikes.com
    

16Back to top Go down    Re: Help me start this bike - 93 K11RS on Mon Sep 19, 2016 2:52 pm

Avenger GT

avatar
Life time member
Life time member

@duck wrote:What is the point in jumping a starter terminal that already reads 12V? Besides, getting anything to that starter terminal with a 93 battery holder base is hard because the ignition amp is in the way.


If that works and it does happen to be in gear then I'll take off the tie-downs and put it on the center stand and make sure it's in N since the rear wheel will spin by hand on the center stand.
The 12V at the starter is coming through the coil of the load shed relay, which is only capable of passing a few milliamps of current. The starter needs the bones of a couple of hundred amps to turn it, so the voltage from the L.S.R. will do nothing to it. When everything is working properly the current path through the starter motor is in reality a short circuit to the load shed relay. If you measure the voltage on the starter on a working bike before you press the start button, you will find that it is practically zero. The 12V you are measuring at the starter on the faulty bike is coming from the negative side of the coil in the L.S.R. It is only present because the path to earth through the starter motor is open circuit. I hope the added diagram helps to show what goes on.



Last edited by Avenger GT on Mon Sep 19, 2016 3:34 pm; edited 1 time in total (Reason for editing : To add diagram.)

    

17Back to top Go down    Re: Help me start this bike - 93 K11RS on Mon Sep 19, 2016 6:52 pm

duck

avatar
Life time member
Life time member
Big thumb

SWEET! Installed a different starter motor: headlight and tail light now work and she fired right up and runs like a top. (Once I remembered to hook the Motronic back up. Embarassed)

Thanks for the input, guys. I kind of suspected a bad starter motor when it read 12V but it's always nice to get some confirmation.


__________________________________________________
Current stable:
86 Custom K100 (standard fairing, K75 Belly pan, Ceramic chromed engine covers, paralever)
K75 Frankenbrick (Paralever, K11 front end, hybrid ABS, K1100RS fairing, radial tires)
86 K75C Turbo w/ paralever
94 K1100RS
93 K1100LT (x2)
91 K1
93 K75S (K11 front end)
91 K75S
14 Yamaha WR250R
http://www.ClassicKBikes.com
    

18Back to top Go down    Re: Help me start this bike - 93 K11RS on Mon Sep 19, 2016 8:45 pm

RicK G

avatar
VIP
VIP
I just had the tank on my recently purchased K75RT welded and there were 5 holes, one about an inch up where you said.
I think it is because that is the level of the water and the interface line between fuel and water is where the electrolisis takes hold first


__________________________________________________
If everything seems under control then you aint goin fast enough:- Mario Andretti
Bikes 1986 K100RT, 1993 K1100 LT, 1994 K1100 LT, 1993 K75 RT, 1996 K75RT, 1986 K75 GS, 1979 Z1300 Kawasaki X 2 & 1976 SR 500 Yamaha for now
    

19Back to top Go down    Re: Help me start this bike - 93 K11RS on Mon Sep 19, 2016 10:01 pm

duck

avatar
Life time member
Life time member
Avenger: Thanks for the explanation on the starter electronics. I understand it a little better now.


__________________________________________________
Current stable:
86 Custom K100 (standard fairing, K75 Belly pan, Ceramic chromed engine covers, paralever)
K75 Frankenbrick (Paralever, K11 front end, hybrid ABS, K1100RS fairing, radial tires)
86 K75C Turbo w/ paralever
94 K1100RS
93 K1100LT (x2)
91 K1
93 K75S (K11 front end)
91 K75S
14 Yamaha WR250R
http://www.ClassicKBikes.com
    

20Back to top Go down    Re: Help me start this bike - 93 K11RS on Tue Sep 20, 2016 12:01 am

Holister

avatar
Life time member
Life time member
Likewise. Thanks.
like


__________________________________________________
1988 K100RT VIN No. 0094680
1989 K100RT VIN No. 0097367 (naked)
1996 K1100RS VIN No. 0451808
Fuel: 95 Octane
Engine Oil:Nulon Full Synthetic 15W50
Gear Box Oil: Nulon Synthetic 75W90
    

21Back to top Go down    Re: Help me start this bike - 93 K11RS on Tue Sep 20, 2016 12:50 am

Brad-Man

avatar
Life time member
Life time member
This is a prime example of why I love this forum.

I can halfway read a wiring diagram, but in no way understand what I am seeing enough to diagnose anything other than dicontinuity or crossed connections.

Avenger's post was great!

There is no way I would have been able to look at a schematic and understand what he made plain.

Thanks so much!


__________________________________________________
Toys don't make the man - Man makes the toys....
    

22Back to top Go down    Re: Help me start this bike - 93 K11RS on Tue Sep 20, 2016 2:22 pm

Avenger GT

avatar
Life time member
Life time member
Glad to be of service.

    

Sponsored content


    

View previous topic View next topic Back to top  Message [Page 1 of 1]

Permissions in this forum:
You cannot reply to topics in this forum