BMW K bikes (Bricks)

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Shoei

Shoei
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Hi Guys,

I have just rebuilt the engine on a bike which my son stripped down a couple of years ago.
It is now together enough to start. I have decent compression, oil pressure and sparks, but the injectors are not, erm, injecting.
The neutral switch is broken, so according to the neutral light, it is in gear.
My question is that if the clutch is in, but the bike is in gear, would that cut the fuel inection syatem?
I'm hoping so, as that would explain it not starting.

Thanks in advance.



Last edited by Shoei on Wed Mar 17, 2021 11:51 am; edited 1 time in total

    

Rick G

Rick G
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It should but make sure the plunger switch behind the clutch lever is operating other wise the ICU still thinks the clutch lever is out.


__________________________________________________
"Man sacrifices his health in order to make money.
Then he sacrifices money to recuperate his health.
And then he is so anxious about the future that he does not enjoy the present; the result being that he does not live in the present or the future; he lives as if he is never going to die, and then dies having never really lived."   Dalai Lama


Bikes 2004 K1200GT 1998 K1100 LT, 1986 K75 GS.
    

Shoei

Shoei
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Thanks Rick,

The clutch switch is working. When depressed, it won't turn over at all.
When not depressed, it turns over but I have no fuel from the injectors, although the fuel pump is working.

    

Rick G

Rick G
admin
admin
Go to the Portal page then to the tech page and under Misc you will see a flow chart for the bike not starting.


__________________________________________________
"Man sacrifices his health in order to make money.
Then he sacrifices money to recuperate his health.
And then he is so anxious about the future that he does not enjoy the present; the result being that he does not live in the present or the future; he lives as if he is never going to die, and then dies having never really lived."   Dalai Lama


Bikes 2004 K1200GT 1998 K1100 LT, 1986 K75 GS.
    

Shoei

Shoei
active member
active member
Awesome, thanks Rick.
I wasn't sure how to test the injectors and the fuel control unit, so that is super helpful.

Hopefully, I will have some good news in a day or two. Will a K100 start in gear with the clutch in? 112350

    

Laitch

Laitch
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Shoei wrote:I have just rebuilt the engine on a bike which my son stripped down a couple of years ago.
While you've been at it, did you replace the fuel filter and fuel lines in the tank, then check that fuel was being delivered under pressure at the fuel rail?


__________________________________________________
1995 K75 81,000 miles
Will a K100 start in gear with the clutch in? Usa-lo10
    

Shoei

Shoei
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I haven't had the pump out of the tank yet.
I'm just trying to get it running before I rip it apart again to start the rebuild.
I haven't checked the actual pressure as yet, but it's coming through pretty quickly.

    

8Back to top Go down   Will a K100 start in gear with the clutch in? Empty No go Wed Mar 17, 2021 9:32 pm

daveyson

daveyson
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"will a k100 start in gear with the clutch in"

It should since power to the start button then bypasses the gear switch by a circuit through the clutch switch to the start button.

If the injectors aren't making a ticking sound, you might have an electrical problem.


__________________________________________________
11/1985 bmw k100rt (late model)  Vin. 0090567
 ~120,000 km
    

92KK 84WW Olaf

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You need to tell us engine type. 4v engine has a side stand cut out.


__________________________________________________
1992 K100LT 0193214 Bertha Blue 101,000 miles
1984 K100RT 0022575 Brutus Baja Red 578 bought 36,000 now 89,150 miles
1997 K1100LT 0188024 Wotan Mystic Red 689 58,645 now 106,950 miles Deceased.
1983 K100RS 0011171 Fricka 606 Alaska Blue 29,495 miles Damn K Pox Its a Bat outta Hell Now 49,840 miles. 
1996 K1100LT 0233004 Lohengrin Mystic Red 38,000 miles currently 42,640 miles.

Past:
1968 Yamaha 80 YG1
1971 Yamaha 125 YAS-1
1968 Honda 125 SS
1970 Honda CD 175
1973 Honda CB500-4
Honda CX 500
    

Laitch

Laitch
Life time member
Life time member
92KK 84WW Olaf wrote:You need to tell us engine type. 
His profile indicates it's a caffeinated K100LT so that eliminates 4V.


__________________________________________________
1995 K75 81,000 miles
Will a K100 start in gear with the clutch in? Usa-lo10
    

92KK 84WW Olaf

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Life time member
Life time member
Laitch wrote:
92KK 84WW Olaf wrote:You need to tell us engine type. 
His profile indicates it's a caffeinated K100LT so that eliminates 4V.
I did not look in there......

But...cafed could mean the clutch switch cable is accidentally incorrectly connected to the loom as front or rear brake or choke cable or clutch connectors are identical as they are the same switches.


__________________________________________________
1992 K100LT 0193214 Bertha Blue 101,000 miles
1984 K100RT 0022575 Brutus Baja Red 578 bought 36,000 now 89,150 miles
1997 K1100LT 0188024 Wotan Mystic Red 689 58,645 now 106,950 miles Deceased.
1983 K100RS 0011171 Fricka 606 Alaska Blue 29,495 miles Damn K Pox Its a Bat outta Hell Now 49,840 miles. 
1996 K1100LT 0233004 Lohengrin Mystic Red 38,000 miles currently 42,640 miles.

Past:
1968 Yamaha 80 YG1
1971 Yamaha 125 YAS-1
1968 Honda 125 SS
1970 Honda CD 175
1973 Honda CB500-4
Honda CX 500
    

Shoei

Shoei
active member
active member
Thanks guys,

Yes, it is an 8 valve 87 LT, which made lapping the valves considerably quicker than what I'm used to. Very Happy 

I have checked the injectors and 2 are firing and 2 are not. They have all had a session in an ultrasonic bath, so I assume the 2 that are not working are f****d?
The fuel pump is working, but I'm not sure if I have enough pressure from it, so will be ordering a fuel pressure test gauge.
If I have low fuel pressure, is that likely to be down to fuel pump or could it be the pressure valve thingy on top of the throttle bodies?

Sorry for all the questions, but I am more accustomed to analogue fuel injection (carbs).

    

92KK 84WW Olaf

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Life time member
Life time member
Shoei wrote:Thanks guys,

Yes, it is an 8 valve 87 LT, which made lapping the valves considerably quicker than what I'm used to. Very Happy 

I have checked the injectors and 2 are firing and 2 are not. They have all had a session in an ultrasonic bath, so I assume the 2 that are not working are f****d?
The fuel pump is working, but I'm not sure if I have enough pressure from it, so will be ordering a fuel pressure test gauge.
If I have low fuel pressure, is that likely to be down to fuel pump or could it be the pressure valve thingy on top of the throttle bodies?

Sorry for all the questions, but I am more accustomed to analogue fuel injection (carbs).
Important first to check the cylinders of the injectors not firing. If you did the test on bench etc your diagnosis is likely correct. If you did it in the bike trying to run it and its showing up and 1 and 4 or 2 and 3 then your problem is very likely to be elsewhere and electrical. If this is the case maybe a Hall Effect Sensor [HES] related issue or the connectors on that line.


__________________________________________________
1992 K100LT 0193214 Bertha Blue 101,000 miles
1984 K100RT 0022575 Brutus Baja Red 578 bought 36,000 now 89,150 miles
1997 K1100LT 0188024 Wotan Mystic Red 689 58,645 now 106,950 miles Deceased.
1983 K100RS 0011171 Fricka 606 Alaska Blue 29,495 miles Damn K Pox Its a Bat outta Hell Now 49,840 miles. 
1996 K1100LT 0233004 Lohengrin Mystic Red 38,000 miles currently 42,640 miles.

Past:
1968 Yamaha 80 YG1
1971 Yamaha 125 YAS-1
1968 Honda 125 SS
1970 Honda CD 175
1973 Honda CB500-4
Honda CX 500
    

Shoei

Shoei
active member
active member
I tested them on the bench, then on the bike to make sure.
2 are definitely faulty, so I have ordered a new set. Just need to check the fuel pressure now.

    

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