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1Back to top Go down    Fuel regulator and fuel smell on Sat Jul 28, 2018 6:56 am

nobbylon

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Heavy smell of fuel yesterday so Iíve stripped the airbox out to investigate.†
2 questions if I may gents?
1/ the line going into the top of the regulator swivels as if on an o ring seal, is this correct
2/ I assumed the system would or should remain pressurized even when not rumming. I took the lines off of the tank and no pressure or fuel spray and this could possibly be why it takes a few cranks to get it started ie building fuel pressure.†

thanks all, john

    

2Back to top Go down    Re: Fuel regulator and fuel smell on Sat Jul 28, 2018 7:21 am

nobbylon

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ok got my own answer to question 1, fuel lines loose on both supply and return on the regulator.
Still wondering if the system should stay pressurized though.

    

3Back to top Go down    Re: Fuel regulator and fuel smell on Sat Jul 28, 2018 7:24 am

RicK G

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If that is lose then I would strongly recommend replacing all the fuel lines. They are probably 30 years old.

    

4Back to top Go down    Re: Fuel regulator and fuel smell on Sat Jul 28, 2018 7:35 am

nobbylon

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Thatís the plan Rick. Should it maintain pressure, ok not 36 but atleast some residual?

    

5Back to top Go down    Re: Fuel regulator and fuel smell on Sat Jul 28, 2018 11:01 am

RicK G

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In theory they should hold pressure for quite some hours but I have found that even 10 minutes will cause the pressure to fall away significantly.
Usually when starting from cold tap the start button, this will make the pump to run for 1.5 seconds and will prime the system then hit it to start and it will usually fire very quickly. My K100 and K1100 always needed priming but the K75 usually doesn't need it if the engine is the slightest bit warm† it will fire almost instantly.

    

6Back to top Go down    Re: Fuel regulator and fuel smell on Sat Jul 28, 2018 11:15 am

nobbylon

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Frustration is just not a big enough word!†
Replaced all fuel lines and now the bike will hardly idle and tries to die if I open the throttle. If I feather the throttle I can get it off idle. Itís worse now than before. Flow meter door is working, no fuel leaks. Return to tank side of the regulator is flowing fuel. Can these injections get air locks? Any idea fellas?

    

7Back to top Go down    Re: Fuel regulator and fuel smell on Sat Jul 28, 2018 12:07 pm

robmack

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The fuel lines you chose, do they have FI pressure rating? Are there any sharp bends that may be collapsing, restricting the fuel flow? This was a problem for another member here. http://www.k100-forum.com/t13394-collapsing-fuel-return-line

http://k75retro.blogspot.ca/
    

8Back to top Go down    Re: Fuel regulator and fuel smell on Sat Jul 28, 2018 12:44 pm

nobbylon

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pressure rating is 10 bar so more than enough. no kinks. removed injectors and will check them tomorrow. Will try another fuel regulator I have tomorrow and a different ecu.


__________________________________________________
K100RS July 1989
K100 Dec 1983†
R90s June 1975
R75/6 Feb 1976
F650GD May 2001
    

9Back to top Go down    Re: Fuel regulator and fuel smell on Sat Jul 28, 2018 1:08 pm

Laitch

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@nobbylon wrote:Frustration is just not a big enough word!†
Any idea fellas?
How about Exasperation? It has five syllables, two additional vowels and an additional letter.

Give the clamps another tightening, too.


__________________________________________________
1995 K75T 68,000 miles
    

10Back to top Go down    Re: Fuel regulator and fuel smell on Sat Jul 28, 2018 1:16 pm

nobbylon

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_injectors are all 16.6-7 ohms. will check the spray tomorrow. Fortunately I have the other K to try bits from.


__________________________________________________
K100RS July 1989
K100 Dec 1983†
R90s June 1975
R75/6 Feb 1976
F650GD May 2001
    

11Back to top Go down    Re: Fuel regulator and fuel smell on Sat Jul 28, 2018 3:52 pm

charlie99

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@nobbylon wrote:pressure rating is 10 bar so more than enough. no kinks. removed injectors and will check them tomorrow. Will try another fuel regulator I have tomorrow and a different ecu.

question ...you do have the correct orientation of the fuel lines at the tank ?

the tank rear spigot (high pressure) line†does go directly to the fuel rail ...the front tank spigot is the return from regulator output (top fpr spigot )


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

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

12Back to top Go down    Re: Fuel regulator and fuel smell on Sun Jul 29, 2018 2:10 am

nobbylon

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fuel lines are connected correctly yes.


__________________________________________________
K100RS July 1989
K100 Dec 1983†
R90s June 1975
R75/6 Feb 1976
F650GD May 2001
    

13Back to top Go down    Re: Fuel regulator and fuel smell on Sun Jul 29, 2018 2:32 am

charlie99

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

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

14Back to top Go down    Fuel Regulator and fuel smell on Sun Jul 29, 2018 2:52 am

Tom FKR

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Fuel filter Blocked?? Fuel escaping from the O ring at bottom of tank?? Just clutching at straws. Cheers Tom


__________________________________________________
1993 K75 Slightly Modified
2010 BMW F650GS Twin
1992 R100R
    

15Back to top Go down    Re: Fuel regulator and fuel smell on Sun Jul 29, 2018 5:48 am

nobbylon

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Thank you to all for suggestions.
Normality is restored and this may help someone. After changing the injectors, swapping out the ecu and air flow meter the bike just would not pull away from idle, bucking like a bronco.
I donít know why I did, possibly in an atempt to check if the line was pinched but I squeezed the FRONT fuel line at the tank and held it closed for a few seconds while attempting to rev the bike and it just burst into life again. Starts instantly on the button and throttle response is now instant! Rides and pulls clean once more.
Could it have been an air lock in the pump, filter, fuel reg?†
Camping is back on with the RS! Plus with the new fuel lines the fuel smell has gone†Very Happy


__________________________________________________
K100RS July 1989
K100 Dec 1983†
R90s June 1975
R75/6 Feb 1976
F650GD May 2001
    

16Back to top Go down    Re: Fuel regulator and fuel smell on Sun Jul 29, 2018 7:46 am

Dai

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My guess: the one-way valve in the fuel tank was corroded partly closed and squeezing the tube built up enough pressure to shift it. If the tank starts rattling, the spring in the valve has broken and what you can hear will be the ball bearing being pulsed by the fuel pump. It's not a show-stopper but when you remove the fuel line to fix the (hypothetical) rattle, remember to either run the tank low or empty it first.

Oddly enough, I have one of those valves on my desk in front of me!


__________________________________________________
'83 K100 upgraded to K100RS spec
Others...
'78 Moto Guzzi 850-T3, '79 Moto Guzzi 850-T3 California,'93 Moto Guzzi 1100ie California,
'03 Suzuki Blandit GSF600SK3 (NFS any more because wifey has claimed it)
    

17Back to top Go down    Re: Fuel regulator and fuel smell on Sun Jul 29, 2018 10:56 am

nobbylon

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thanks for the info Dai. Rebuilt the silver one back up and they both start and run fine so far.


__________________________________________________
K100RS July 1989
K100 Dec 1983†
R90s June 1975
R75/6 Feb 1976
F650GD May 2001
    

18Back to top Go down    Re: Fuel regulator and fuel smell on Sun Jul 29, 2018 12:52 pm

Point-Seven-five

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I suspect you may have a failing fuel pressure regulator that was not providing enough/consistent fuel pressure at the injectors.† This may have been caused by the dump valve inside the regulator being stuck in the open position.† Pinching the return line may have created enough back pressure to seat the valve in the regulator while boosting the pressure enough to provide the fuel flow through the injectors to allow for proper acceleration.

If it were my bike, I would be thinking seriously about having a spare regulator on hand and being prepared to install it the next time the problem appears.† Of course, having a spare will insure that you will NEVER have that problem again.


__________________________________________________
Present:
1994 K75RT
1994 K75S
1992 K100RS

Past:
1982 Honda FT500
1979 Honda XR185
1977 Honda XL125
1974 Honda XL125
1972 OSSA Pioneer 250
1968 Kawasaki 175
    

19Back to top Go down    Re: Fuel regulator and fuel smell on Sun Jul 29, 2018 1:18 pm

92KK 84WW Olaf

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@Point-Seven-five wrote:I suspect you may have a failing fuel pressure regulator that was not providing enough/consistent fuel pressure at the injectors.† This may have been caused by the dump valve inside the regulator being stuck in the open position.† Pinching the return line may have created enough back pressure to seat the valve in the regulator while boosting the pressure enough to provide the fuel flow through the injectors to allow for proper acceleration.

If it were my bike, I would be thinking seriously about having a spare regulator on hand and being prepared to install it the next time the problem appears.† Of course, having a spare will insure that you will NEVER have that problem again.

I agree wholeheartedly with this.

I had what I thought was a fault regulator so bought one. Of course that meant the problem fixed itself.


__________________________________________________
1992 K100LT 0193214 Alaska Blue 101,000 miles
1984 K100RT 0022575 Baja Red bought 36,000 now 89,150 miles
1997 K1100LT 0188024 Mystic Red 58,645 now 74,700 miles
    

20Back to top Go down    Re: Fuel regulator and fuel smell on Sun Jul 29, 2018 5:00 pm

nobbylon

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Does having a spare K100 count? I will start them both from cold in the morning but hopeful itís sorted.


__________________________________________________
K100RS July 1989
K100 Dec 1983†
R90s June 1975
R75/6 Feb 1976
F650GD May 2001
    

21Back to top Go down    Re: Fuel regulator and fuel smell on Mon Jul 30, 2018 9:12 pm

Point-Seven-five

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For best results, it really needs to be in the tail cowl.


__________________________________________________
Present:
1994 K75RT
1994 K75S
1992 K100RS

Past:
1982 Honda FT500
1979 Honda XR185
1977 Honda XL125
1974 Honda XL125
1972 OSSA Pioneer 250
1968 Kawasaki 175
    

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