Author Topic: How to unstuck a stuck fuel injectors  (Read 503 times)

Offline Martin

  • ^ Quintessential Motobricker
  • Posts: 3872
Re: How to unstuck a stuck fuel injectors
« Reply #25 on: September 10, 2019, 10:20:16 PM »
If the PB doesn't work time to move on and replace. I've got access to a bit more equipment. I did however turn the lid on my wife's sonic jewellery cleaner to try and regress into primordial ooze. It did eventually return to a solid state that sort of resembles a lid. Acrylic lacquer thinner fumes plus plastic = ooze.
Regards Martin.
  • North Lakes Queensland Australia
  • 1992 K75s Hybrid, Lefaux, Vespa V twin.

Offline TommyT

  • New Brick Owner
  • ^ Motobrick Curious
  • Posts: 89
Re: How to unstuck a stuck fuel injectors
« Reply #26 on: September 18, 2019, 09:06:35 AM »
Just an update. I talked to Mr. Injector and he agreed that my injectors are probably beyond saving considering the things I have done to unstick them from the rust inside them. I ordered the Chinese injectors from Ebay for a total of $33. I was hoping to give a report of how they ran but when I installed them and turn on the bike I discovered that the bike's injector rail has a pin sized hole in the cap for the injector for cylinder #3, crap. I had cleaned up the what I though was some surface rust inside of the caps but it must have been deeper the just the surface. I am waiting for a new fuel rail to arrive before I can try them out again.

I am not sure how water got so deep into the fuel system, the bike sat for long time, but I would think the water in the gas would have been confined to the gas tank. Unless someone tried to start the bike after the corn gas attracted water  into the tank and then water being heavier then gas got sucked into the injectors and then the bike sat longer after that to start the rusting of injectors. 
  • Olive NY
  • 1990 K75s, 1990 K75RT

Offline Laitch

  • ^ Quintessential Motobricker
  • Posts: 6932
Re: How to unstuck a stuck fuel injectors
« Reply #27 on: September 18, 2019, 10:29:10 AM »
Unless someone tried to start the bike after the corn gas attracted water  into the tank . . .
Water infiltrated fuel long before the widespread use of ethanol in gasoline. That's why it was recommend to keep fuel tanks topped up in deep winter or in idle vehicles to lessen condensation in fuel tanks. Condensation runs down fuel tank walls then enters the fuel creating multiple problems because water sinks through the fuel to the bottom of the tank and is picked up by the fuel pump. Ethanol combines water with fuel—to a certain extent—so at least water then has a greater chance of leaving the system through combustion. Neglect and idleness are the greatest reasons for component failure, not 10% or less ethanol in fuel.
  • 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.
http://www.motobrick.com/index.php/topic,296.msg53303.html#msg53303

Offline Martin

  • ^ Quintessential Motobricker
  • Posts: 3872
Re: How to unstuck a stuck fuel injectors
« Reply #28 on: September 18, 2019, 05:02:45 PM »
Before ethanol laced fuel we used to actually add a cupful of methylated spirits. The methylated spirits would absorb the water allowing it to be burnt off in the combustion chamber.
Regards Martin.
  • North Lakes Queensland Australia
  • 1992 K75s Hybrid, Lefaux, Vespa V twin.

Offline schrocketeer

  • ^ Motobrick Curious
  • Posts: 66
Re: How to unstuck a stuck fuel injectors
« Reply #29 on: September 19, 2019, 11:21:24 PM »
My 85 k100rt had sat for three years with ethanol included gasoline.

I tried 2 weeks of soaking in Berryman's carb cleaner bucket ($20 from the local auto parts store). No "click" response with 12 Volts across the Leads. Put them back for another week. Still no click. Put them in for a few more days. Happy clicky-opening sounds!

Somewhere else on this forum, there's a list of cars that have compatible o-rings, something like a Chevy Cavalier from the 2000's. Full set for the k100 was less than $4.00.

After I got the fuel tank all cleaned out, and the fuel pump and filter replaced, I connected the fuel injectors in to the rail, but NOT in to the engine. I put a piece of notebook paper under the injectors, then hit the starter. Some nasty orange/brown goo came out right away. Then it started squirting clean gas.

That was 15k miles ago. No fuel issues since.
  • North Alabama
  • 1985 K100RT
Ken   Current: 85 K100RT, 70 CT70, 91 XR250, 97 XR100 Past Bikes: 95 VLX600, 86 TRX250, 02 GZ250, 83 Z50R, 78 ATC90, 86 XR250, 79 XR500, 72 AT1, 75 YZ360, 78 DT400, 75 DT125, 73 Trail 70, Dad's bikes I rode: 69 CL175K3, 71 R5-B

Offline TommyT

  • New Brick Owner
  • ^ Motobrick Curious
  • Posts: 89
Re: How to unstuck a stuck fuel injectors
« Reply #30 on: September 20, 2019, 05:21:39 PM »
My 85 k100rt had sat for three years with ethanol included gasoline.

I tried 2 weeks of soaking in Berryman's carb cleaner bucket ($20 from the local auto parts store). No "click" response with 12 Volts across the Leads. Put them back for another week. Still no click. Put them in for a few more days. Happy clicky-opening sounds!

Somewhere else on this forum, there's a list of cars that have compatible o-rings, something like a Chevy Cavalier from the 2000's. Full set for the k100 was less than $4.00.

After I got the fuel tank all cleaned out, and the fuel pump and filter replaced, I connected the fuel injectors in to the rail, but NOT in to the engine. I put a piece of notebook paper under the injectors, then hit the starter. Some nasty orange/brown goo came out right away. Then it started squirting clean gas.

That was 15k miles ago. No fuel issues since.
That is encouraging, I am still spraying PB Blaster into them hoping to get the same results that you got. I got a number at NAPA for o rings that will fit and new filters for them. I did use the eBay injectors, but I was concern that when I had to pull off the pin holed fuel rail the plastic tips and filters came off with the stuck upper O rings.  They did go back together okay but I did notice the  use of plastic in them. The bike did start up today, but I ran into another surprising problem with the project bike. That will be posted up in another topic soon.
  • Olive NY
  • 1990 K75s, 1990 K75RT

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