Free Flowing Fuel question


Information and questions on GL1200 Goldwings (1984-1987)
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superbill
Posts: 13
Joined: Fri May 02, 2014 9:27 am
Location: Maryville, Tennessee
Motorcycle: 1984 Honda Goldwing Interstate

Free Flowing Fuel question

Post by superbill »



Hello All. I haven't posted much here but have a question involving fuel flow. During the course of getting my '84 GL1200 Interstate ready to ride this year, I've been having an odd issue. After changing out the coolant, I was letting it run with the radiator cap off to let any extra air out. While doing this, the bike died on me after 5 minutes. It's been running perfect until this happened. It would crank right up and run for 4-5 minutes and stop again. Every time, it would crank right up.

Then I came out the next day and found that fuel was overflowing from the carbs. I figured it was a bad carb float. Checked the suspect carb and all was good. While trying to figure this out, I kept having this happen, dying at idle and then had a second occasion of fuel overflowing the carbs. Decided to drain carb bowl #4 and proceeded to drain 51 ounces of fuel. Let it sit the next day and another 16 ounces drained out. At this point I thought it was the gas cap not venting causing pressure build up in the gas tank. So I cleaned the gas cap, soaked it in degreaser, and cleaned it again. Put it on and the bike ran for 20 minutes, just fine, before I shut it off. Took it for a test ride and it seemed sluggish so I decided to do the fuel pump test... attach a hose to the exit barb of the fuel pump, crank it for 5 or 6 seconds and measure how much fuel comes out. However!.. when I attached the hose to the fuel pump exit barb, it proceeded to drain fuel nonstop before I had a chance to crank it over! A steady dripping of fuel, whether the gas cap was on or not. With the gas cap off the gas tank shouldn't that neutralize any pressure build up and stop fuel from flowing out? It only stops when I put the fuel petcock to the off position.

Can anyone explain to me why gas would continue to flow through the fuel pump and out the exit barb with the bike not running, the gas cap on or off and only stopping when the petcock is in the off position? I am confused to say the least!! Thanks



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Rednaxs60
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Joined: Wed Nov 18, 2015 12:44 pm
Location: Victoria, British Columbia, Canada
Motorcycle: 1985 GL1200 LTD
1995 GL1500 SE CDN Edition
2012 Suzuki DL1000 VStrom
2008 GL1800 (sold)
Ontario 1985 GL1200 LTD (sold)

Re: Free Flowing Fuel question

Post by Rednaxs60 »

I've looked into this and reviewed the owner's manuals for '84 to '87 carb 1200s. Honda details in the owner's manual that the fuel shutoff valve be in the off position whenever the bike is not being used and is not started. I would surmise it is for this very reason. The only exception is the fuel injected '85 and '86 models that only use the fuel shut off valve when working on the fuel system.

Cheers
"When you write the story of your life, don't let anyone else hold the pen"

Ernest

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G-Wiz
Posts: 40
Joined: Wed Jun 15, 2016 11:31 pm
Location: Bellingham, Washington
Motorcycle: 1984 GL1200 Standard

Re: Free Flowing Fuel question

Post by G-Wiz »

I'm no expert on the subject by any means but I believe you have a stuck or sticking float since it only coming from one carb.

superbill
Posts: 13
Joined: Fri May 02, 2014 9:27 am
Location: Maryville, Tennessee
Motorcycle: 1984 Honda Goldwing Interstate

Re: Free Flowing Fuel question

Post by superbill »

Thanks for the replies. As for the stuck float, I checked that and the float is ok.

As for the petcock being put in the off position when it's not running according to the owners manual, here is what I found out. In my owners manual it states.. " The off setting is only for long term storage or servicing of fuel system." It then states this.. " With the fuel valve set to ON, fuel flows to the carburetors only when the engine is being started or is running. A diaphragm of the fuel pump SHUTS OFF FUEL FLOW WHEN THE ENGINE IS TURNED OFF."

So thanks Rednaxs60... you lead me in the right direction and I have my answer.

My next question.... Do I need to replace the fuel pump or can I open it up and replace the diaphragm??



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