Fuel coming out of exhaust

[DadsWing'76]

Hey all!! I've been working on a 1976 GL1000 that used to belong to my father, but after he passed, it became part of my family. I had gone through and cleaned the carbs, and the fuel pump, new plugs, checked the timing(statically). Then I decided to give it a crank. She fired up and ran for a good hour....a little rough at times, but she kept chugging away.
Fast forward few weeks to yesterday.....
I fired the bike up and it ran exceptionally rough then would die. I'd start it up again, and it would run for a minute, then slowly idle down and die. I always had to have the choke out to geet the bike to start these times as well. After about 8-10 starts, the bike wouldn't turn over any more. Thinking that I burnt out the solenoid or the starter itself, I left it for the night. I went back at it the next night. I figured I'd pull the plugs and see if it would turn over with the plugs out. When I hit the start button, about a tablespoon of gas came shooting out of clyinder #1, the rest were good. I decided to do check the valve clearances, and only cylinder was out by a hair. I put the plugs back in and decided to give it another go. So choke out, I hit the start button. What happened next, I have never encountered before. As the bike was turning over, I noticed raw gas literally running out of BOTH my exhaust pipes. I have the muffler clamps loosened off where they connect to the headers as I removed the back tire. So I have gas running out where the clamps are. I THINK I know what is happening, but could use a little expertise here. I believe that a carb float on either side if the engine (possibly all 4 floats) is stuck, allowing gas to flow freely up and into the cylinder and then flooding out the engine and eventually going out the exhaust valves and out to the pipe and onto the floor. I am also guessing that this has likely caused gas to invade the nice clean oil I just put in the bike days ago. As I never replaced any of the parts in the carb, the needle and seat sealed well when I tested them, just blowing lightly through a piece of tubing connected to the fuel inlet. I'm thinking they are still good, but feel that there a re a couple floats stuck. What do you guys think?

One other question regarding the fuel pump. I still have the mechanical one installed. When the carb floats shut off, the fuel pump would still be pumping correct? Is there a pressure bypass on the pump or how does that work so as no to put too much fuel pressure into the carb bowl and possibly 'force' fuel past the needle jet? OR is the fuel demand enough that this isn't ever a problem?
Sorry for the long winded story here, but I fell that more info is sometimes better to have a good understanding of what I have happening.
Thanks in advance for any info!! :thanks:
Jason in Edson, AB, Canada

 

[desertrefugee]

You need to resolve that right away. If you get too much fluid/gas in the cylinders you could hydrolock the engine and do serious damage. Carbs are needy.

 

[pidjones]

With the rack off, rig up a fuel supply at leasr 1.5 meter higher than the rack and test them (I use isopropyl alcohol to cause less problems) and they should have zero leaks. There are many special U-rings and a plenum seal that really must be replaced when you break down a rack. The brass can just be cleaned and returned to service but with new o-rings. You might also need to rebuild your petcock. If you haven't replaced fuel lines and inline filter, attend to that also. Any left-over fuel in the tank should be flushed out and the tank interior inspected for rust or trash in the bottom.

Altough the float valves can be reused, make sure their rubber tips are clean without ridges. Check, check, and recheck float levels. The pump will not overcome the float valves if the valves are in good shape.

A sniff of an oil sample will tell you if it is contaminated if you do it before your nose gets gasoline ladden.

 

[mcgovern61]

I had just cleaned my 1100 carbs over the winter. They sat for a few months before I installed them and had a similar problem with raw gas leaking. Pulled the rack and recleaned the needle tips. I turn them gently on 3000 grit sandpaper to get them smooth.

Rack up on a small chair, refilled with gas (although I like the alcohol idea!) and gravity feed from a lawn mower tank. While filled, I turn them quickly to 45 degrees in every direction simulating riding hard into corners to be sure they do not leak.

 

[dan filipi]

Definitely make sure you always turn the petcock to OFF when parked. Hydro lock has bent many a rods in this motor.

 

[joedrum]

Wow good advice so far ..the most important is turn gas off after try to run it ...as explain in words I'd say there multiple things going on ..full choke indicates possible air leak ..maybe at the intake boots
.if bike sat a long time im sure the boots ate dry out and possibly not sealing after removal and put back. And you said floats sticking also witch can be other things in those parts ..like float vale springs weak ...the carbs ate a mess of parts that bearely capable to do the job ..thete also 50 yrs old ..the slides are metal on your yr carbs and need to move freely the needles are just thete and can stick also ..fuel will not come out of both exhaust from one carb .
So problem is multiple and on both sides of motor ..as for idle it has nothing to do with carb sync and all comes from the idle Circuit after the throttle plate towards the motor ..if bike sat a long time it probably has some compression issues that only gets better from running it ..this all sounds huge I know but I'm just spelling out issues on motors that have set forever ..having plugs out spinning motor and using ATF or some cleaner may get rings working better ..intake boots should be drowned in ATF for a few days ..while you go though carbs again ..ATF IS cheap mericle fluid for all carb parts ..it tough battle to reverse it's been sitting forever condition ..you have to go big in battle LOL good luck

 

[saganaga]

pidjones » August 20th, 2020, 4:46 am[/url]":17s0afde]
With the rack off, rig up a fuel supply at leasr 1.5 meter higher than the rack and test them (I use isopropyl alcohol to cause less problems) and they should have zero leaks. There are many special U-rings and a plenum seal that really must be replaced when you break down a rack. The brass can just be cleaned and returned to service but with new o-rings. You might also need to rebuild your petcock. If you haven't replaced fuel lines and inline filter, attend to that also. Any left-over fuel in the tank should be flushed out and the tank interior inspected for rust or trash in the bottom.

This is good advice. For.testing, I leave the assembled rack hooked up to fuel overnight and put something underneath that will be discolored if gas leaks. Usually something around the garage - just find some paper product, test by putting a drop of gas on it and letting it evapoate. If it leaves a mark, you are good.

 

[DadsWing'76]

Some great advice and tip from you all, so THANK YOU VERY MUCH!!
SO ...... just a little update.
I pulled the carbs, very carefully, in order to not bump them around , incase a float was stuck open. I rinse out an windshield washer fluid jug and rigged it up as a makeshift fuel tank. Set it up about 10' above the carbs and ran tubing down to it. Left it sit for two days, and nothing. I put some absorbent pads that, when they get wet, they go dark. After two days, they were still dry. So I pulled the top slide off of the #3 carb and found the slide was kind of sticking in the cap, it did come out, but I had to wiggle it a bit not sure if this would have caused a scenario like this, but that's all I found so far. So at this point, I have contacted someone at Randakks as to when they will have their carb master kits back in stock, as I want to get one on the way to me. Start there with the rebuild and the see what happens. I'm at a bit of a loss ...... I was sure hoping to see something to indicate an issue.

 

[julimike54]

opcorn:

 

[desertrefugee]

Sticky slides will definitely not create the condition you are describing. More than likely you have or had some debris and one of the needle seats. Or a stuck float. Plenum seal or carb to plenum seals would still be leaking if they had been the culprit. So it was something transient. Or not.

Regardless, an overhaul using quality soft parts is never a bad idea.

 

[DadsWing'76]

Ya.... I didn't think a slide would cause that either. Carbs are still hooked up to the makeshift fuel tank, and still no leaks. Just pulling at straws right now, nut will end up pulling apart again and checking things all out when I get my kit from Randakks, complete the rebuild and go from there.
Will keep you updated as to anything I find. Once again, thank you for all the suggestions.

 

[Magonsterz!]

DadsWing'76 » 2020-08-19- 20:04[/url]":34k2iks6]
Hey all!! I've been working on a 1976 GL1000 that used to belong to my father, but after he passed, it became part of my family. I had gone through and cleaned the carbs, and the fuel pump, new plugs, checked the timing(statically). Then I decided to give it a crank. She fired up and ran for a good hour....a little rough at times, but she kept chugging away.
Fast forward few weeks to yesterday.....
I fired the bike up and it ran exceptionally rough then would die. I'd start it up again, and it would run for a minute, then slowly idle down and die. I always had to have the choke out to geet the bike to start these times as well. After about 8-10 starts, the bike wouldn't turn over any more. Thinking that I burnt out the solenoid or the starter itself, I left it for the night. I went back at it the next night. I figured I'd pull the plugs and see if it would turn over with the plugs out. When I hit the start button, about a tablespoon of gas came shooting out of clyinder #1, the rest were good. I decided to do check the valve clearances, and only cylinder was out by a hair. I put the plugs back in and decided to give it another go. So choke out, I hit the start button. What happened next, I have never encountered before. As the bike was turning over, I noticed raw gas literally running out of BOTH my exhaust pipes. I have the muffler clamps loosened off where they connect to the headers as I removed the back tire. So I have gas running out where the clamps are. I THINK I know what is happening, but could use a little expertise here. I believe that a carb float on either side if the engine (possibly all 4 floats) is stuck, allowing gas to flow freely up and into the cylinder and then flooding out the engine and eventually going out the exhaust valves and out to the pipe and onto the floor. I am also guessing that this has likely caused gas to invade the nice clean oil I just put in the bike days ago. As I never replaced any of the parts in the carb, the needle and seat sealed well when I tested them, just blowing lightly through a piece of tubing connected to the fuel inlet. I'm thinking they are still good, but feel that there a re a couple floats stuck. What do you guys think?

One other question regarding the fuel pump. I still have the mechanical one installed. When the carb floats shut off, the fuel pump would still be pumping correct? Is there a pressure bypass on the pump or how does that work so as no to put too much fuel pressure into the carb bowl and possibly 'force' fuel past the needle jet? OR is the fuel demand enough that this isn't ever a problem?
Sorry for the long winded story here, but I fell that more info is sometimes better to have a good understanding of what I have happening.
Thanks in advance for any info!! :thanks:
Jason in Edson, AB, Canada

had fuel running out of my exhaust (headers off) , tried to light off to make sure it was firing. Pulled carbs off, filled with mix of Berrymans, fuel and carb cleaner over night, the flipped over to confirm floats were traveling, repeated one more night, drained, assembled, ran like crap till warmed up. Shut down, let cool, with fuel off restarted, let run till started to lean out, opened up fuel, it came up to temps and runs like a charm. Maybe debris but most def rear right float issue as could visually see fuel running in from there as viewed from the top prior to. Dumb luck as was fiddling around while waiting on carb kits to show that now are extra on hand should i ever need. Synced set up couple days ago and havent had an issue since. best of luck to ya.

 

[joedrum]

Great news