HELP! Fuel leak | GTAMotorcycle.com

HELP! Fuel leak

ac.dc

ac.dc

Active member
I have a 1992 Suzuki GSX750R. I purchased the motorbike 3 seasons ago and don't have the service history. Last year after the riding season was over I filled up the fuel tank, changed the oil and removed the battery as is the case every winter. Today being a good sunny day, I decided to take the bike out for a ride, connected the battery, turned on the fuel flow, held choke and gave it a crank – there was a monumental fuel leak from under the bike. I switched off the ignition. Upon inspection I could not find any cut fuel hose. It looks like one of the carburetors is overflown and is leaking fuel. I am not very handy when it comes to carbs and nor does my condo parking give me much space to explore. Is there any one or if you know any mechanic who can help that would be awesome. I am in the Yonge & St Clair area.
 
@frekeyguy is awesome and can pick up bikes. You are in peak season though so you may have trouble getting a mechanic to look at your problem quickly.

It could be a stuck float and it is dumping out the vent. On some bikes you can drop the bowls and wiggle the floats easily (some even have ticklers so you can wiggle the float with the bowls on). I have no idea about that bike.

Vibration from running might be enough to shake it loose but that is obviously playing with fire.
 
Did you fill it up too high? When the tank and full contents warm up in the sun it will expand and exit out the overflow.
 
Does the petcock on that bike have a prime (PRI) setting? If its left in the prime position it'll overflow for sure.
If the petcock only has "on" "off" and "reserve" then it is most likely a stuck float. Try tapping gently on the carburetor bowls with a screwdriver handle.

Sent from my SM-A530W using Tapatalk
 
^ sounds like a stuck or leaking float valve/seat.

leaving a petcock in the "prime" position should not result in leaking; unless there is something else wrong with the carbs involved (such as a stuck float / valve seat problem)

its kind of like a toilet that won't stop "running" unless you shake the handle lol haha
replace the float valve and seat - or free it up if just stuck or hooked..
 
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Ash said:
If you are lucky, tapping on the carb float bowls with the handle of a screwdriver can sometimes free up a stuck float valve.
Click to expand...

Happened to my Hawk when I left it sitting with dry carbs. Fuel was leaking out from between my exhaust header and mid-pipe on first startup. A few taps with a screwdriver handle on the carbs fixed it immediately, and it's been fine for the last 12 years. Since then I stopped draining my carbs for storage.
 
Thank you all for your suggestions. So I tried one of the most common suggestions below which was tapping the all the individual carbs to see if that helps. It sadly did not. I tried to start the bike after taping the fuel still poured out of 2 out of the 4 carbs. Attached are pictures showing the two carbs where the fuel was leaking from.
 

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Ash said:
If you are lucky, tapping on the carb float bowls with the handle of a screwdriver can sometimes free up a stuck float valve.
Click to expand...
Sadly that did not work

Wingboy said:
Did you fill it up too high? When the tank and full contents warm up in the sun it will expand and exit out the overflow.
Click to expand...
It was always stored underground in a condo parking. But I did fill up with a little space left for fumes.
Iceman said:
Does the petcock on that bike have a prime (PRI) setting? If its left in the prime position it'll overflow for sure.
If the petcock only has "on" "off" and "reserve" then it is most likely a stuck float. Try tapping gently on the carburetor bowls with a screwdriver handle.

Sent from my SM-A530W using Tapatalk
Click to expand...
Does not have a prime setting. It has on & off. Looks like a stuck float.
 
If the float is stuck "down", would a quick shot of compressed air up the drain hole help, or would that cause other problems?
 
Relax said:
If the float is stuck "down", would a quick shot of compressed air up the drain hole help, or would that cause other problems?
Click to expand...
I wouldn't do it. For it to be draining, the float should already be mostly submerged. Increasing pressure could make the float slightly more buoyant but it could also collapse the float and then you're screwed (and you wont know you have crushed it).

Maybe something vibrating against the float bowl? Oscillating tool should reach (obviously dont put teeth against the bowl). Other vibrating objects may work as well, use your imagination to find something you have access to.
 
GreyGhost said:
@frekeyguy is awesome and can pick up bikes. You are in peak season though so you may have trouble getting a mechanic to look at your problem quickly.

It could be a stuck float and it is dumping out the vent. On some bikes you can drop the bowls and wiggle the floats easily (some even have ticklers so you can wiggle the float with the bowls on). I have no idea about that bike.

Vibration from running might be enough to shake it loose but that is obviously playing with fire.
Click to expand...
+1

Also try tapping on the carb with a soft mallet (gentle blows)

Parts for those carbs will be harder to find. Hopefully they haven't been taken apart much,
older carb's are generally a nightmare to work on (as they are usually messed with a lot)
 
When people say "tap" they mean give it a good whack with a screwdriver handle. A gentle tap may not be enough to shake it loose.
 
frekeyguy said:
+1

Also try tapping on the carb with a soft mallet (gentle blows)

Parts for those carbs will be harder to find. Hopefully they haven't been taken apart much,
older carb's are generally a nightmare to work on (as they are usually messed with a lot)
Click to expand...
Will try that today
timtune said:
When people say "tap" they mean give it a good whack with a screwdriver handle. A gentle tap may not be enough to shake it loose.
Click to expand...
yeah i figured after the first few taps were gentle :D
 
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