1988 1100F, gas leak when running only

[HBUS1300]

Went out to ride to work this morning, moved the bike out of the garage and started it to let it warm up. Came back and there was a small puddle of gas in the kickstand region under the bike. Quickly hit the cutoff and decided it was a good day to drive after all.

I've had this bike since May and haven't had any carb issues, bike runs great. Just went for a 100 mile ride 2 days ago with no issues.

My first thought was a float was stuck, but I didn't have time to diagnose the problem further as I had to get to work. Turns out traffic was awful, so it sort of worked out.

Other than a stuck float what else can cause this sort of issue? Again it's only when its running. I guess I can turn the petcock to prime and see if gas runs out, because it should just flow at that point. That would tell me if it's the float (i think?)

I know that some will say pull'em off and clean/rebuild 'em, but i'd like to try and avoid that if possible as i've got a lot of other stuff going on.

Thanks.

[Norwingsx]

the fuel line is closed until the vaccum from engine open it. this maybe the reason off leaking only when run. check the fuel line / hose before you get carbs off.
pull the vaccum hose off the petcock and suck it with another pice of hose. it wil show you the leak if the problem is between petcock and carbs

my english is bad. I know

[crazycraven420]

the fuel line is closed until the vaccum from engine open it. this maybe the reason off leaking only when run. check the fuel line / hose before you get carbs off.
pull the vaccum hose off the petcock and suck it with another pice of hose. it wil show you the leak if the problem is between petcock and carbs

my english is bad. I know

your english is better than some Americans

[HBUS1300]

Thanks Norwingsx, Thats a good point about pulling the vacuum hose off the petcock. I'll use my mityvac and draw some vacuum on it and that will let me see where the fuel starts leaking from. Maybe it's just a bad piece of fuel line, being 24 years old that's a distinct possibility. I'll be sure to update this thread with what I find the problem to be and the solution. Thanks again.

the fuel line is closed until the vaccum from engine open it. this maybe the reason off leaking only when run. check the fuel line / hose before you get carbs off.
pull the vaccum hose off the petcock and suck it with another pice of hose. it wil show you the leak if the problem is between petcock and carbs

my english is bad. I know

[Stumpy]

If your fuel lines are 24 years old - then yup, probably time to replace them

I don't know anything about the 1100's, but it can't cost that much for a couple of feet of line and some fresh clips

[muddblood]

Thanks Norwingsx, Thats a good point about pulling the vacuum hose off the petcock. I'll use my mityvac and draw some vacuum on it and that will let me see where the fuel starts leaking from. Maybe it's just a bad piece of fuel line, being 24 years old that's a distinct possibility. I'll be sure to update this thread with what I find the problem to be and the solution. Thanks again.

No update??

[crazycraven420]

I'll use my mityvac and draw some vacuum on it and that will let me see where the fuel starts leaking from.

you dont need much draw on the vacuum line, you can literally just suck on it. Not sure how much pressure your mityvac would apply to it but it would suck for you to damage the diaphragm in the petcock.

[Wild-Bill]

If you're still running the original fuel lines then they're your most likely culprit.
2 ft of 7mm fuel line should have you fixed right up.

[HBUS1300]

Thats a good point about too much vacuum. I was just looking to use the thing for something other than brakes. I'm sure it will be apparent where the leak is by the amount of gas that leaked out earlier. I didn't get a chance to work on it today, but will definitely be diving into this tomorrow. Thanks everyone for the assistance and advice.

you dont need much draw on the vacuum line, you can literally just suck on it. Not sure how much pressure your mityvac would apply to it but it would suck for you to damage the diaphragm in the petcock.

[HBUS1300]

Turns out I got lucky and its just fuel lines. The line was split where it connected to the petcock causing it to leak profusely. Just glad this happened in the driveway and before I was riding with a hot engine waiting to turn into a ball of flames. Looks like i'm going to stop by the local shop and see if I can get some fuel line and some clamps, as there are currently no clamp on either petcock connection. Clamps might not be necessary, but the idea of a line working it's way off isn't reassuring, I'd rather deal with the clamps than have fuel spraying if a line pops off.

Thanks everyone for the help.

[Stumpy]

I just use the same type clamps you find at the airbox plug etc. Simple, effective, and dirt cheap