Does prime setting = fuel leaking always?

[Sci85]

Ok, I test fired my GS550M yesterday using an old lawn mower gas tank for a fuel cell. Obviously this setup has no vacuum controlled fuel flow and althought he bike ran, I had a drip from somewhere within the fuel bank. I couldn't tell for sure where as it seemed to be running along the front carb rail.

Anyway, will running a setup that uses pure gravity feed fuel delivery, say like running off the "prime" setting, always result in gas leaking from the carbs? Shouldn't the floats shut the fuel flow off once the bowls are full?

Thanks.

[Agemax]

you should not get any leaks as long as everything is set correctly. try and trace where the leak is coming from. could be a bad hose joint or the float heights stuck or set incorrectly

[tom203]

First ? = nope
Second ? = Yep, floats with good fuel needle seats should hold fuel back for a while

[GateKeeper]

no isues using the gravity feed way, and no leaks I could detect....

[sedelen]

There has been a long standing argument about this.
Most of the owners manuals have a caution about leaving the bike in "Prime" as the carbs could overflow. Does that mean it will leak? Possibly.
Yes the carb float shut off valve should shut off the fuel once the bowl is full.
I have two bikes and have left them in Prime by forgetting not to turn them to the on or Reserve position and yes they both leaked gas. I have tried to be very careful about not leaving them in Prime again. But just recently I did, but this time no leak? Only thing I can think of that was different was bike was on centerstand where previous times sidestand. Perhaps the angle the carbs were sitting while on the sidestand had something to do with it.
If the engine isn't running you'd probably be better off just to disconnect your make shift fuel tank.

[Sci85]

Cool. Thanks for all the input. That's what I figured but this is the first bike I've had with this kind of petcock setup. I will begin looking for the source of the leak. It's probably the fule line itself. There's no clamp on the carb side of it. Unfortunately, that means pulling the rack out

[Agemax]

you dont need to pull the rack off to get to the fuel line

[MisterCinders]

you dont need to pull the rack off to get to the fuel line

True, but reconnecting a fuel line to that T is maddeningly difficult with the rack on the bike.

[tkent02]

True, but reconnecting a fuel line to that T is maddeningly difficult with the rack on the bike.

You're doing it wrong.

[MisterCinders]

You're doing it wrong.

By putting the fuel line onto the T before installing the carb rack?

If there's a cool trick for putting the line onto the T with the carb rack in place, I am all ears.

[Agemax]

it is so simple, get one hand in underneath to stop the T from turning, push the pipe on with the other hand.
you do need the tank off and OK........i have fairly thin hands, i suppose if you have big hands and fat sausage fingers then i guess it could prove tricky

[tkent02]

I saw a posting once...I never got to do it myself but.

You use a stiff wire. You push it through the fuel line then into the T fitting, Then you push the fuel line on, turning and pushing.

DP

I have done this using a welding rod, anything skinny enough and stiff enough would work. A little lube helps too.

[Sci85]

Neat trick! I may give it a try just because its so dang aggravating dealing with the rack. But first I need to figure out if that is indeed the source which is kinda tricky in and of itself with the carbs installed.

[clancey g]

i had old 8mm fuel line with clamps leaking on the rack, there was 1 spot a long screw driver can just reach into to undo clamp on the rail, but i could not see it while i did it, i did this worked a treat with correct size fuel line, no clamps needed scroll down the post. oh and i've got 2 meters spare 7mm fuel line if any one around bris is in need of some

http://www.thegsresources.com/_forum/showthread.php?t=190206

[duaneage]

I have done this using a welding rod, anything skinny enough and stiff enough would work. A little lube helps too.

Taken out of context, this would be a very naughty post.


The fuel level in the carbs is high enough that if the bike is on the sidestand fuel could make it out of the vents if the bike leans far enough. Also, leaving the fuel on prime will cause fuel loss since gasoline evaporates from the carbs and will slowly replace through the PRI setting. Might not seem like much but over a few weeks it adds up.