Strong gas smell from 86 VFR700f

She kicked my ride, outside! She said the smell was hell.
Lose the smell of gas, or it's your ass.

So, my 1986 VFR700F sits in the driveway.

Tonight I removed the tank, and fuel reserve valve and air cleaner and
could find no evidence of any leak.

You guys got any other ideas where the smell comes from? It seems to
me it is the carbs but I cannot be certain.

By the way, the fuel valve looks fine but fails to cut off fuel to the
engine when shut off... What's up with that?

 

Yes, carbs are a likely culprit. Maybe it's the vent in the cap... probably a long shot on that one.

 

Could be a stuck float in one of the carbs

 

A few more words please

If it was a stuck float, it would be down, right? That would allow fuel to flow somewhere... Where would it go? The combustion chamber?
Would it still flow without the fuel pump operating?

I was also thinking that the fuel shut off could be the culprit. I am going to replace the o-rings on that and see if that works.

 

Carb leaks ... fuel odor ...

Hello:

I just pulled my carbs the other day for the first time, and they are sitting on my workbench. That gave me an opportunity to see things on them I'd never seen before.

Therefore, armed with an unobstructed view of the carbs, I’d suggest it could be one of two things (or, maybe both).

First, each carb bowl / chamber (wherein the floats are located) is sealed with a rubber gasket. So, one of those gaskets could be leaking or maybe the bowl / chamber cover simply needs to be tightened. You’d definitely have to pull the carbs to do that, no small task.

Second, each carb bowl / chamber has a drain on it. (Easy to identify.) Simply turning a screw adjacent to the drain opens the valve, and drains the bowls / chambers. So, one of those could simply need to be tightened. That is to say, fuel may be leaking out of the chamber drain(s). With the carbs in the bike, they may not be all that easy to reach. Two are accessible from the right, two from the left.

Gray Market

 

I think you are spot on

Last week I removed and inspected my carbs. Nothing obvious, but it ran fine after re-installation... but then the same thing happened the next day... dripping gas and smell..

I ordered new gaskets for the float bowls and new float needles. We will do a bottom end rebuild and re-install with new rubber boots to the intakes.

That and a new fuel petcock valve should solve my stinky problem. At almost $4.50 a gallon, every drop must be saved....

 

Hmmmm ...

Hello:

Gee wiz, with all this apart there simply MUST be a way to locate / identify the source of the leaks.

When I see these issues on these discussion groups, I always ask myself, "What would I do?"

So, if it were me, I'd put cardboard or some absorbant paper here and there, and see where the gas drips onto the paper. Some process such as that should narrow-down the source.

Also, you mentioned that the fuel shut-off valve on the tank is not working; that it does not shut-off the fuel. If it were me, I'd begin to suspect that. Right now, I just can't think of anything else.

When you figure this out, don't leave us "hanging." Let us know what you figured out, okay?

Gray Market

 

Is your petcock a vacuum operated petcock or just a simple free flowing type??

Cause, if your fuel shutoff is a vacuum operated one, then the fuel will not flow unless the engine is running.

If your fuel will still continue to flow when the bike is off and it's a vacuum operated type valve, your carbs will overflow and the gas will make it's way into the combustion chambers, and then your crank case.

Gas in the crank case will allow fumes from the crank case breather to vent.
Which is what your probably smelling.

This has happened to me once, and it took me forever to figure out....until my oil change came around

Best of luck to you

 

An odd possibilty, but I have an 87 700 and I have noticed a gas smell from mine. I can tell that the sending unit that tells the fuel light to come on is leaking just a touch of gas. not enough to drip anywhere but enough to create an odor. I have not yet replaced as they are a bit hard to find, but you may give that a look. It is on the bottom of the tank near the seat.

 

When the wife says "the smell was like He??", I'm thinking its not a dainty or an annoying odor.

I wish I had my manuals, cause then I could tell you if your fuel shutoff is vacuumed operated or not....

 

luckily, a vfr has a fairly simple fuel system. its basically tank -> filter -> pump -> carbs. mine was leaking fuel pretty bad and stinking up my whole house from just sitting in the garage leaking (tho in the end, i found it leaked like a half tank!). no sooner had i removed the tail section that i noticed the leak coming from the fuel line coming from the gas tank leaking where it clamped to the fuel filter. thankfully, it was a bad clamp job that only cost me 4 inches of fuel line.

bottom line, check every inch of that fuel system starting at the gas tank and ending at the carbs. if you have to use baby powder to locate the source of the moisture, dont be afraid to. vfr carbs are notoriously tricky, and a royal PITA to get off the bike and work on, and even worse to get back on the bike correctly. if that bike's leaking fuel, a watchful eye should be able to locate the leak if you just cover the whole thing carefully.