Fuel venting?

[Sparky]

My dealer said it wasn't a problem, but I just wanted to check here.

We've been going through some fairly wide temperature swings of late. It can be 5C in the early morning and 15C in the afternoons. I had also just filled up. I tend to go almost but not quite to the lip of the fuel spout when filling up. Probably a little bit high but not too bad.

Riding home today, I took a slightly different route. One that put me on an expressway for a couple minutes in the far right lane. Basically, it took me from an on ramp through a tunnel into an off ramp. It also required me to gun it to 80km/h. As I'm only at 100km (or 150, based on the distance not recorded on my odo last week), I may have heated up the engine a bit. This on top of some stop and go during the commute. I also hit a bump, not nearly is bad as the one that bent the rim on Saturday. Still, paranoid. I parked the scooter on the sidewalk to get a look at the oil level and check the back wheel.

I found a fluid dripping from beneath the right hand side, beside the seat, down onto the dipstick cover. Since I knew the Metro 125 is air-cooled, my immediate thought was "cracked gas tank!". The dripping continued for thirty seconds, there was a sudden spurt that left a loonie sized gas-stain on the concrete, then it tapered off. I don't think there was more than a shot glass worth of gas leakage. Checking under the cap revealed the tank is pretty much full. There hasn't been any leaking since, after checking twice this evening.

Some vague mechanical memories and a call to my dealer indicated that it was the carb or fuel system venting. Does this sound correct, given the brief nature of the gas dribbles and the location?

[illnoise]

My dealer said it wasn't a problem, but I just wanted to check here.

We've been going through some fairly wide temperature swings of late. It can be 5C in the early morning and 15C in the afternoons. I had also just filled up. I tend to go almost but not quite to the lip of the fuel spout when filling up. Probably a little bit high but not too bad.

Riding home today, I took a slightly different route. One that put me on an expressway for a couple minutes in the far right lane. Basically, it took me from an on ramp through a tunnel into an off ramp. It also required me to gun it to 80km/h. As I'm only at 100km (or 150, based on the distance not recorded on my odo last week), I may have heated up the engine a bit. This on top of some stop and go during the commute. I also hit a bump, not nearly is bad as the one that bent the rim on Saturday. Still, paranoid. I parked the scooter on the sidewalk to get a look at the oil level and check the back wheel.

I found a fluid dripping from beneath the right hand side, beside the seat, down onto the dipstick cover. Since I knew the Metro 125 is air-cooled, my immediate thought was "cracked gas tank!". The dripping continued for thirty seconds, there was a sudden spurt that left a loonie sized gas-stain on the concrete, then it tapered off. I don't think there was more than a shot glass worth of gas leakage. Checking under the cap revealed the tank is pretty much full. There hasn't been any leaking since, after checking twice this evening.

Some vague mechanical memories and a call to my dealer indicated that it was the carb or fuel system venting. Does this sound correct, given the brief nature of the gas dribbles and the location?

Yes.

[Sparky]

Yes.

I *do* go on, don't I?

Same thing happened today. No leakage in the cool morning, but it happened parking after coming home through a lot of stop and go traffic during a 19C afternoon. I ducked under and found the source: a small canister-like thing with a tiny outlet port, connected to a small hose that snaked under the gas tank. Huh. Learn something new every day.

So, quick question. When will this stop? These days gas is expensive enough that even a scooter rider worries about a few drops. Worth their weight in gold!

[illnoise]

Yes.

I *do* go on, don't I? :D

I've definitely wasted hundreds of words asking a yes/no question before, ha.

I don't know the Buddy that well, so you might want a second opinion, but if you overfill, it very commonly leaks out the overflow gizmo, and if you've only taken a couple short trips since, you're probably still just sploshing gas into the overflow.

There are other causes for gas leaks of course, so if it continues when the tank is half empty, you'd definitely want to get it checked out.

Bb.

[Sparky]

I visited the dealer today to have my license plate installed. As is common, the plate needed to be drilled to fit the Taiwanese-style bracket. Anywho, the underseat bucket was taken off to have a look-see at the engine. Apparently the dripping farkle is the evaporative-system filter. It happens to be on the right side...the side that Kermit landed on after the lowside on Saturday.

His guess? The fuel in the tank sloshed into the evap hose and filter, soaking the latter with gas. The stuff that is coming out is the excess fuel from the mishap; once it is gone, the dripping will stop. This fits with the nature of the leak. It only happens when it is hot--enough to heat the gas-soaked filter enough to make the fuel escape. So, no main fuel line or tank leak.

[Kraut]

Most vehicles, two or four wheels, now have to conform with EPA and CARB. Therefore they are, next to many other emission lowering devices, equipped with charcoal canister. This canister will absorb fuel fumes from the tank/carb when the vehicle is parked to avoid them releasing into the atmosphere. During operation of the engine the canister is cleaned or "purged' by sucking the fumes from the canister back into the carb. and burn it.
Now, if you overfill the fuel tank, raw fuel can enter the vent line to the canister and cause saturation as well as leakeage to the outside. Also, right now there is a transition from winter to summer fuel. Winter fuel has a lower boiling point. So, if your bike is exposed to high temps during the day, this will also fill up the canister. Normally no big deal since the fuel will be recycled through the carb. However, fuel can detoriate the charcoal and damage the canister and cause debris to enter the carb or injection system. Sometimes this will cause running issues as will as plugged lines. How do I know? Worked for a major German bike manufacturer and encountered this issue before, especially during the transition from winter to summer.
What's the best cure: Don't fill the tank up all the way; leave a bit space...or go for a long rider after refueling. Also good for meditation!
Another solution could be to remove the charcoal canister and hook up a nitrous bottle with remote push button instead. Now please don't ask me for instructions....EPA or DOT might look at this forum

[Pita1963]

My dealer said it wasn't a problem, but I just wanted to check here.

We've been going through some fairly wide temperature swings of late. It can be 5C in the early morning and 15C in the afternoons. I had also just filled up. I tend to go almost but not quite to the lip of the fuel spout when filling up. Probably a little bit high but not too bad.

Riding home today, I took a slightly different route. One that put me on an expressway for a couple minutes in the far right lane. Basically, it took me from an on ramp through a tunnel into an off ramp. It also required me to gun it to 80km/h. As I'm only at 100km (or 150, based on the distance not recorded on my odo last week), I may have heated up the engine a bit. This on top of some stop and go during the commute. I also hit a bump, not nearly is bad as the one that bent the rim on Saturday. Still, paranoid. I parked the scooter on the sidewalk to get a look at the oil level and check the back wheel.

I found a fluid dripping from beneath the right hand side, beside the seat, down onto the dipstick cover. Since I knew the Metro 125 is air-cooled, my immediate thought was "cracked gas tank!". The dripping continued for thirty seconds, there was a sudden spurt that left a loonie sized gas-stain on the concrete, then it tapered off. I don't think there was more than a shot glass worth of gas leakage. Checking under the cap revealed the tank is pretty much full. There hasn't been any leaking since, after checking twice this evening.

Some vague mechanical memories and a call to my dealer indicated that it was the carb or fuel system venting. Does this sound correct, given the brief nature of the gas dribbles and the location?

I had the same thing happen to me yesterday, the second day of my Buddy ownership. I freaked out and after a call to Sportique was told the same thing, over-filled the tank, blah, blah blah....

Kinda weird though.

Robb

[tatoepfer]

Oh thank god I found this thread. I just had this happen - someone pointed it out at the grocery store and said "hey lady, your scooter has a gas leak"...I was flipping out.

So now do I wait for this so called Vapor Lock to happen?