Modern Vespa

Only happened a couple of times so far, but I have a feeling I should maybe get in early with this one in case we have an actual problem developing...

This week I decided to take advantage of the good weather and get the scooter out for some proper runnage. The weather here's been almost exclusively rubbish since about the start of August so this week has been the first chance in ages to ride further than the daily commute (exactly 5mi each way). Went out on Thursday and put probably about 50mi on it without any reason to think anything funny was going on.

Yesterday I did about double that, in three main sections. First off I went about 30mi, got off and wandered about for maybe 10-15min and got on my way without incident. Desperate for fuel and in an unfamiliar town (the one I was born in, actually, but unfamiliar nonetheless) I rode around til I found a garage to fill up at. Filled up unusually gingerly for some reason - it turned out to be just as well since the pump didn't automatically shut off and I noticed the fluid almost filling the neck of the tank, just shutting it off with a couple of cm to spare.

Anyway, nothing spilt, no waste and I got on my way again. Rode maybe another 20mi (during which time I passed a couple of classic Vesps - eye candy) without any incident, parked up in a town centre and went for another wee walk in the sunshine for half an hour.

When I got back to the bike this time there was an ominous puddle around the centre stand lever which I noticed was being rapidly topped up by a drip, apparently coming off the underside of the engine. Closer inspection showed it was coming from one of the open ended hoses that points down just in front of the engine. So probably not as bad as I first thought but still more than a bit concerning.

It had to be fuel. Didn't have the viscocity of any sort of lubricant and there aren't any other fluids in there except engine oil, gear oil, and fuel (are there?). So, I decided to see if it would start before I phoned for recovery and it came right to life as normal. I started riding and constantly checked for more drips, of which I saw no sign.

35(ish)mi later I was home and the whole journey had passed without incident. I parked up in the middle of my garden so I could keep and eye out for more puddles appearing but there were none for the rest of the night.

This morning I got out to head for an early start at work, started the bike and wheeled it out on to the street. Turned out I'd forgotted something so I switched it off, headed back to the house and when I got back? Sure enough, another embarassing little puddle next to my pride and joy.

Again, kept an eye out during my journey and it seemed fine. Parked it up at work and headed down this afternoon to check for any signs of recurrence, but nothing.

Obviously I'll need to keep monitoring it and I'll take it to have it checked out if it happens again (twice could be coincidence, three times is a pattern) but in the meantime, does this sound familiar to anyone? Any suggestions as to what might be causing this?

Apologies for the windbag post, but well done and thanks for reading if you've made it this far. All suggestions as to possible causes will be welcomed.

Is it leader or pre-leader? Common places for leaks are round the oil filter and drain plug. These would hit your centrestand. Trace where the hose comes from. One open ended hose comes from the filler neck. Are you absolutely positive it is coming from one of these?

I would guess a bit of fuel got into the vent line, and was expelled as the tank warmed up. I've had similar on several scoots after a 'brimming'. The X9 500 would do it straight away after a fill-up while I waited to pay - the fuel would expand due to the hot bike and start forcing a considerable quantity out of the vent hose.

Thanks for the responses, chaps.

Doug - it is a LEADER model. I can't be 100% sure it's coming out the hose, it looked like it was (since I was panicking at the time - "Ah shoite! Where's that coming from? Oh that hose..."), but thinking about it, I suppose if there was something leaking onto the hose it could give the impression of dripping out of it when it's just dripping along it. Thing I keep coming back to is how intermittent it is: made it home from work today after posting the question without any further signs of leakage.

Jim - that answer was the best-case scenario I was hoping for. I'm wondering if maybe the reason it returned this morning was residue of the original overflow collecting in the pipe as it cooled overnight. Starting it up would maybe have heated/blown/shook that residue out the bottom of the hose.

As I said, I'll keep an eye on it and post back with any developments. Should it happen again I'll make sure and lift out the tub to pinpoint exactly where it's coming from. It didn't even occur to me when it happened that there was more than one hose there!

If the thread stops here any future readers can be assured that Jim's answer was spot on.

LOL Sorry that just really cracks me up