Modern Vespa

Drippage off the gearbox for a while now, have been collecting it in a pan, it looks like Motul 2 stroke oil, there's quite a bit of oil puddling off the back of the engine coming down from the rubber plug at the back of the airbox.

I took the airbox cover off and noticed fuel puddling at the back of the airbox. Must be that the gasoline mostly evaporates, leaving only the Motul to drip off the gearbox onto the garage floor.

Does this mean I need a carburetor rebuild?

pretty normal bud

...yep

Check to see if the screw where the fuel line connects to the carb is tight or wet for that matter. You could nip it up an 1/8 or 1/4 of a turn. Being aware that too much could strip the thread (ie half a turn)

That sorted mine

looks like the grommet at the base of the carb box around the fuel line has had the dick





if you take off the spark plug lead and air filter then kick it over you'll see fuel n oil spits out the top of the carb

also crank that hose clip tight too

That's too much...look for a fuel leak. There should be a washer under the screw where the fuel line attaches and under the banjo. Also, make sure the float bowl washer is doing its job...

unna



could be the float has a hole in it too

So this is while parked overnight? Do you turn off your fuel tap?
If you have a dead float or a leaky float valve it might look like this. Or most any other slow leak from the carb.

First thing I'd try is tightening up this clamp, as mentioned above. Area looks wet.

I'd look at the float, the small gasket on the banjo and small stuff 1st.. don't go rebuilding your carburetor quite yet.. and while you're at it.. replace that fuel line with some Goodyear line and don't put a clamp on it..

There are some very good suggestions so far, but if i may press my point...

IMHO id still recommend moving the bike forward 1/2 a foot wipe the underside and then crank that hose clip and ensure the fuel line screw is fully home 1st. Check it the next day for puddles, before replacing hoses or checking float bowls. But thats just the easy way out.

If the most basic tightening does nothing and youve already taken the fuel line off "for a look" (ruining the sealing properties of the mentioned washers) , then spend the 9 bucks and buy a carb rebuild kit and go through the inspect and replace motions as suggested.

Also consider replacing the fuel float needle (very cheap) as these can also wear and flood your carb, giving float bowl puncture symptoms.

Based on my own observations from my 2 stroke P series scooters, I believe that most of the oil residual comes from the rotary pad spitting back some oil/fuel mixture during normal operation. That ends up hitting the carburator air filter and eventually cloging it.

I have two P series with auto oil injection and they both leave me a puddle of oil. It is just the nature of the beast, I think is normal.

really? How unfortunate. ive 2 px's and neither of them leak puddles on the floor of the garage

edit- in saying that there is truth to that, if a cloggged filter allowed the spit back into the carb box it has to go somewhere

I had a problem with a poorly made gasket that caused the air box to fill up with oil.
Partially blocking the transfer hole.

Grumpy

Is it just oil thats there, no gas?

Thanks for all your replies. In thinking about the nature of the leaked fluid further, since it seems to contain oil AND gas (though most of the gas is gone by the time it drips onto the garage floor) doesn't it make sense that the leak is occurring AFTER the oil becomes mixed with the gas? If that's the case, then I must have a leaky gasket in the carb somewhere, or maybe at the base of the carb, right? Altogether, it doesn't seem especially normal, or safe. I even found a little fuel puddling in the air intake hose. Time for a rebuild?

A bad seal between the carb and carb box can result in oil seepage into the carb box. Could be the gasket. Could be warped carb base. Start by checking those two. Such oil puddles pick up blown back fuel, and thus a fuel smell. Or, could have a slight fuel leak into the oil puddle.

i had my carb top off today and have the same issue.
mine appears to be leaking out front too as the engine is wet w/ oil/gas behind and in front of the carb. (could that be a carb base gasket bad?)

it leaks like crazy out of the plug. i have to degrease and spray it often as it leads to clumpy sand/dirt collecting on everything.

i also noticed some oil collecting on top of the air filter... thought that was weird.

i shut off the tap after running it every time (occasionally forget) and i just replaced the float and needle with a new one.

I must agree with Vader here. Putting a clamp on the fuel line will just cause it to fail prematurely. Install a proper fuel hose , do not clamp it and I'll betcha that will solve the problem. Good luck

+1
- new fuel line that is the non see threw type
- felt gasket washer that seals the bolt that holds on the fuel line IN top hat thingy

there is another felt washer under the float bowl top hat bolt also and around the lip of the top hat

all these need to be in good condition or fuel can drip and accumulate

When I still had a p-200 I ran the carb box without that rubber plug (mixture access hole) since I would gather have the puddle of gas exit carb box and not cause a overly rich mixture that can foul plugs.

these rides drip no matter what

get used to it

I went to O'Reillys Auto Parts and bought a sheet of thickish paper gasket material ($6 Line item FEL Number 3046--more gasket material than I'll ever need in my lifetime), pulled the carb (intact) off, traced the pattern of then cut out the base gasket; put it all back together, made a test run, no more leak.

The leakage was oil and gas, so it kinda makes sense. The only defect in the carb box that could bleed out oil-gas is a leaking base gasket or a warped carb. Nice call Aviator47.

^^^ Good deal man! I make most of my own gaskets too.. the stuff I get is Grey but similar.. I think they work better! may just be in my head, but they never leak! I hope you stay leak free!

I was going to say base gasket but im glad you got to it. but dude get some real fuel line, not that clear, evap hose. if you want to make sure the fuel is getting to the carb (as most would suggest is the best reason to use "clear" fuel line) just pull off the banjo and turn on the tap. besides, the real stuff lasts a shit ton longer. good job.

by "top hat" do you mean the part that the fuel filter is in? or are you refering to the banjo the fuel line is attached to?
i have alot of gas around the top of that.
there is a little red washer under the bolt that holds the cap on where the fuel filter resides.

yup

those felt washers are key
and any others that seal the fuel where it needs to be kept at

those clear fuel lines get splits under the hose clamps all the time due to getting brittle w/ age and ethanol fuels used...

may look fine but are not = replace it

Why not clear? There is plenty of good see through fuel line. Motion Pro baby. Or if you wipe with $20's get some fancy BGM anti-kink fuel line. And I like the Kinks. An no for the record I do not have the BGM stuff on my bikes...

I also like clear because you can visually check flow.

Next...

I replaced all the gaskets except the base and those when I tried getting it to stop leaking before. The kit didnt have em in it. I changed the fuel line w marine grade line as I had it left over from my boat.
I'll have to find the base and felt gaskets.
Thanks fellas.

Thankyou, I was gonna mention this too. I don't know the brands, but while most clear plastic lines are crap, I have three old ones still in use that I wish I knew where they came from. Motion Pro, eh?

Flow shmo.

The black stuff is awesome cause you put it on and forget it. No stoopid clamps. No pulling panels and looking at your fuel line.

you funny jimmyb

always use hose clamps
they are cheap and helps eliminate leaks around IN's and OUT's w/ fuel

A good proper hose with the proper ID will not require clamps.

But by all means.....clamp as you wish.