Modern Vespa

The GT has been sitting for about a week due to the temp drop, and was running fine before I parked it. It usually cranks up immediately, but yesterday I had to open the throttle all the way and crank the crap out of it to get it started, and then it would not stay running unless I worked the throttle, so after about two miles I turned around and parked it in the garage. Today, I decided to investigate and drained 60cc of oil/gas mix out of the rear airfilter drain. After I drained it, it started right up and is acting normally. I thought I smelled gas in the oil, but the fumes were so heavy I can't be sure. I'm going to drain and replace the oil on Saturday just to be safe. This issue happened once before, but that was with the evap system connected.

Now, the evap system was completely removed two years ago and I haven't had issues like this since then. What should I look for now?

Thanks!

You may want to consider disconnecting from the roll over valve to the canister to prevent build up of vacuum in fuel tank causing diffculty in starting and stalling. This can be manually remedied by opening up fuel cap to relieve pressure.

The below [[ ]] was an edited posting and I can't remember who.

But read carefully, it covers disconnecting in two places:

1. Fuel collar to roll over valve (this should be disconnected), would recommend disconnecting after the roll over valve so you still have an effective means to prevent fuel leak should a roll over occur.

2. Carburator (I believe you took care of this)

See diagram.

[[I have disconnected four of these on Piaggio products and several on BMW motorcycles over the past eight years.

You can actually leave all the evap equipment on the scooter as long as:

1) You cut the overflow line going to the canister from the gas tank. Then, just add an extension to the line and run it towards the ground for any overflow from the top of the tank when you fill up.
2) Cut the hose that goes into the carb (or throttle body in fuel injected engines) and put a small filter where you cut it before it goes into the carb. (in a fuel injected engine, plug the hole of the hose before it goes into the throttle body with a bolt or plug and clamp it so the plug can't fall out)
That's it. Everything else is just sitting there doing nothing so you can remove it or leave it. If you leave it, you can quickly hook it up in case your state ever passed an inspection law for emissions equipment compliance. (not likely but anything is possible with politicians looking for revenue).]]

Good Winter Project...good luck!

Like I said--I removed the entire evap system two years ago. Removed. Gone. Plugged the appropriate holes in the carb. Gone. Ran an overflow line down the frame. It works fine. I tested it by overfilling, and it flows properly to the ground. That's why this puzzles me.

Could someone have knocked it over? Sounds like a classic bike on it's side.

Nah, she was in the garage. Only thing unusual was I didn't ride her for a several days due to it being cold and drizzly. After I pulled out all the evap crap a few years ago she has been absolutely reliable. I pulled every bit of it out after an incident like this. Still have all of it in a box on the shelf.

Weird. Classic tip over results. Did you change the oil yet? Make sure the area doesn't smell like gas so you can get a true smell. If the oil doesn't smell like gas run it and see if it does it again. Good luck and if you can, tell us you find.

My GT200 requires a bit of a throttle thrust while starting from a cold engine. What you got out of the airfilter is not common. Check your engine oil level after this calamity please and report back to us. Maybe someone here can help some more. Overflow in the airfilter compartment is usually due to the wrong kind of oil or overfilling the crankcase. Keep us posted. Thanks.

you may want to check your vacuum controled fuel valve had mine fail in open position runing gas to carb all the time,easy check remove fuel line at carb not running if fuel flows valve is open & can flood engine & air filter.
hope this helps.

Now there's me thinking that on carb'd bikes the carb hole shouldn't be plugged, though it should be on the FI models...

But as above, very possibly a stuck-on fuel tap.

I'm going to take a look at that after work tomorrow. I know I replaced it once, but it bears looking at again.

what's the latest findings on your gt200?

took me a while to get to it. Seems ok for now. Will keep watching it though.

Well during the last cold spell it did it again, this time filling the crankcase with gas. It is the petcock.

Dealer says the ethanol eats the rubber inside these vacuum petcocks and the cold made the tearing worse and hence the leak.

This petcock lasted two years. As long as we keep burning corn, the petcock on the GT has to be considered a short term wear item apparently.

Can't you find any ethanol free pumps where you live? We have about 5 on the island and i haven't put ethanol gas in my scooter in a very long while. I think it runs better but that might just be wishful thinking.

Not anymore, and it's well over an hour to the nearest marina. Too much trouble to haul a can to the airport, give an "N" number and get a few gallons. I'll buy a second petcock and keep it in the garage. Will just change our every other winter, I guess.