Modern Vespa

Yep, its me again. Firstly, thanks for all the help everyone has given, it's allowed me to stay on the road. I'm finding gas in my oil, but I'm not burning oil. I'm adjusting my valves tomorrow, I'm past due on that. Anyone ever had this "gas in the oil" problem?? Thanks!!

When there is gasoline in motor oil in general, it can be the piston rings that are slow, on an older vehicle, but they can also make many short little paths over and over again can cause petrol to leak.Sorry, sometimes I write in painful English ...

Start with the most obvious which is too much fuel. Either a dribbling injector or a flooding carburettor. Too many short journeys with the cold start device in operation can also lead to this. Over-fueling can also be caused by a clogged air filter or in the case of carburettors with rubber diaphragms small holes that prevent the slide lifting correctly. Normally when the engine is properly warmed up any fuel residue in the oil will be driven off but if the engine does not warm up properly, for example because the thermostat is stuck open, fuel contamination will accumulate.

This was a common problem on the early X9s. If not caught soon enough, it would lead to the plastic oil gear disintegrating...

All down to faulty thermostats and people taking short (<5 mile) journeys. Some people had faulty thermostats and never suffered - as their journeys were always long enough to get the oil hot enough to evaporate the extra fuel.

How do you know if there is gas in the oil?

Sniff the dipstick. Gas/Petrol has a very distinctive smell compared to the engine oil.

Another clue is that the plastic mesh oil screen will become twisted and brittle. This was the usual give-away come service time! In the end my old UK dealer routinely replaced original thermostats in any pre-Evo X9 500 as a precaution. 'Twas not a matter of 'if' but 'when'.

If I am not mistaken, the GT 200 is carbureted? My 2007 LX had the same problem! The fuel tank has a vacuum operated petcock on the fuel tank. If that fails in the open position the needle and seat in the carburetor has to hold back the fuel from gravity feed, hard to do over time and the oil sump cand fill with a fuel and oil mixture. Easy fix if that's what it is! Is the oil full over the full mark? Good luck!

Keenkut is correct. This is probably the main cause of your issue. It happens because if the diaphragm leaks, fuel will gravity flood the carb and run into any open inlet valve, down the cylinder past the piston rings into the sump. Replace the diaphragm and the problem will go away. I'd also change the engine oil.