Gas smell in my oil

[Trucker jay]

I just changed the oil in my gti 300 a couple weeks ago and checked it after I got to work.  Oil level was a little high and smells like gas. I was checking seeing if this happen to anybody else.  New oil filters are on order planning to change oil and watch it very close maybe a one time deal if not glad I got a warranty.

[CROSSBOLT]

Based on your other posts, I would guess you got several thousand miles on your DT. I have a little over 6500 miles on mine and I get a little gas smell in mine when the oil is cool like if I wait too long after riding to finally dump the oil. Since mine seems to be running quite well, I don't worry about it. Every other engine seems to do the same thing especially the ones with really high miles. HiFlo Filtro HF566 is a good filter for the DT300i at less than 7 bucks each.

Karl

[ophelia]

How many miles or how many months do you go before an oil change?

[de dee]

   I change the oil between 2500 miles and 3,000 miles, Im up to 24,000 miles so far, and I use mobil 1 full syn.,  as the miles pile up the scooter runs better,   and smoother,.  my baby is 300i downtown  2011,.   went for a ride today the weather was nice , got home and was surprized I went 23  5 km.s  used up most of the winter gas,  last fill up was in Jan.  when I damn near froze  using the nov. gas,  it was 10 below C.  and the roads were clear and dry,

[Trucker jay]

I had 200 miles on that oil.  I got some new filters in and changed the oil again and the gas smell came back so I dropped the scooter off at dealership

[Porkie]

If the scooter had a carb, I'd say the float needle is worn allowing gas to run into the cylinder, down past the rings and into the oil sump, causing the overfill situation and "gas" smell.

If it's fuel injection then the injector could possible be leaking somehow and create the same situation.

Sam:)

[ophelia]

Do you idle the bike for a long time when you start it?

[Trucker jay]

No long idle, longest I idle is abt 3 minutes then let it for a couple of minutes before checking the oil

[boo]

Please let us know how this plays out.

[Trucker jay]

I got it back from the dealer they said it showed no codes and that my air filter and oil was dirty and needed changing.  I got my scooter back home air filter on order.  I have at the most 15 miles on the oil and filter but I'm going to change it out.  I'm letting it set a week and pulling the spark plug out and using a long gun cleaning swap check for fuel on top of piston.  Might also use a wood dowel to record fuel level.  Anymore trouble and I'm talking it to a nearby scooter only shop.

[Porkie]

A dirty air filter can cause a very rich situation that allows much more fuel into the intake tract where some of it gets past the combustion process and then runs past the rings into the crankcase, The piston, rings and cylinder can be ruined quickly it this happens. The automotive term for this is "washdown."

A bike/ scoot with fuel injection should just cut down on the fuel to match the air available but a carb'd bike/ scoot will not cut back the fuel so the mixture is very rich. Constant velocity carbs are better in this situation than 'slide' type carbs.

Sam:)

[MotoRandy123]

My Aprilia Scarabeo 500 had fuel smell in the oil too. I tried to find the problem
but then just assumed it was normal and rode it like that.

I think the design lets a bit of blowby into the crankcase....

[Trucker jay]

I know over filling can cause starting issues but can that be my problem, can fuel vapor mix in the oil like that?

[zombie]

Porkie is spot on but the maf sensor in a fuel injected engine will prevent that issue..
 Trucker... Do you have a vacuum/emissions schematic for the scoot or can you find one to post up?

There may be an issue with a fuel vent loop into the crankcase.
OR you may have a bad injector that is dripping fuel from the line when the scoot sits. Do you have any coughing when you first start?
No other rough running issues?

Your idea of swabbing the cylinder is a good one. I am curious as to what you find.
Also may I suggest a compression test. Maybe blow by from high miles or dirty oil or bad break in habits.