gas getting into oil?

Discussion in '4-Stroke Engines' started by iwasgandhi, Dec 6, 2012.

  1. iwasgandhi

    iwasgandhi New Member

    Gas seems to be getting into the oil of my 4-stroke. I'm financially broke, so I'm worried it's a bad sign,... :icon_cry:

    I'm hoping that it can either be ignored, or that it's a simple, inexpensive fix for someone who's not an engine mechanic,...:dunce:

    More details :detective: ,... I have a Staton-inc axle-mounted kit with a Robin-Subaru 35cc. I change the oil and filters regularly, and I use the recommended 87 octane. But gas seems to be getting into the oil somehow. I noticed this yesterday for the first time when I changed the oil as I regularly do. The color of the used oil was brown-ish instead of the usual black-ish, and it smelled strongly of gas. As it's a 4-stroke, I don't mix gas with oil. So I'm wondering: is my engine is dying? Or is this normal? Can I just ignore it?

    I eek by on meager fixed income and I can't afford a car. My motor-bicycle is not merely my grocery-getter, it's my access to support groups and a wider social scene. Public transportation is not a viable option.

    More context :thinking: ,... the engine was new approx. 15 months ago, all the gas in my area has 10% ethanol, I've been riding it approx. 50-75 miles per week, and I haven't used any fuel additive to treat the ethanol.

    Could the 10% ethanol be the problem? If so, is it too late to start using a fuel treatment additive? Or does it signify something deadly and darker for my "little-engine-that-could-but-soon-will-no-longer-be-able-to" kind of a thing? :poop:

    Awaiting suggestions :idea: in Rochester, NH

  2. Silvaire

    Silvaire Member

    If fuel is getting into the oil I wouldn't ignore it. It will dilute the oil which will cause engine damage.

    The first thing I would do is make sure that the air cleaner is clean, and that you have not accidentally been running with the choke on - either fully or partially. Either of these will cause an overly rich mixture that will contaminate the oil with fuel. If you suspect that either of these is the case, clean the air filter, change the oil, and keep a close eye on the oil condition.

    If you still are getting fuel in the oil after that, I would then suggest having the carburetor gone through and installing the FULL Walbro Carburetor Kit - part K20-WYL for the carb on your Subaru EH035. If you can do the rebuild yourself, the price of the kit is only around the $10 range. Fuel related issues are common with these little diaphragm carburetors - especially with the fuel we are stuck with having to use. I usually suggest getting only the gasket kit when you have issues with them, but if fuel is leaking into the engine from the carburetor, it is likely from the needle and seat. I am pretty sure that the full carb kit contains both of these parts.
    Last edited: Dec 6, 2012
  3. Old Bob

    Old Bob Member

    60 weeeks @ 75 miles/wk= worn out

    Do a cylinder leak down test with the piston parked @TDC before wasting any money on it.
    The bore in the EHO will have a bell mouth at tdc with that kind of hours.If it passes then look at the carb.
  4. Greybeard

    Greybeard Member

    Are you using the stock fuel tank, and is the carb sitting level?
  5. iwasgandhi

    iwasgandhi New Member

    Thanks for the info, details emerge,...

    Thank you everyone for the helpful and specific info & suggestions. :bowdown:
    However, only after posting my original message did I remember that I had recently replaced the throttle cable (prior to discovering gas in the used). During the cable reinstall I fiddled quite a bit with the small, spring-loaded, rotating thing (don't know the term) on the engine (near the carb) to which one end of the throttle cable is attached.

    Could I have inadvertently flooded the engine with gas when it wasn't running, thus causing gas to somehow get into the oil due to an excess of gas in the system? I'm only guessing. I hope that that was the source of the problem because then it means I can simply keep a closer eye on the oil level and change the oil more frequently in order to make sure that no more gas is getting into the oil. Sound plausible? Hope so. Please let me know,...

  6. Old Bob

    Old Bob Member

    No, the throttle could be wide open with the engine off and not let gas in. If the carburetor was leaking internaly it would drain the the tank and run so disgustingly rich it would foul the spark plug, pull the plug and see what color it is.

    If its rust brown your in good shape as far as mixture goes, if its black then the carb needs a rebuild, if its black and shiny you have other issues.