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Fuel in the oil :(. (solved)

Discussion in 'Technical and Troubleshooting Torque' at netrider.net.au started by Netterhead1, Nov 5, 2008.

  1. Read my last post


  2. The prime position bypasses the vacuum system, so it must be the vacuum that has the problem. As you have already proved that sucking on the pipe opens the tap, try looking to see if the connection from the inlet manifold to the pipe has a blockage.
  3. i cant see a blockage between the manifold and the vacuum pipe.

    bike doesnt even start up properly now...

    i wish i knew more about engines. i think im gonna take it to a shop see if they can do anything.
  4. got it running today by taking the air filter out.
    i then took the airbox off the carbs.

    The engine started readily and idled much better.

    the breather hose from the rocker cover had a large amount of white smoke coming out of it. i wish i took video.

    i put my finger on the end of the breather hose and pressure built up in the hose rapidly. the stream of smoke was constant, not pulsing.

    there was liquid petrol dripping from the breather hose and the smoke smelt strongly of petrol.

    just so you know what i mean by breather hose, i have an old photo of the engine attached.

    I believe this indicates a large amount of petrol dissolved in the oil. im waiting for the engine to cool and i will drop the oil out and have a smell.

    If anybody has experienced this before please reply and tell me what you know.


    P.s the fuel tap seems to be working since i clamped the vacuum tube on to the fuel tap.
  5. I dropped the oil out yesterday and it reaked of petrol. So definatly lots of fuel in the oil.

    One of the float needles has sht itself and is bouncing on the spring eg the spring in the needle isn't as firm as the others. I beleive the needle wouldn't be seating properly.

    I've ordered in some needles from the US as I couldn't find them here in. And I'm not gonna go down the needle and seat assembly line(one assembly costs more than 4 new needles incl shipping)

    I beleive the failure of the needle has caused the cylinder to flood and fuel has seeped past the piston rings as a result causing the petrol in the oil.

    What else could cause fuel in the oil to a great extent?
  6. I think you're spot on with the float needle diagnosis and hopefully that will fix it.

    It may be worth checking the tap all the same. I've found in the past that fuel can bypass a porous diaphragm, run down the vacuum hose and into the manifold/ port area. A tankful can drain into the engine in 24hrs.

    Given that you've had a vac problem with the tap, it's well worth checking.
  7. Sounds like the carbs have reached the end of their service life,and it might sound drastic but trading the bike on something newer is probably a better option that going down the never ending repairs road.

    What's next, bottom end bearings from fuel diluting the oil?
  8. Yes it's the float needle causing the poor running, but if you are getting fuel in the oil when the bike is off you also have a dicky tap.

    Pull it apart and clean it.
  9. I had this exact problem i dismatled the fuel tap and stretched the spring so it seals harder. It hasnt happened since, touch wood.
  10. ok i havent posted in a couple of days,

    on wednesday i put new oil in and new oil filter on the bike. started up fine. smelling alright. i decided to take it for a ride to see how it was.

    i got from Berowra to Killarny , roughly 30-35 kms when the bike decided to suffocate itself again. its a very distictive bruuur. this was as i was coming up the hill from the roseville bridge. its a steep long climb that cars whiz past at 80kms no shoulder. :roll: i managed to bump the bike up onto the gutter with my last 5 kmh of momentum.

    i pulled the tank off, had a smell around and there was a strong smell of petrol still in the airbox but the breathe hose had a mild smell in comparison to what it was on monday. i decided to ride home with the breather hose disconnected and the air filter out. it ran like a charm with no air filter.

    anyway. i rode to work on thursday breather disconnected all sounding good.

    last night i put a new air filter in, reconnected the breather hose. did some other misc work on the bike and today had an awesome time out at oran park on a stay upright course.

    next i need to install new needles and clean all the jets thoroughly.

    all in all, bikes running great. thanks for your help all.