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Home Forums Bikes BMW F650 "The Coffee Machine"

This topic contains 8 replies, has 4 voices, and was last updated by  Nick Massey 2 years, 10 months ago.

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  • #8763

    Expat
    Participant
    • Location:
    • Bike:
    • Rank: 50cc Rider

    Hi All I have an old F650 with 146K on the clock which currently has the nickname ‘The Coffee Machine” because of the oil it dribbles whenever I stop. It used to be a lot worse untill I took it for a service and pointed out the issue to the mechanic. He put in a baffle to slow the back flow (or some other mod which i didn’t really understand) and it seem to have reduced the coffee stain but not cured it completely.

    Does anyone else put there have the same problem, know what causes it, or most importantly how to fix it? I am embarrassed to park it on the pavement and tend to let the oil run really low before topping it up – not good practice I’m sure but nor is staining the roads and pavement or indeed grass, gravel and riverbeds!

    Sorry if this is a bit off-topic for adventure rides, but I can’t seem to find a solution elsewhere and know there are other F650 riders in here somewhere.

    #8765

    Eddieb
    Keymaster
    • Location: Hamilton
    • Bike: Suzuki DR650 ADV
    • Rank: 1200cc Rider

    Hi @expat

    Great post and the perfect area to post it in. Do you have any pics that show the leak and where abouts it’s coming from?

    Putting a baffle or something in the oil system that restricts the oil flow around the motor from the original design doesn’t sounds like a great idea to me, but then I’m not a mechanic.

    #8773

    Expat
    Participant
    • Location:
    • Bike:
    • Rank: 50cc Rider

    I don’t have any pictures of the leak, but believe it is coming from the air filter box under the seat (over the exhaust). Apparently with the F650 the oil tank is in the frame yet part of the ‘flow system’ is through the air cleaner box…. All a bit odd if you ask me but it has drain tubes which support this idea.

    The baffle was installed to “slow the flow of oil, whilst still allowing the engine to breathe”. I’m actually wondering whether the air cleaner box is warped or cracked – given it sits over the exhaust – it does seem to have some kind of heat shield but maybe after 19 years and 146,000 Kms, it’s beginning to fail.

    The air box itself is a complete pain to remove and my inspection of it was ‘inconclusive’ – rather than do it all again, I was hoping some one here might either confirm they had the same issue, and it was the air box, or that I’m barking up the wrong tree and should be looking somewherfe else….

    #8781

    Barry
    Participant
    • Location:
    • Bike:
    • Rank: 50cc Rider

    Hi Expat, Removing the airbox is nearly as bad as removing & reassembling the headlight & associated bits. I am sure ze designers at ze reichstaag BMW have special sessions on wacky baccy to find new & creative ways of pissing off those who want to DIY by making it easy to dismantle & then a pain in the arse to put together. The 2 pins that hold the plastic piece under the screen are an example of this. Try & change a headlight bulb without wrecking the plastic fitting ring while everything is still in place. Damm the things that happen when ya aint got a gun.
    The 00 model F650 has a tube from the airbox with a bung in the end, maybe for the same reason. It comes out from the rhs bottom of the air box near where the intake bits screw on, so a solution may be to drill a hole at the lowest point of the air box with a fitting to slip a hose with a bung on it if there is not one already.
    There is a problem with oil flinging off the chain by the front sprocket etc & dripping into the bottom engine guard & then dripping down the centre stand when parked in the garage.
    It may also have contributed to a recent major oooops by dripping onto the side of the rear tyre & getting onto the tread when parked using the side stand. Will be cleaning the chain & changing to chain wax to see if there is an improvement & no increase in chain/sprocket wear before fitting a loobman that can use chainsaw bar oil which is supposed to be super resistant to oil flinging off.

    #8785

    Nick Massey
    Participant
    • Location: Pukerua Bay
    • Bike: 1999 CBR600F (Hornet), 1989 NC30 VFR400, 1998 BMW F650ST
    • Rank: 50cc Rider

    I have a F650 and while it doesnt leak…yet that sounds like the general area of the overflow tube. There should be 2 there one for Petrol and one for oil.

    #8786

    Nick Massey
    Participant
    • Location: Pukerua Bay
    • Bike: 1999 CBR600F (Hornet), 1989 NC30 VFR400, 1998 BMW F650ST
    • Rank: 50cc Rider

    The crankase breather will vent into the airbox but it means the more pressure you get on the vent pipe the worse your engine is. As they are the leakage gasses that go past your piston rings or valve guides. And yes as Wilbur mentioned when the oil level is too high you will also get more oil coming out of the vent.
    We used to have a pressure leakage tester ( not a compressiontester) and we used this to put airpressure through the sparkplug hole to the top of the piston placed at TDC valves closed. When you measure the amount of air that leaks past the rings or valves you know what part has failed.
    If it is the exhaust valve it would blow out a lighter kept in front of the exhaust
    If it was the intakevalve it would blow out of the carb when you open the throttle. If you slightly unscrewed of the oil filler cap the cap would blow almost out of your hands if it was the pistonrings or valve guides.
    And if you kept your hand in front of the vent pipe you knew that if you had pressure there that it meant an engine strip.

    A must BookMark to have for any F650 owner

    http://www.f650.co.uk/forums/showthread.php?6834-Oil-leaking-from-airbox

    #8790

    Nick Massey
    Participant
    • Location: Pukerua Bay
    • Bike: 1999 CBR600F (Hornet), 1989 NC30 VFR400, 1998 BMW F650ST
    • Rank: 50cc Rider

    Here is a manual, its in Spanish but its still very useful, I have the English version somewhere around here.

    https://mega.co.nz/#!91QEFYIR!KcvwDJwanWKgLscnrnlOxer8q1bhm1lspVlWX4YxoqQ

    #8865

    Expat
    Participant
    • Location:
    • Bike:
    • Rank: 50cc Rider

    Hi All

    Thanks for all your help – I’ll have it checked out by someone who knows what they’re doing. My last mech did admit he hadn’t seen many F650s in his career.

    I don’t think it’s rings – There’s no smoke. Maybe I’ve over-filled it, but then it’d stop once it’s leaked enough…it hasn’t stopped yet. Guess that means valves – Are they expensive? Given it’s only a $2k bike, I really don’t want to spend heaps on her – as much I love her 🙂

    #8867

    Nick Massey
    Participant
    • Location: Pukerua Bay
    • Bike: 1999 CBR600F (Hornet), 1989 NC30 VFR400, 1998 BMW F650ST
    • Rank: 50cc Rider

    <cite>@expat said:</cite>
    Hi All

    Thanks for all your help – I’ll have it checked out by someone who knows what they’re doing. My last mech did admit he hadn’t seen many F650s in his career.

    I don’t think it’s rings – There’s no smoke. Maybe I’ve over-filled it, but then it’d stop once it’s leaked enough…it hasn’t stopped yet. Guess that means valves – Are they expensive? Given it’s only a $2k bike, I really don’t want to spend heaps on her – as much I love her 🙂

    lol I love mine to, I hope to never have to get rid of it…….BUT if it came down to an expensive repair I would have to let it go.

    get it to someone who knows the bike, maybe a dealer but dont let them talk you in to some idiotic crazy inspection bill.

    where are you if you dont mind me asking, if you are in the welly area I can point you in the right direction

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