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1971 engine : a lot of white smoke from exhaust and breather pipe

Discussion in 'Norton Commando Motorcycles (Classic)' started by pierodn, May 20, 2018.

  1. pierodn

    pierodn

    Joined:
    Nov 10, 2012
    The engine had 5000 km from new.
    Yesterday after 60 km. done from the right exhaust and the breater oil tank (this hose goes not in the air filter but fre accross the rear fender under to the the licenze plate) it started out a lot of white smoke.
    What do you think is happened?.
    For a complete information the bike had new oil red Castrol 25/50 and new oil filter and mounts the Jim Comstock sump filter breather.
    Thank you.
    Ciao
    Piero
     
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  2. Fast Eddie

    Fast Eddie VIP MEMBER

    Joined:
    Oct 4, 2013
    Condensation from inside the engine and emulsified in the oil?

    See if it goes away with more KM before panicking too much...
     
  3. Dances with Shrapnel

    Dances with Shrapnel VIP MEMBER

    Joined:
    Jul 8, 2011
    Check plug on RH cylinder for oil foul. Consider a compression check. Sounds like some serious blow by.
     
  4. pierodn

    pierodn

    Joined:
    Nov 10, 2012
    Hi.
    What means "condensation from inside the engine and emulsified in the oil?".
    In case why?
    Thank you.
    Piero
     
  5. pierodn

    pierodn

    Joined:
    Nov 10, 2012
    Hi.
    What means "blow by"?.
    Thank you.
    Piero
     
  6. pierodn

    pierodn

    Joined:
    Nov 10, 2012
    Hi.
    What means "blow by"?.
    Thank you.
    Piero
     
  7. kommando

    kommando

    Joined:
    May 7, 2005
    Blowby, combustion chamber air forcing past the rings and going into the crankcase. Could also come past the guides into the Rockerbox.
     
  8. Fast Eddie

    Fast Eddie VIP MEMBER

    Joined:
    Oct 4, 2013
    Condensation is “water which collects as droplets on a cold surface when humid air is in contact with it”.

    So, humid air and a cold engine left to stood for a length of time could well result in condensation inside the engine.

    Emulsified means the water is mixed thoroughly into the oil (by the oil pump etc).

    My thinking is that the vapour created when the oil is heated might show as ‘white smoke’ in the tank vent pipe when the emulsified oil returns to the tank and the hot / vaporised water separates from the oil.

    From my recollection, when talking about exhaust smoke: oil smoke is blue, rich mixture smoke is black, and white smoke is from ‘burning’ water. Hence my thought.

    But, ‘tis just a thought.

    Do please let us know what you eventually discover.
     
  9. pierodn

    pierodn

    Joined:
    Nov 10, 2012
    Water!!
    Why the engine makes wather?.
    Please let me understand better.
    Thank you.
    Piero
     
  10. o0norton0o

    o0norton0o

    Joined:
    Apr 27, 2015
    the "water" comes from the humidity in the atmosphere inside the crankcase,... BUT after an engine heats up, all the water that has condensed inside the engine is boiled off and exits the crankcase via the breather on the engine into the oil tank. Then, once the engine oil is hot, the water in the oil tank is vaporized and exits out the oil tank breather hose.

    If you have white smoke coming out of the tail pipe, then your problem isn't water vapor. More likely it's a valve guide leak, an intake valve seal is bad, or your piston rings/bore is allowing oil to leak past them.
     
  11. Bodger

    Bodger VIP MEMBER

    Joined:
    May 9, 2017
    Piero, I am assuming this is just a translation issue. Here is an example in, hopefully simple, English. Condensation: when you take a hot shower on a cold day the water that is on the bathroom mirror is condensation. Another example would be the outside of a chilled glass of Prosecco on a humid day. So, for example, if you keep your bike in a cool garage and then take it outside on a hot, humid day, you can get condensation (water) inside the engine just like you get it on the mirror in the bathroom. More commonly condensation gets created in the engine when temperature and humidity changes occur relatively quickly in an enclosed garage. If you don't run your bike up to full operating temperature some of the condensation (water) can partially separate from the oil (emulsify) and look like traces of mayonnaise on the inside of your oil tank near the cap or even get blown out of whatever kind of breather you have. For some reason 650cc Triumphs do this pretty often and it is common to see it trapped in the "D" cross section breather hose on the rear fender.
     
  12. htown16

    htown16 VIP MEMBER

    Joined:
    Apr 29, 2009
    Condensation won't cause white smoke out the mufflers. Just one cylinder or both? Does your bike have a cross over pipe between the exhaust header pipes? If it's just one side may be little rubber seal on the intake valve has split. Apparently it can be repaired with out pulling the head.
     
    Kvinnhering likes this.
  13. htown16

    htown16 VIP MEMBER

    Joined:
    Apr 29, 2009
    What bike are we talking about. You have the same question on Triples on Line. So is it a Trident, Commando or both?
     
  14. pierodn

    pierodn

    Joined:
    Nov 10, 2012
    Hi.
    Both bikes, commando and R3.
    Same problems.
    Commando only right silencer, R3 both.
    Piero
     
    Last edited: May 20, 2018
  15. htown16

    htown16 VIP MEMBER

    Joined:
    Apr 29, 2009
    I'm having a hard time getting my head around this. How can two different bikes simultaneously develop the same symptoms. It's got to be something they have in common, gas, environment, ?
     
    Last edited: May 20, 2018
  16. franko

    franko VIP MEMBER

    Joined:
    Dec 29, 2013
    Were the bikes started and not ridden a distance when the weather was cold?
     
  17. pierodn

    pierodn

    Joined:
    Nov 10, 2012
    Same trip both bikes.
    Warm weather.
    Ciao
    Piero
     
  18. Fast Eddie

    Fast Eddie VIP MEMBER

    Joined:
    Oct 4, 2013
    I still say it sounds like condensation in the engine and oil.

    Take them for a good long run, get them properly hot. I’ll bet this ‘problem’ just goes away.
     
  19. Fast Eddie

    Fast Eddie VIP MEMBER

    Joined:
    Oct 4, 2013
    Continuing with the ‘white smoke = water’ hypothesis...

    Is your fuel high in ethanol?

    Ethonal is hygroscopic, meaning it absorbs water out of the atmosphere. If it’s been in the bikes a while, perhaps it could be a contributory factor.
     
  20. pierodn

    pierodn

    Joined:
    Nov 10, 2012
    We dont have ethanol fuel in Italy.
    Ciao.
    Piero
     

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