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Crf 450 r 05

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shoudnt smoke atol mate my guess is the oils getting up ny the rings causing it to burn and also get into carb , new piston and rings is needed , people are a nightmare these days when sellings bikes everyone seems to have a rebuild 5 to 10 hours ago but without an hour meter its hard to tell . honda states in the manuel piston change every 30hrs . ive done 20 on my 2014 since rebuild stull like new might put another 20 - 40 hours onit

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There is another possibility on how you can get oil in the carburetor:  thru the crankcase vent circuit

 

In typical Honda fashion the vent exits the rocker arm cover then goes into a plastic T fitting, 

the bottom tube has a plastic plug, excess oil (vapor turned liquid) accumulates in there but can't drain out.

 

The top tube goes to the airbox and is under constant engine vacuum, by design helping the engine's dry sump 

oiling system function but also able to suck in oil from the bottom tube if it fills up to the T fitting.

Remove the air filter and located the aluminium 'suction' tube in the airboot, is the tip super oily?

 

If the bike has been inverted a few time and/or suffers from a lot of blow by (worn piston & ring)

the more it's likely to fill up that bottom tube with oil. I take a habit of checking / emptying it at each oil change.

Edited by mlatour
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First off, oil can get into the carb on ANY 4t by using a lot of engine braking.  When the throttle is closed and the intake valve opens the combustion chamber pulls a vacuum and it needs to be filled.  "Some" air will leak through the carb even with the throttle closed but it will also pull some air from the crankcase, and that air is laden with oil.  Normally it's a very very small amount of air/oil, but it's there.  Then when the throttle is opened some of that air/oil mix will burp back through the carb.  That's mostly how oil gets into the carb and air filter of a 4t engine.  New engine rebuilds or older engines with worn rings will get more oil past the rings and into the carb / air filter.

This doesn't explain how the water got mixed with the oil in your carb.  Check to see if the crankcase oil has water in it, if it does then fix that and both problems should be fixed.

If not then we need to figure out where the water came from, is it possible that you've been riding through some deep water or have been somehow getting your air filter wet when you wash the bike off after a ride?  Or you maybe even have some water in your gas...

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