White Smoke/Vapour From Crankcase Breather

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snydes
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White Smoke/Vapour From Crankcase Breather

Postby snydes » Tue May 23, 2017 7:00 pm

Got this steady white/grey smoke/vapour coming from my crankcase breather tube (Hose pointing out above chain guard since no air box and easy place to fasten) which occurs once the bike is warmed up. I can't seem to find any really 'good' definitions of what this could be. I rebuild this bike back in 2015 (gaskets, valve clearances and lapping, ton of carb work and then general essential items) and once i finally started riding it in 2016 i noticed the same smoke i'm referring to now, but I don't think it was as bad. People have said it could be condensation and to go for a long ride and it will probably go away but i have never had it go away even after long rides. Some have also said it could be excessive crankcase pressure but I don't understand how I would get that other than over filling which I have not done to my knowledge (will double check).

I am running 20W50 oil since it seems to be burning oil a good amount when running 10W40, run K&N Oil and Pod Air Filters, Carbs jetted, aftermarket exhaust system. 1989 FZR400 1WG with 73,000kms.

Also how often should valve clearances be checked? After doing them in 2015 i have ridden about 8000km and not rechecked them but am most likely going to do pistons and rings this year (since they have now suddenly become available) and will have to check them then.
Thanks,

ASnyder

Evilchicken0
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Re: White Smoke/Vapour From Crankcase Breather

Postby Evilchicken0 » Thu May 25, 2017 7:34 am

It could just be oil mist, y'know just one of those things.
You've checked under the oil filler for water scum ?
You've checked the radiator filler for oil scum ?
The bike hasn't seized since you rebuilt it ....

Old bike innit, if it runs ok then happy days
Don't read everything you believe
FZR400RR 3TJ Bimota SB6

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snydes
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Re: White Smoke/Vapour From Crankcase Breather

Postby snydes » Thu May 25, 2017 11:32 am

It could be but it has gotten pretty steady at some points, I'll get a video of it once this rainy weather goes away. And for oil filler you mean on the clutch side the actual fill hole and then the rad fill you mean just mean right at the front below the tank cover?
And nope it hasn't seized that I know of lol.
Local mechanic was saying it could be blowby or just something that these bikes do since I don't have an airbox and it's not routed to the normal position.
Thanks,

ASnyder

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Re: White Smoke/Vapour From Crankcase Breather

Postby Evilchicken0 » Fri May 26, 2017 10:51 am

Yes and Yes ... I agree with the mechanic. If this went into an airbox it would go though the carbs / engine / pipe and away
Don't read everything you believe
FZR400RR 3TJ Bimota SB6


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