This may seem like a dumb question but figured I should ask anyways; I have a 50 8n and am seeing a bit of smoke from the oil fill, is this caused by blow by from worn rings or could this be something else?

Thanks

I would suspect there is some blow by but it seems to be common in any old motor. unless your using oil or blowing oil out your breather cap I wouldn't be to concerned about it. my 960 hardly uses any oil at all but I do get some smoke out of my breather cap.

While blow-by is a likely cause (do a compression check) it could also be steam; is the inside of the filler cap milky?

If you do not have a t-stat in the engine, it takes a long time to reach operating temp; on a cold day, it never will and the water in the oil never boils off.

See tip # 25

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Glad to read this post. Makes me feel better about our 640 and it's blow by!! I've read before that it was ok , but we have been working it hard lately and it's nice to be reminded that all is well.

Yep thats blow by, happens to the best of engines, three things in life are guaranteed death taxes and blow by. And the reason you know blow by is inevitable was all engines on older cars had a blow by tube when they left the factory. They left the factory that way because the engine was dommed to a long life of blow by and the crankcase needed a vent so pressure would not build up and blow your seals out. Next was the pcv which ran the blow by back into the engine so it would go out the exhaust. That was done to pacify the hippies cause they wanted cleaner air. Where it goes in todays engines I dont have a clue. Now if its not bad enough that you look like your fogging insects and your just getting some small puffs your ok.Now your puff and my puff is sujective so ----------If your fouling plugs thats when it needs attn. You can run a compression check if you want and that will give you some idea where your at. However I had one that had only 35 lbs and the blow by was only just visible motor started and ran ok. Make sure you oil cap is good and clean and venting as it should because you want to vent the crankcase as I mention before. I was told that I was crazy on my 35 lbs comp test and that the motor would not start much run but it did, better lucky then good I guess.

:)
Good post.
When it comes to engines I think it's better to have blow by than blow up.