4th drive of my new engine

[rotayt]

just wanna see why the oil in my engine has very small bubles on the oil on dipstick when i check it, im guessing as it is new???

[Sterling]

You need a PCV valve. (Positive Crank Ventilation)
This is where the crank case is vented to a vacuum sourced part of the intake. This will suck out all the water vapor from your crank oil.
As your crank oil cools down, it creates condensation. Spring like structures inside the oil contract around water molecules, protecting the steel components.
When the oil heats up, the spring structures within the oil expand, releasing the water, which promptly vaporizes and rises out of the crank oil. It tries to go out the filler tube, but if there is no vent to allow it to escape (or vacuum it out), when the engine cools down again (after shut down) some of the water collects along with a bit of vaporized oil in an emulsification on the insides of the oil filler spout. It often looks like white goop after a while, and is commonly refered to as "lung mustard".

[orion84gsl]

One thing to add. If that moisture is allowed to sit in the filler tube it will cause rust to form in the filler tube and it can the chip off and fall into the oil, which would then do serious damage to the insides of the engine.

[Sterling]

-rust chips can either scratch up moving parts, or get lodged in the oil journals inside the eccentric shaft. Either way, it spells probable premature wear, and possible catastrophic failure.

[rotayt]

ok thanks for that it helps very much!!! i will get on to it as soon as posibble!!!

[Kentetsu]

There are a lot of writeups on how to add the PCV valve to the system.  I simply run a vacuum line from the nipple on the filler tube to the base of the carb.  Seems to do the same thing, and I haven't had any issues since.

[orion84gsl]

^ Same here and I haven't seen any moisture buildup in my filler tube since installing it.