Okay I have this question about the Head Breather Bypass. I know it is supposed to allow the throttle body to breathe cleaner and some even say it keeps the engine cleaner.
My brother and I both have 2001 Indian Scouts from Gilroy. Mine had 7000 miles and my brothers had 24000 miles. Both of these Bikes from the factory had the Head Breather system directed to the atmosphere pointing down under the frame.
Well my brothers bike had a lot of vibration to it and was running rough. So I tore the engine down and split the cases. Found some problems, but my point is this. With the Breather system it has, the pistons were covered with the black carbon. They have the Super E Carbs if not mistaken. I am sure there will be some carbon build up, but does the Head Breather system really keep the pistons free of excess carbon on the new EFI Carbs? DK Customs shows pictures of the pistons after 8000 miles with a lot of Carbon on them. Which looked about the same as my brothers Pistons.
So does it really?????

Thanks for the patience in reading this. Any opinions are welcome.

Tom

 

Venting crankcase to atmosphere eliminates the oil mist that would be re-ingested into the engine and cause carbon to build up on the pistons and valves.

An engine can also get carbon from a rich carburetor or abnormal oil usage even if it is vented to atmosphere.