2 Small Carb Question

[Scout Sport Fish]

1) What are some adjustments I could possible make to squeeze some extra RPM/HP outta the engine?

2) Also me and my cousin swung a engine today on a go-cart and theres this about 3/8 steel tube that runs from what looks like the bottom of the cylinder wall to the air intake on the carb. What in the world is that for? My only guess was a primitive turbo kit where the piston would compress the air behind it and slam it into the air intake. But Im proablly wrong.

 

[QuadManiac]

Re: 2 Small Carb Question

2 - Sounds like PCV (Positive Crankcase Ventilation) to me. And what does "swung" mean?

 

[rwise]

Re: 2 Small Carb Question

SSF need more info

 

[Scout Sport Fish]

Re: 2 Small Carb Question

Swung-just swapped an old engine for a newer more powerful engine. So whats the advantage of the PCV? Because the hole the the carb were it leads into it sealed of because it was sitting for a couple of years.

 

[QuadManiac]

Re: 2 Small Carb Question

Just dumps gases that blow by the piston rings back into the carb to reburn, smog reduction, basically.

 

[QuadManiac]

Re: 2 Small Carb Question

Even lawn mowers are coming under the jurisdiction of the "pollution police" patrols now.

 

[ZmOz]

Re: 2 Small Carb Question

The PCV's have been there for decades...long before the EPA started sicking their nose where it doesn't belong. If you want your engine to perform correctly, you need to make sure it's hooked up and unblocked. The air that goes in needs to be filtered, otherwise your oil will be full of dirt.

 

[QuadManiac]

Re: 2 Small Carb Question

And decades, precisely is WHEN they started sticking their noses in... remember the advent of exhaust air pumps? 1972 or 73.

Engines used to have a cap on the valve cover filled with steel wool to filter the air both being sucked into and sometimes pushed out of the cranckase for ventilation. This was deemed as a polluter, so they were required to feed this back to the carburetor in the late 60's.

 

[ZmOz]

Re: 2 Small Carb Question

And decades, precisely is WHEN they started sticking their noses in... remember the advent of exhaust air pumps? 1972 or 73.

Engines used to have a cap on the valve cover filled with steel wool to filter the air both being sucked into and sometimes pushed out of the cranckase for ventilation. This was deemed as a polluter, so they were required to feed this back to the carburetor in the late 60's.

Yeah, well, the EPA has only been bothering with small engines since the 90s. B&S engines have had PCV valves routed to the air filter since the 50s or earlier. It's there for engine performance, NOT emissions. If you leave it open, you will suck in dirt and ruin your engine in short order. Remember, they have no oil filter.