Breather Filters

Greetings again to all. Anyone find a breather filter to be practical rather than just a "bling thing"? Getting a carb & intake issue squared away on this CV730 and just found a brand new filter in a box of spare parts . . .

. . . Should have been more specific, this is one of those open cone shaped lookin' things like the air intakes . . .

. . . looks like it would allow for easier release of pressure than the factory can as far as restriction goes

Could you post pics of it and where you want to use it please? You actually want to use it as a PCV breather and not an air filter right? I will say the big downside to all K&N style filters (wire mesh/cotton guaze) is they will let more "crud" through than a paper or foam filter. If you're using it as a PCV breather then it SHOULD be fine but I really don't think it will be more than a fancy looking accessory which is some people's thing! Lol

. . . I was reading through an older post (Doc & other members) re efficacy vs necessity in routing the tube back to the intake and for this engine I'm thinking the cleaner air it can breath is more of a benefit than the amount of draw from the head.

. . . worth noting perhaps, when I opened up the intake to begin diagnosing the surging issue (my other post) I notice some, but not significant, residue where the tube comes through the plate and about as much into the carb itself. As well, I soaked & flushed the breather can thoroughly looking specifically at what drained and it was cloudy but not as much as I expected considering it was the first for it (may have put a new one on in Spring of '20 . . . don't remember) . . .

Now here's a question, the typical operation of this machine is far more "stop & go" with intermittent sprints than say, a full on high rev "romper". Any benefit to the slight bit of vacum draw here?

I would personally leave the breather intact and sealed as it will prevent dust and other crud from getting in but to each their own. The residue you speak of is oil vapor recirculating back into the engine and although it leads to some buildup in the cylinder/combustion chamber (which can be cleaned periodically) it actually has some benefits e.g. a little extra lubrication to the top piston ring which not only lowers friction (for less heat and more power) but also would help seal the top ring better too which increases compression (more power)!

I do have to say I think it's pretty cool you have a "catch can", is it factory or did you add it? Not sure if there would be a benefit to extra vacuum draw but I also don't understand fully where you're speaking of it being. The cloudiness of what you drained is most likely just water/condensation thats suspended/absorbed in the oil and is normal to a degree. They design oils to suspended the "water" so it's not droplets getting between surfaces.

My bad on the use of "can" . . . This would be a factory . . .

Wow that's factory, neato! So that's how it normally is and it doesn't really route to the carb or intake? If that's the case disregard what I said in your particular situation! Lol

. . . "breather SEPARATOR" . . .

This tube is a longer one I just stuck on for the pic. A shortened length will have a 90° pvc elbow to attach through the back of the mounting plate so the tube doesn't crimp again. I have seen vids where the tube drops directly in front of the carb however, I don't know whether that's a set factory position or a personal tweek by those folks . . .

Ah good old Dr.Evil... lol.

From what I see in the service manual it's supposed to route back into the intake so I'd leave it hooked up as it should be. You COULD plug the hole in the intake and just let the breather seperator vent but you'll be inviting dirt and dust into the engine oil and crankcase even with that filter you've shown. That's all the info and advice on the subject I have to offer, do with it what you will it's your engine. Maybe someone else has something to add?

JJF3RD wrote:

This tube is a longer one I just stuck on for the pic. A shortened length will have a 90° pvc elbow to attach through the back of the mounting plate so the tube doesn't crimp again. I have seen vids where the tube drops directly in front of the carb however, I don't know whether that's a set factory position or a personal tweek by those folks . . .

You can trim it so it's only sticking into the intake an inch, if you want to put an elbow on the end to direct the vapor into the mouth of the carb you can but it's not required.

I would venture a guess that a "danglin' drop" like that would be more "arm chair engineering" in an attempt at getting the most draw through the tube being closer to the suction. All said, "if it works for them" . . . .