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Main Area => General GS500 Discussion => Topic started by: lucas on October 08, 2015, 10:35:04 PM

Title: Should I put a PCV or filter on the air vent on the carbs?
Post by: lucas on October 08, 2015, 10:35:04 PM
I want to remove the long vent hose from the carbs in my GS.  If I do that, though, the pathway for dust and grime to enter into the carbs gets much shorter.

Would putting a one-way valve on the plastic "tee" work?  How about one of those little baby cone filters?

How would capping that vent affect performance?

Lucas
Title: Re: Should I put a PCV or filter on the air vent on the carbs?
Post by: cWj on October 08, 2015, 10:46:23 PM
http://wiki.gstwins.com/index.php?n=Upgrades.AirFilter
Title: Re: Should I put a PCV or filter on the air vent on the carbs?
Post by: lucas on October 08, 2015, 10:48:51 PM
I neglected to do any searching.  I did a google search and it brought up a whole bunch of discussion threads on a forum called... gstwins.com  whoops.  maybe someone can delete my post or banish it from the land.
Title: Re: Should I put a PCV or filter on the air vent on the carbs?
Post by: fakejimmymorgan on October 09, 2015, 04:00:19 PM
I put a lawnmower air filter on mine. Basically because it's what I had lying around in the shed. Would eventually like to drill the end of my pods and use a t piece to plumb the air back into the filter and make it look neater. (http://images.tapatalk-cdn.com/15/10/09/09fdee19647b8b9ab757fecd815370ce.jpg)


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Title: Re: Should I put a PCV or filter on the air vent on the carbs?
Post by: Big Rich on October 09, 2015, 04:42:45 PM
Maybe I'm just confused, but here's what I'm thinking:

Jimmy: the only reason to put any filter on the crank case breather hose is to keep spiders (and other creepy crawlers) out of the hose. There is actually a steel (?) mesh filter inside the engine under the small cap the hose attaches to.

Lucas: are you talking about the actual vent hose attached to the carbs? If so, the biggest problem is airflow near the end of the hose..... sometimes when people shorten / re-route that hose, air passing over the end can create a small bit of turbulence. That turbulence creates a stumble in flow at higher rpms.
Title: Re: Should I put a PCV or filter on the air vent on the carbs?
Post by: lucas on October 09, 2015, 09:21:04 PM
I ordered a PCV valve and I have a small plastic bottle that was part of a brake bleeding kit that will work well as a catch can.  I'm going to attach those two top the vent on the top of the engine.

But that is a separate issue from what I'm asking about, really.  I am asking about the vent on the actual carbs.

Now the vent on the top of the carbs... I was planning on just running with no hose since that looks better but maybe Suzuki didn't put a hose there just to make things ugly.  What is the function of that vent in the operation of the carbs?
Title: Re: Should I put a PCV or filter on the air vent on the carbs?
Post by: fakejimmymorgan on October 09, 2015, 09:28:41 PM
Isn't it just part of emission reduction?


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Title: Re: Should I put a PCV or filter on the air vent on the carbs?
Post by: lucas on October 10, 2015, 12:02:38 AM
No idea, wish I knew.  Looking at my carbs (I have them out for a thorough cleaning and re-jet) those air passages appear to go through to the crescent shaped thing over the intake plenum.

Can't really tell if they go anywhere else, kinda hard to see in there.

Am I seeing this right?  Is this a short-cut for air to get past the air filter?
Title: Re: Should I put a PCV or filter on the air vent on the carbs?
Post by: lucas on October 10, 2015, 01:00:20 AM
Ok I did some reading.  I have the older style carb that does not have the emissions filter thing on the top of the carbs.

I took a closer look at my carbs and discovered that the vent allows air under the diaphragm, into the intake air, and into the float bowls.

In other threads I read someone refer to this as an "atmosphere reference" which makes sense that it would be used under the diaphragms.  It does not make sense to me that this would also be open to the intake air stream... this means any dust or schmoo can make its way around the air filter to the engine.

I feel like this vent should be filtered, what do you guys think?

Ps - I haven't been able to upload photos, anybody else having trouble?
Title: Re: Should I put a PCV or filter on the air vent on the carbs?
Post by: fakejimmymorgan on October 11, 2015, 02:52:32 AM
I'm all up for filtering (even if it's considered unnecessary) living in my part of Audtrslia there's plenty of fine iron ore dust that easily clogs up air filters in my town so I'm not taking the risk of it getting into my engine even if it already had a screen type filter.


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