internal pressure?

schnowz schnowz at
Sun Mar 18 07:32:21 PDT 2007

 Thanks guys.. Live and learn.. I wasn't familiar with this on bikes, only 
on autos
 Unless you have a vacum leak or exhaust popping I don't see the point in 
removing it though....being as it's not gonna increase performance...

 Pete S
Commie EnvironMENTAList Bastard

----- Original Message ----- 
From: "Stephen Hampson" <shampson at>
To: "'schnowz'" <schnowz at>
Sent: Sunday, March 18, 2007 5:15 AM
Subject: FW: internal pressure?

> Hi, Steve Northrop explains it better I could see below.
> Cheers
> Steve
> -----Original Message-----
> From: Steve Northrop [mailto:blackgpz at]
> Sent: 17 March 2007 22:54
> To: gpzlist at
> Subject: Re: internal pressure?
> The KLEEN air system is a passive air injection system.  Air is drawn from
> the airbox, through the reed valves in the valve cover, through four
> passages in the cylinder head. This passage is the small circular opening
> right next to the spark plug with the hollow roll pin in it you can see 
> when
> you have the valve cover off. Each passage leads to an opening in the
> exhaust port. The venturi effect of the exhaust gasses passing this 
> opening
> is what draws the air in. This is why it is important to make sure the
> "figure 8" gaskets are in good shape. Whether the KLEEN air system is 
> intact
> or if the reed valves have been blocked off, a low pressure area exists 
> such
> that if it is not sealed well beneath the valve cover, oil can be sucked
> into the exhaust. I tapped the passages and epoxied in some 1/8 pipe 
> plugs.
> The PCV system is the hose that comes out of the rectangular cover at the
> back of the engine above the transmission. Remember the crankcase is open 
> to
> the transmission so it vents both.
> Steve in Western NY
> '96 GPZ1100
> '02 Daytona 955i
> "You Can't Fix Stupid", Ron White
> ----- Original Message ----- 
> From: "schnowz" <schnowz at>
> To: <gpzlist at>
> Sent: Saturday, March 17, 2007 7:15 PM
> Subject: Re: internal pressure?
>> Steve,
>> I'm not understanding this,where is it connected to the exhaust port?
>> The diagram shows it connected to the airbox, inlet manifold, and rocker
>> cover.
>> I thought it was acting similar to a PCV valve???
>>  Pete S
>>> From: "Steve Northrop" <blackgpz at>
>>> Subject: Re: internal pressure?
>>> To: "GPZ LIST" <gpzlist at>
>>> Message-ID: <000c01c7680b$a0467710$6900a8c0 at DB3HB511>
>>> Content-Type: text/plain; format=flowed; charset="iso-8859-1";
>>> reply-type=original
>>> Dave,
>>>     The absence or presence of the KLEEN Air system has no bearing
>>> whatsoever on jetting. This passive system introduces air at the exhaust
>>> port, it does not add any additional air to the engine. Blocking off the
>>> reed valves is no problem because they have nothing to do with venting
>>> internal pressure to begin with. This vent is at the rear of the engine
>>> above the transmission with a hose that goes to the airbox if you are
>>> still
>>> using one. The reed valves in the KLEEN Air system act as one-way valves
>>> so
>>> when exhaust gasses pass by the opening in the exhaust port, it will 
>>> draw
>>> some air with it. The reed valves keep exhaust reversion pulses from
>>> pushing
>>> exhaust gas back through the system. Sorry, but putting it back on was a
>>> lot
>>> of work for nothing.
>>> Steve in Western NY
> -- 
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> 12:33

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