Vacuum hose

[ddebonis]

For better or worse, motorcycles are exempt from smog inspections in CA.

http://www.dmv.org/ca-california/smog-check.php

[MrRiden]

There is so much wrong information out there on this system it's incredible. I maintain the system on my '82 LS and have no issues. Removing the system will not alter performance. It will not require re-jetting. It does not "inject" air into the exhaust and it will not melt your valves. It is a passive system that allows fresh air into the exhaust pipe under acceleration (low manifold vacuum) only. It will not permit fresh air to flow at idle (high manifold vacuum). The fresh air valve is normally open, closing under vacuum from the carbs which are Tee'd together. If your system pops on deceleration it means that the valve is hanging open. Removing the system means that there is one less source for a fault to occur. That's it. Even a well known "guru" has it muddled. If you Google "r65 pulse air system" You'll find everything from praise to damnation of it. Keep it or toss it. It's up to you but do it only because you want one less maintenance item.

[Luca]

MrRiden is right.  I just checked my owners manual.  On page 76:

Pulse Air System
This system supplies additional
oxygen to the exhaust gas and
thus improves the emission va-
lues without weakening engine
performance.
When releasing throttle, this sy-
stem is cut off, controlled by
vacuum pipes connected to the
carburetors.  This device is also
maintenance free.

With that said, the exhaust valves/seats were already a problem on these bikes, but the issue isn't full-blown melting, it's recession caused by premature wear, such as on burned valves.  If the fresh air does add heat to the exhaust, it could be helping the common problem along... or not.  And hey, maybe header wrap is just as bad.  I prefer safe over sorry on this one.

What does bug me about the system is that it kept my right hand carb bowl from coming off the carb.  Also, if a check valve or the diaphragm ever goes, the valves are not serviceable.

[montmil]

I removed the Pulse Air System from both my R65s for the simple reason that I thought it was cosmetically fugly.

[Matt Chapter]

I thought it was cosmetically fugly.

Mine never made it back on after the motor swap due to "fiscal constraints".