Valve cover issues

[MajBach]

Well, what started out as some advice on suspension and a seasonal fluid change has morphed into a near teardown and rebuild. So far I have changed a tire, changed the brakes, painted some worn parts, removed the relay arm, swing arm, the U-Joint, the stands, all the plastic, changed the fluids, installed another horn and cleaned and lubed everything-feels good to get this deep into it. I still haven’t got the stones to touch my forks, but I did decide today to check my valves. Bike is 60,000 miles and I don’t believe they have ever been checked. The most challenging task since I started has been removing the valve cover. (No - scratch that! I forgot about those damn centerstand bolts

Anyway, manual says to “remove the throttle” cable but I couldn’t for the life of me figure out how. And the step-by-step guide posted on another side says the valve cover can be wriggled out just by moving the loosened throttle cables around a little. Just when I thought that was impossible, I managed.

Anywhoo, two questions came up:

The thermostat inlet pipe was quite corroded with some gunk near the o-ring that mates into the valve cover. At first, I thought this was part of the air induction system and was concerned that some of this crud dropped into the intake manifold. Now, as I type this, I see that this is not a concern - duh.

What IS part of the air induction system though are those ports that are part of the valve cover and have a reed valve inside. The tubes were almost completely clogged with black crud. I am assuming this is some type of crankcase breather? What do they do?

(I took photos but cant seem to recall how to post them)

 

[TomInPA]

That mess of hoses is the PAIR, exhaust air induction system. You could remove all of it and simply install the block-off plates by WynPro (our own forum machinist. https://www.fjrforum.com/forum//index.php/topic/116612-wynpro-air-induction-cover-plates/page-10?hl=%2Bwynpro+%2Bblock+%2Bplates&do=findComment&comment=1098365

It's an attractive solution and will make future access easier.

 

[ionbeam]

...What IS part of the air induction system though are those ports that are part of the valve cover and have a reed valve inside. The tubes were almost completely clogged with black crud. I am assuming this is some type of crankcase breather? What do they do?...

The air induction system is for emissions, it is active until the thermostat opens and then it is only active at idle once the engine is up to operating temperature. The system draws air from the air box, through an air control solenoid, through reed valves and into the exhaust stream. Not only does this help emissions when cold, it also helps prevent the catalytic converter from being overloaded with unburned fuel fumes.

On deceleration or at idle the ECU turns on the air valve solenoid which presents air to the reed valves. On deceleration and at idle, during the exhaust stroke the reed valves are drawn open allowing air to flow through passages in the cylinder head which leads the air into the exhaust flow just before the head pipes. The injected air allows a secondary burn of left-over fuel in the exhaust. When decelerating from any significant speed the injected air will also cause popping in the exhaust headers as the fuel ignites. When the thermostat opens, the ECU senses that the engine has warmed up and it stops signaling the air injection valve when the engine is running over idle speed. The air injection valve is kept closed by having +12 volts across the solenoid, the solenoid opens the valve and flows air when the 12 volts is turned OFF. Unplugging the solenoid makes it ON all the time.

The reed valves and the passages will become carbon coated by exhaust back-streaming which will cause the reed valves to not fully seat which will cause more back-streaming. When installing blank-offs the air box port gets capped, the solenoid removed and the reed valve ports are covered by the WynPro jewelry. The solenoid connector is left open. The engine is significantly decluttered and valve checks become easier. The catalytic converter may choke a bit during cold engine operation -- but since it is out of sight and out of mind it doesn't matter