Block off plates

[Stichill_imp]

Like Dubs said, this isn’t crankcase ventilation. The reed valves are part of the PAIR system. Per the manual: “The pulse secondary air system introduces filtered air into the exhaust gases in the exhaust port. Fresh air is drawn into the exhaust port by the function of the PAIR control valve.”

If you have a service manual the explanation and diagram is shown in section 1. Is part of the emission controls.

The crankcase breather is also shown in section one. “The engine is equipped with a closed crankcase system to prevent discharging crankcase emissions into the atmosphere. Blow-by gas is returned to the combustion chamber through the air cleaner and throttle body.”

How does the filtered air, going into the camshaft area above the valves / under the valve cover, end up being drawn into the exhaust port from above?

[Lord Popgun]

There is a hose at the rear air cleaner housing that goes to the PAIR control solenoid valve. From there the air goes out 2 hoses to the reed valves and from there down a tube or port (Pics of head look like a cast port to me and no hose is shown on the part listing or service manual) to the exhaust side of the exhaust valve.

If you really need to know how the port is down, take off a reed cover and assm and look.

For Crankcase breathing, the gasses in the valve cover go out a big hose at the back/top/middle of the cover, through a hose to the front air cleaner housing.

PM me your email address and I can send you a pic of the manual drawings.

[michael1954]

Working on my GS1100E, a compartment on top was crack so I replaced it with an OEM cover. Underneath was a wire mesh, folded over like hotdog about 3 to 4 inches long and about an inch wide. It look to me as some sort of breather to vent gases and the mesh stopped oil, etc from going out. Is this the same item on the Suzuki as the CB?

My next question is why replace these with a different one?

[LakeWylieJoe_imp]

The air for this system is supplied via the airbox and through the PAIR valve where the path splits into two rubber lines that connect to the top of the valve cover (as previously pointed out). Then it enters the valve cover's reed valves over the exhaust cam. Once inside the valve cover, there are four machined passages that run to the rear of the valve cover and the air enters the cylinder head via four small dowels that have small o-rings placed between the mating surface of the head and the valve cover. The head has dedicated passages that lead right to the exhaust port. Pretty ingenious routing.



See the vertical port in the up & down center of the picture.

This system should have no affect on the power delivery as it's a post combustion process. It's simply there to add some outside air into the exhaust stream in an effort to clean up the emissions. If engine runs worse with this system functioning, there must have been some other mods made.

[michael1954]

Hey guys,

I ordered these K Factory block off plates shortly after I got all of that work done, and I finally put them in yesterday. Installation was a snap, (didn't even have to remove the tank!) probably took 5 minutes per side.

Initially I removed all of the diaphragm assembly, then I noticed the dimples/detents in the block off plates corresponded with the screws on top of the diaphragms. The instructions were all in Japanese, so I had to wing it.

[attachment=13445][attachment=13443][attachment=13444]
No more popping on decel, and no more more burbles. Also, the throttle twitchiness is completely gone now!

[attachment=13446]

[PowerDubs_imp]

... and to think some owners (not just CB owners but all makes and models) just rip all these earth-saving-related components out so to gain a few horsepower, and in some cases, an extra +40 dB of rumble.

Blocking the pair makes the bike run smoother. It does not effect power.

Removing the cat does make power.

If you think any of that is 'saving the world'...you should never own a weedwacker, ride in an airplane, get anything delivered by truck (both big rig and ups/fedex)...and certainly not take a cruise ship. The difference in scale is enormous.

[michael1954]

... and to think some owners (not just CB owners but all makes and models) just rip all these earth-saving-related components out so to gain a few horsepower, and in some cases, an extra +40 dB of rumble.

Blocking the pair makes the bike run smoother. It does not effect power.

Removing the cat does make power.

If you think any of that is 'saving the world'...you should never own a weedwacker, ride in an airplane, get anything delivered by truck (both big rig and ups/fedex)...and certainly not take a cruise ship. The difference in scale is enormous.

Blocking the pair makes the bike run smoother. It does not effect power.

Removing the cat does make power.

If you think any of that is 'saving the world'...you should never own a weedwacker, ride in an airplane, get anything delivered by truck (both big rig and ups/fedex)...and certainly not take a cruise ship. The difference in scale is enormous. Thanks for the info. If I have this figured out, my CB1100 is okay as it is, because it runs fine with no popping. My Kawasaki is another question. I removed the entire OEM exhaust system when I installed the Akrapovic Exhaust system & K&N Air Filter. It does have popping on slowing down. So I need to find a way to block the system, correct?

[Lord Popgun]

A quick look at some Kawasaki sites seems to indicate that blocking off their system does not stop the popping. I would suggest you do some research on some of the sites. Google Kawasaki Pair system or KLEEN system and a lot comes up.

[GoldOxide_imp]

... and to think some owners (not just CB owners but all makes and models) just rip all these earth-saving-related components out so to gain a few horsepower, and in some cases, an extra +40 dB of rumble.

Blocking the pair makes the bike run smoother. It does not effect power.

Removing the cat does make power.

If you think any of that is 'saving the world'...you should never own a weedwacker, ride in an airplane, get anything delivered by truck (both big rig and ups/fedex)...and certainly not take a cruise ship. The difference in scale is enormous.

Keep in mind there is "scale of economy" when it comes to transport and pollution.

We think diesel locomotives are massive offenders - and they are. However, the cost to move a ton of carriage 100 miles is something on the order a $1 (I think it is less). That same ton moved by truck is something like $66. This is simply based on fossil fuel consumed.

In addition, gas-powered leaf blowers and weed-whackers (many being two-stroke) have no emission management. Of course, many dino-powered leaf blowers put out a neighbourhood annoying noise emission too.

[NovaCB1100_imp]

Hey guys,

I ordered these K Factory block off plates shortly after I got all of that work done, and I finally put them in yesterday. Installation was a snap, (didn't even have to remove the tank!) probably took 5 minutes per side.

Initially I removed all of the diaphragm assembly, then I noticed the dimples/detents in the block off plates corresponded with the screws on top of the diaphragms. The instructions were all in Japanese, so I had to wing it.

[attachment=13445][attachment=13443][attachment=13444]
No more popping on decel, and no more more burbles. Also, the throttle twitchiness is completely gone now!

[attachment=13446]

I had removed the cat and 02 sensor already when I had a custom exhaust system made. The bike was popping on decel and even from when I got it, it had some throttle twitchiness/snatchiness which was particularly noticeable in u-turns or slow speed maneuvering. The block off plates resolved all of those issues for my situation. Had I not upgraded the exhaust and deleted the cat, I would not have likely done the plates.