Block off plates

[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]

 

[Stichill]

Those look exactly like the OEM reed valve in the valve cover of my CBR250R. It vents crankcase blow-by out of the valve cover.

 

[PowerDubs_imp]

Good job- but no need.

The pop off the main supply line hose to the airbox and plug it. I used a standard vacuum cap from the local auto parts store- small enough to invert and stick in the hose- worked perfect- and then put the hose back on the airbox. Easy enough to remove if needed...and my valve cover looks normal.

Those look exactly like the OEM reed valve in the valve cover of my CBR250R. It vents crankcase blow-by out of the valve cover.

The parts may be the same- but no, they aren't for crankcase vent- they blow in, not out. Air injection - the AI part of PAIR.

 

[NovaCB1100_imp]

Good job- but no need.

The pop off the main supply line hose to the airbox and plug it. I used a standard vacuum cap from the local auto parts store- small enough to invert and stick in the hose- worked perfect- and then put the hose back on the airbox. Easy enough to remove if needed...and my valve cover looks normal.

Those look exactly like the OEM reed valve in the valve cover of my CBR250R. It vents crankcase blow-by out of the valve cover.

The parts may be the same- but no, they aren't for crankcase vent- they blow in, not out. Air injection - the AI part of PAIR.

The parts may be the same- but no, they aren't for crankcase vent- they blow in, not out. Air injection - the AI part of PAIR.
Thanks Powerdubs,

I also did the air injection removal with my Thruxton, and there was a very similar procedure as you describe above for the Triumph aircooled twins. Either way, very pleased with the results! Now for suspension....

Oh and a new battery as the OEM died this morning. 7 years, not too bad.

 

[Stichill]

Good job- but no need.

The pop off the main supply line hose to the airbox and plug it. I used a standard vacuum cap from the local auto parts store- small enough to invert and stick in the hose- worked perfect- and then put the hose back on the airbox. Easy enough to remove if needed...and my valve cover looks normal.

Those look exactly like the OEM reed valve in the valve cover of my CBR250R. It vents crankcase blow-by out of the valve cover.

The parts may be the same- but no, they aren't for crankcase vent- they blow in, not out. Air injection - the AI part of PAIR.

Well, I'll defer to your knowledge, 'Dubs. It may serve an identical function on my CBR. I thought it was a vent due to the amount of toasted carbon on the parts underneath it.

 

[michael1954]

Would someone explain to me what these do? I have never heard of them.

 

[Tev62]

They have been around in one form or another for a long time. Many might not use a valve though and can be much more rudimentary. There is a nice article here on it. You many of seen crankcase breathers near the crank area of the engine with little pod filters on them. This is to allow the engine to get rid of excess pressure without feeding the oily mist back into the inlet side of the bike.

https://motorcycleinth.com/article.php/Crankcase-Pressure_Engine-Performance/

 

[Lord Popgun]

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.”

 

[Tev62]

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.”

Oh very cool, no doubt driven by Euro or Californian emmission regulations. I like the little pop on the over run myself.

 

[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.

 

[Stichill]

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.