Graves Garage-Why use Smog Block off Plates? What do they do?

Graves Garage-Why use Smog Block off Plates? What do they do? This seems to be a popular set of questions over here at Graves Motorsports. Most people say to me..... they dont make any horsepower so why should I spend the $35 and take the time to install them?. Here is some info on the benefits of using the smog block off plates on just about every model motorcycle. *This is for off road racing applications and not meant to be used on the street. If you have something to add please feel free. From the factory most motorcycles will come with a pair valve system on them. This is basically an air pump that pulls fresh air from your air box, sends it through a bunch of hoses, and then pumps that fresh air into your exhaust ports on your cylinder head. There is unburned fuel that makes it through the combustion stroke, exits the cylinder head, and makes its way down the exhaust system to finally exit into the atmosphere. The pair valve system adds fresh Oxygen to the exhaust so that as the unburned fuel comes into contact with the extremely hot catalytic converter, the additional fresh air will aerate the fuel for a more efficient burn and keep the exhaust cooler. This equals less emissions being released into the atmosphere and lower emission readings when tested. Here are some of the main reasons you should consider installing the smog block off kit on your motorcycle. (1) The pair valve system really requires a catalytic converter to complete its job of burning off excess fuel. Once you have installed a full race system and have removed the cat, all this fresh air will do is mix with the unburned fuel vapors and beginning to burn up while exiting the exhaust. This create the popping and back firing that throws those incredibly cool but damaging flames out of your exhaust. Great for night riding, but terrible for tail sections and leg hairs. To eliminate this add the smog block off plates. (2) If you decide to have your bike dyno tuned then you cannot run the pair valve system because as it adds oxygen to the exhaust gases. This causes dyno sniffer (reads the air/fuel mixture exiting the motor) to pick up false A/F readings due to the additional Oxygen that is added after combustion. When it reads the extra O2 it thinks the bike is running lean and will compensate by adding fuel to the fuel map. Now you have a map that is much fat (too much fuel) and the bike will run terrible. The person that is tuning the bike will have to pinch these off every time you dyno the bike. To eliminate this add the smog block off plates. (3) The tubes, pump, and wires that are included in the pair valve smog system add unnecessary clutter and weight to the motorcycle. To eliminate this add the smog block off plates. (4) This is the last reason I have found to run the plates but it is NOT A FACT. It seems, not everyone have noticed this and nobody has proven it right or wrong so do not take this as absolute. It could very well be just by brain acting up. I believe I felt it help my engine breaking a little. Before I installed them I felt like the bike (08 R6) had a really strong engine breaking and would pop and back fire a lot on decceleration. When I installed the plates I would swear that the engine breaking became more suitable. It was not as abrupt and not nearly as strong. Again this was only a guess and has no proof to it, however I did talk amongst a few tech savvy buddies and we worked out a somewhat scientific theory. Possibly as the hot engine gases are pouring smoothly out of the cylinder head like melted butter this cold fresh oxygen is forced into the exhaust ports. This could very well slow those gases down and create more back pressure which in theory could possibly cause stronger engine breaking. So?..maybe Im not crazy. http://www.gravesport.com/Products/images/fullsize/AB011.jpg Taige Webster Graves Motorsports http://www.gravesport.com

Excellent write up. I experienced the popping as well until I installed the Graves block offs. And it does feel as if the engine breaking is better. The smog block offs are relatively easy to install too.

I have something to add, my graves full system popped like all h*ll on the decel until I installed these block off plates http://i80.photobucket.com/albums/j180/stevewfl/bigthumb.gif

Excellent write up. I experienced the popping as well until I installed the Graves block offs. And it does feel as if the engine breaking is better. The smog block offs are relatively easy to install too. Thanks for the added credibilty. We are currently in development of smog block offs for the wife but it is yet to function properly. Still a ton of engine breaking and smog pours out of both ends... LOLOLOL TW

great info! forum discount :sing:

Yeah, I agree with the engine braking theory. It seems to decel much smoother now ( I just did this mod recently).

Your smog block off plates are nice and help with the extra clutter on top but can't I accomplish the same thing with some 99 cent vinal caps from the hardware store? Sure it's not as cool looking and may weigh a gram or two more but the end result should be the same and it only took me a few minutes to do if fact the hardest part was figuring out how to get the electrical connector apart. This post is in no way ment to discredit or disrespect you or any of your products. Personally I think Graves is top notch Im just asking.

I'd be very interested in hearing about this as well. I have removed the stock baffles in my exhaust and have a terrible popping sound on decel and have been thinking about the block-off plates. Can I accomplish this with the caps as mentioned above?

In addition to the benefits that Taige has outlined in the first post, I enjoy the fact that changing the spark plugs become easier. And I LOVE the sound when I'm blipping down through the gears at high RPM on the track now :fact

Your smog block off plates are nice and help with the extra clutter on top but can't I accomplish the same thing with some 99 cent vinal caps from the hardware store? Sure it's not as cool looking and may weigh a gram or two more but the end result should be the same and it only took me a few minutes to do if fact the hardest part was figuring out how to get the electrical connector apart. This post is in no way ment to discredit or disrespect you or any of your products. Personally I think Graves is top notch Im just asking. This is absolutely true. You can make your own part and accomplish close to the same task. My thought is that if Im going to take the time to take the bike apart, unplug the electrical connector (they can be a pain in the A;-), and then put it all back together I might as well do it perfect the first time. Like you said it leaves the engine compartment clean, with less clutter, the plates look good and it is just a tight finished package. You get basically the same effect with the plugs like you said but it would always bug me thinking one fell off or maybe its leaking.......with the plates you are assured that its , clean, bolted tight, and looks good. I did it to mt 08 R6 recently and it took a little time, cost a little money but it was super clean and I don't have to worry about it. Thanks, Taige

I'd be very interested in hearing about this as well. I have removed the stock baffles in my exhaust and have a terrible popping sound on decel and have been thinking about the block-off plates. Can I accomplish this with the caps as mentioned above? I am not completely familiar with the removal of stock baffles. My thoughts are that the popping has just become louder due to the removal. What used to be absorbed by the mufflers is now being released into your ear drums. I believe a lot of the popping is unburned fuel mixed with the addition of fresh O2 being pumped in from the smog equipment. With this being said, I do believe the smog block offs would help this considerably. The good thing is they help in other ways so no matter what they are worth the investment of time and $$. You need to plug the smog equipment off if you dyno the bike plus they look good and clean up the engine compartment a little. All around I believe its a good addition. Hopefully it does help with the exhaust popping. Thanks, Taige

I have been doing a lot of reading on the graves block off plates. So much that I ordered a set. I am hoping they will help with the popping from my GYTR cans. Now I got the plates in, and don’t get me wrong they are very nice. But can someone please tell me where I can fined, what’s the ward…. OH ya, Instructions? Maybe a picture or two. I guess I r not smart and need pictures. But I am a CH46 guy. This is the first bike I have ever worked on. Any help would be great. By the way, it’s an 07 R1.

I have been doing a lot of reading on the graves block off plates. So much that I ordered a set. I am hoping they will help with the popping from my GYTR cans. Now I got the plates in, and don?t get me wrong they are very nice. But can someone please tell me where I can fined, what?s the ward?. OH ya, Instructions? Maybe a picture or two. I guess I r not smart and need pictures. But I am a CH46 guy. This is the first bike I have ever worked on. Any help would be great. By the way, it?s an 07 R1. There should have been instructions in the package and they should have a complete schematic of the parts involved. Anyway its no problem....if you go to the link below and click on AB011 a pdf of the instructions will download. That should give you everything you need to get through this. http://www.gravesport.com/Tech_Support/instructions.php Most important. make sure to retain the rubber gasket that is on the cover now as it works as your agkets with the new plates. Basically just remove the aluminum plate only, then replace it with ours. Everything else from there up to the airbox can be unplugged and removed. Put the supplied cap on the airbox outlet where you removed the tube from. make sure everything is tight and flush, and reassemble (not forgetting anything imporatant). Im sure there are many methods to this so you should get some pretty helpful hints from these guys on the forum. Thanks, Taige

according to to '09 yec kit manual--the yec ais plug set (5vy-a4890-70) also includes 4 dowel pins ( part #93608-16m16). the manual says to remove the cylinder head cover and install these dowel pins in addition to the block off plates. how come the graves kit does not include these or is this not neccessary to do?

I am having some trouble with my bike. I put a set of block off plates on my bike. After that my bike just went to hell. It runs really bad, and cuts out with a poor idle at start up. Before I put the plates on she ran great. But after I need to start the bike and let it set to allow the idle to rise from 800 rpm to 1100 rpm. If I don’t and give her some gas she cuts out. I was thinking it was a cold condition but it happens all the time. I was riding for about 30min shut my bike down for about a min and she did the same as before. Idle was low and jumpy and slowly climbed to 1100 from about 800. Any help would be great.

I am having some trouble with my bike. I put a set of block off plates on my bike. After that my bike just went to hell. It runs really bad, and cuts out with a poor idle at start up. Before I put the plates on she ran great. But after I need to start the bike and let it set to allow the idle to rise from 800 rpm to 1100 rpm. If I don?t and give her some gas she cuts out. I was thinking it was a cold condition but it happens all the time. I was riding for about 30min shut my bike down for about a min and she did the same as before. Idle was low and jumpy and slowly climbed to 1100 from about 800. Any help would be great. Are you running any fuel management? (power commander/bazzaz etc?) Is your O2 sensor connected to the exhaust? Was the bike ever dyno tune and did they remove or plug the pair valve system during the tuning? You need to have your O2 sensor disconnected, power commander mapped properly, and your smog equipment blocked off. If all these have been done then.......... Unfortunately there must be something that was overlooked on the install. The only function of the Pair valve system is to add oxygen to the exhaust ports. It help lower emissions, however anything added or taken away after combustion has taken place should not effect the motor like you are talking about. Adding oxygen to the exhaust or taking it away will not effective the running of the bike at the level you are explaining. It might effect it a bit but I doubt you would notice it. In fact if anything I would make it run smoother not adding cold air to your exhaust as it exits the cylinder head. Possibly there is a leak in the plates. Did you use the stock rubber washer that sits between the valve cover and the plates? Are you sure you did not disconnect anything else and are you sure you put the plug on the air box correctly after removing the lines? I can almost guarantees it is something that was overlooked in the install. Check the things i mentioned and keep me posted, Im definitly interested in hearing the out come. Thanks, taige

according to to '09 yec kit manual--the yec ais plug set (5vy-a4890-70) also includes 4 dowel pins ( part #93608-16m16). the manual says to remove the cylinder head cover and install these dowel pins in addition to the block off plates. how come the graves kit does not include these or is this not neccessary to do? To be honest I have never installed the YEC plug set so i cannot give you an accurate answer on this however i will be asking the race team this question. There is really only one function that blocking this system off performs so i assume the outcomes of each are the same. Maybe the YEC system not only block it off at the reed valves but also at each individual exhaust port. I cannot see how this would be any more beneficial to the performance of the motor but again Im not 100% on this question. Both kits stop air flow from being released into the exhaust and plug off the air box. Anymore than that seems redundant ????? If I find the true answer i will be sure to pass it on. Thanks, Taige

Are you running any fuel management? (power commander/bazzaz etc?) Is your O2 sensor connected to the exhaust? Was the bike ever dyno tune and did they remove or plug the pair valve system during the tuning? You need to have your O2 sensor disconnected, power commander mapped properly, and your smog equipment blocked off. If all these have been done then.......... Unfortunately there must be something that was overlooked on the install. The only function of the Pair valve system is to add oxygen to the exhaust ports. It help lower emissions, however anything added or taken away after combustion has taken place should not effect the motor like you are talking about. Adding oxygen to the exhaust or taking it away will not effective the running of the bike at the level you are explaining. It might effect it a bit but I doubt you would notice it. In fact if anything I would make it run smoother not adding cold air to your exhaust as it exits the cylinder head. Possibly there is a leak in the plates. Did you use the stock rubber washer that sits between the valve cover and the plates? Are you sure you did not disconnect anything else and are you sure you put the plug on the air box correctly after removing the lines? I can almost guarantees it is something that was overlooked in the install. Check the things i mentioned and keep me posted, Im definitly interested in hearing the out come. Thanks, taige He's local to me, Taige. So I'll go through those things with him in the next week. I'll have him post what we find.

do all the r1's have the smog gear on them, im in new zealand, or is it just a usa spec. i have standard cans but no cats on my 07, i do hear a slight kinda pop but nothing major and it does sound kinda cool.

Graves Garage-Why use Smog Block off Plates? What do they do? This seems to be a popular set of questions over here at Graves Motorsports. Most people say to me..... they dont make any horsepower so why should I spend the $35 and take the time to install them?. Here is some info on the benefits of using the smog block off plates on just about every model motorcycle. *This is for off road racing applications and not meant to be used on the street. If you have something to add please feel free. From the factory most motorcycles will come with a pair valve system on them. This is basically an air pump that pulls fresh air from your air box, sends it through a bunch of hoses, and then pumps that fresh air into your exhaust ports on your cylinder head. There is unburned fuel that makes it through the combustion stroke, exits the cylinder head, and makes its way down the exhaust system to finally exit into the atmosphere. The pair valve system adds fresh Oxygen to the exhaust so that as the unburned fuel comes into contact with the extremely hot catalytic converter, the additional fresh air will aerate the fuel for a more efficient burn and keep the exhaust cooler. This equals less emissions being released into the atmosphere and lower emission readings when tested. Here are some of the main reasons you should consider installing the smog block off kit on your motorcycle. (1) The pair valve system really requires a catalytic converter to complete its job of burning off excess fuel. Once you have installed a full race system and have removed the cat, all this fresh air will do is mix with the unburned fuel vapors and beginning to burn up while exiting the exhaust. This create the popping and back firing that throws those incredibly cool but damaging flames out of your exhaust. Great for night riding, but terrible for tail sections and leg hairs. To eliminate this add the smog block off plates. (2) If you decide to have your bike dyno tuned then you cannot run the pair valve system because as it adds oxygen to the exhaust gases. This causes dyno sniffer (reads the air/fuel mixture exiting the motor) to pick up false A/F readings due to the additional Oxygen that is added after combustion. When it reads the extra O2 it thinks the bike is running lean and will compensate by adding fuel to the fuel map. Now you have a map that is much fat (too much fuel) and the bike will run terrible. The person that is tuning the bike will have to pinch these off every time you dyno the bike. To eliminate this add the smog block off plates. (3) The tubes, pump, and wires that are included in the pair valve smog system add unnecessary clutter and weight to the motorcycle. To eliminate this add the smog block off plates. (4) This is the last reason I have found to run the plates but it is NOT A FACT. It seems, not everyone have noticed this and nobody has proven it right or wrong so do not take this as absolute. It could very well be just by brain acting up. I believe I felt it help my engine breaking a little. Before I installed them I felt like the bike (08 R6) had a really strong engine breaking and would pop and back fire a lot on decceleration. When I installed the plates I would swear that the engine breaking became more suitable. It was not as abrupt and not nearly as strong. Again this was only a guess and has no proof to it, however I did talk amongst a few tech savvy buddies and we worked out a somewhat scientific theory. Possibly as the hot engine gases are pouring smoothly out of the cylinder head like melted butter this cold fresh oxygen is forced into the exhaust ports. This could very well slow those gases down and create more back pressure which in theory could possibly cause stronger engine breaking. So?..maybe Im not crazy. http://www.gravesport.com/Products/images/fullsize/AB011.jpg Taige Webster Graves Motorsports http://www.gravesport.com I installed a set of your block off plats on my 2007 R1. As soon as I started the bike it ran like crap. I played around with my power commander but it only helped a little. My bike was running so bud with the wondering idle and cutting out at startup when giving it any throttle input before waiting about 5 min. I removed the plates. The problem went away. I have put them on and off 4 times. Thinking I could try something new each time I tried. As of now they are off the bike and I am getting the flame out my GYTR cans. I am also running an Akrapovic y-pipe to get rid of the cat. What do I need to do to get the block off plates to work?

ive got a 07 R1 and am looking to order the block-offs to help with the decel popping. ive got the a&r race baffles in the stock cans, still have cat, and no map. my question is can i run the block-offs with this set up or will i need to get it tuned?