Yamaha R3 Forums banner
1 - 20 of 28 Posts

·
Super Moderator
Joined
·
1,330 Posts
Discussion Starter · #1 ·
Does the use of a block-off plate also require a PCV or other fuel controller?
 

·
Registered
Joined
·
1,515 Posts
Does the use of a block-off plate also require a PCV or other fuel controller?
This is a loaded question.

Typically, you do 3 things at the same time:
1. full exhaust
2. PCV with new tune map
3. block-off plates
( Optional: racing air filter )
 

·
Super Moderator
Joined
·
1,330 Posts
Discussion Starter · #3 ·
Can I install the block-off plate to remove the air pump but without PCV / full exhaust? Or is the O2 sensor going to be a problem. How can the air pump equipment be removed without PCV / full exhaust.
 

·
Registered
Joined
·
1,515 Posts
Can I install the block-off plate to remove the air pump but without PCV / full exhaust? Or is the O2 sensor going to be a problem. How can the air pump equipment be removed without PCV / full exhaust.
You don't want to mess with it. Leave it alone.
Why do you want to remove it?
:|
 

·
Registered
Joined
·
255 Posts
The main reasons for the block-off are to reduce the "popping" with aftermarket exhaust systems, and to get proper a/f ratios when tuning. There's really no reason to remove the air pump; if you're looking for weight savings there are better ways to lose 2 pounds.
 

·
Super Moderator
Joined
·
1,330 Posts
Discussion Starter · #6 ·
The main reasons for the block-off are to reduce the "popping" with aftermarket exhaust systems, and to get proper a/f ratios when tuning. There's really no reason to remove the air pump; if you're looking for weight savings there are better ways to lose 2 pounds.
Yeah for weight savings. I only have slip-on. So block-off plate is a definite no-no without PCV and tuning?
 

·
Super Moderator
Joined
·
1,330 Posts
Discussion Starter · #8 ·
If you want to save weight with a minimum of hassle swap out your battery for a lithium one. Hard Racing recommended the AntiGravity ones.
Already did battery, tail tidy, slip-on. Want to keep rear pegs for now.

I'm still not 100% clear on the answer here. If I install the block-off plate without PCV / tune, then do Bad Things Happen? Should I sell the $25 kit that I bought?
 

·
Registered
Joined
·
196 Posts
I been running a blockoff plate with stock exhaust and no pcv. This as done in preparation for aftermarket exhaust and pcv in the future. my bike hasn't blown up yet.
 

·
Registered
Joined
·
1,515 Posts
I'm still not 100% clear on the answer here. If I install the block-off plate without PCV / tune, then do Bad Things Happen? Should I sell the $25 kit that I bought?
I have no idea how the system can work properly when you block the air-valve on a stock bike.
The Oxy sensor has a limited range.
The ECU wants to "see" air from that valve entering the exhaust system.
If it doesn't "see" it... what do you think it will do?
It will find an overly RICH mixture, and it will try to lean out the fuel delivery from the injectors.

You are confusing the ECU by blocking off the air-valve system.

If you are doing a full exhaust, and a ECU-flash or PCV with new map, then everything can work together and be okay.

You can't just do one piece of the puzzle. You have to do it ALL. It works together as a matched system.

:|
 

·
Super Moderator
Joined
·
1,330 Posts
Discussion Starter · #11 · (Edited)
The ECU wants to "see" air from that valve entering the exhaust system.
If it doesn't "see" it... what do you think it will do?
It will find an overly RICH mixture, and it will try to lean out the fuel delivery from the injectors.
Yes this is my exact concern (ecu thinks rich, leans out even more, burning piston tops, etc). I just don't know how flexible the system is, or what it actually does for real. Seems as though one person has done it, and hasn't blown up yet. Not sure that's enough data points for me though, heh. The air pump is on DECEL though right, so it might not matter much. So I might try anyway.

Would PCV + slip-on + stock headers/cat + block-off plate be considered okay?
 

·
Registered
Joined
·
1,515 Posts
Would PCV + slip-on + stock headers/cat + block-off plate be considered okay?
I understand money is an issue... but why don't you just leave your bike alone, until you have the money to do everything all at once?
( Full exhaust, PCV, block-off plates, Tune/Reflash )
 

·
Super Moderator
Joined
·
1,330 Posts
Discussion Starter · #14 · (Edited)
I understand money is an issue... but why don't you just leave your bike alone, until you have the money to do everything all at once? (Full exhaust, PCV, block-off plates, Tune/Reflash)
It's not money heh, you don't understand. Just want to remove unnecessary weight from the bike. I don't really want to mess with PCV / full exhaust / afr directly. If there was a light weight exhaust system that maintained the stock cat's back-pressure, I would be interested.

Eat quinoa, not cheeseburgers? :D
In mid-January I weighed 179 pounds. I'm already down to 153 pounds as of last week. Target is 145 pounds. Used to be a half-marathon runner at 82 minutes. Then I caught pneumonia that like to have killed me, and I gained a ton of weight with nerve damage and a fractured leg, etc ... crap snowballs. Was 128 pounds at one point, but that was too dang thin.
 

·
Registered
Joined
·
196 Posts
Would PCV + slip-on + stock headers/cat + block-off plate be considered okay?
I understand money is an issue... but why don't you just leave your bike alone, until you have the money to do everything all at once?
( Full exhaust, PCV, block-off plates, Tune/Reflash )
Isn't it obvious? He's been bitten by the mod bug! haha as have most of us
 

·
Registered
Joined
·
120 Posts
I think the heaviest part of the system is the stock headers and the catalytic converter. So changing just the slip on won't save much weight.

Plus it's the cat that's the most restrictive part of the exhaust system. As long as you leave that in place, I don't think there's much need for an ECU or block off plate
 

·
Registered
Joined
·
1,515 Posts
Isn't it obvious? He's been bitten by the mod bug! haha as have most of us
Well, you guys need to get bitten by the "riding bug", so you can stop fooling around with your little bikes, and start RIDING them!
:laugh:
 

·
Super Moderator
Joined
·
1,330 Posts
Discussion Starter · #18 ·
Well, you guys need to get bitten by the "riding bug", so you can stop fooling around with your little bikes, and start RIDING them!
:laugh:
That's why the block-off plate, rear mud guard, and 3/4 levers are here in a box. I just finished the diode/resistor led running light mod + R6 throttle tube, and have to actually do some miles before messing with the bike again.
 

·
Registered
Joined
·
196 Posts
I read up more on this. This question has been asked a few times on other Yamaha forums, also on what exactly the air injection system and blockoff plate does.

AIS injects air post combustion at idle allowing unburnt fuel to be burnt up as it is exiting the exhaust (usually inside the catalytic converter). The AIS was designed as a system to clean emissions at idle and produce better smog test results. It is only active when you let off the gas, it's meant to fool emissions testing.
Blockoff plate simply disables the AIS.

So, my conclusion is this: running the blockoff plate, no pcv on stock exhaust system - the only issue may be that your catalytic converter may wear out sooner due to the unburnt gasses passing through. Your exhaust pipes and can might reach higher temperatures. No engine issues because AIS is post combustion. Many other brands of bikes don't even come installed with AIS.
 

·
Registered
Joined
·
1,515 Posts
AIS may be "post-combustion", but it injects air upstream of the Oxy-sensor. The ECU takes a reading from the Oxy-sensor, and tells the injectors what to do.
If the AIS was after the Oxy-sensor, then it wouldn't matter at all.
 
1 - 20 of 28 Posts
Top