Help with identifying engine part

Two · 01-31-2021, 09:19 AM

Fixing up a roketa dual sport I have gotten the engine running but I will not run it for too long because I am scared of overheating due to it missing a part. I have no idea what part this is or what purpose it serves please help me identify.
I’ve added some photos I found on the internet one shows the part and the other shows a cover up plate where the part goes

Two · 01-31-2021, 09:21 AM

Here is the partial part attached to my engine

GronkFries · 01-31-2021, 10:47 AM

Does the other end go into the airbox/intake. Is your bike's picture showing the most likely EGR being blocked off as well. If so use/make a cover plate. Also, take it off and see if it's directly ported to the exhaust valving.

I think my bike has one of those but haven't eliminated it yet. Sometimes an EGR also functions as a carb heater for cold weather applications but being a motorcycle I doubt that matters much.

Also, if it is blocked off look to make sure the airbox doesn't have an open nipple, it should be blocked off as well.

grumpyunk · 01-31-2021, 01:47 PM

I have not figured out for sure if that is an EGR device or a PAIR device. An EGR would take a bit of exhaust gas and mix it with the incoming air, adding some non-burnables to dilute the charge, and reduce peak temperatures. That helps reduce/eliminate the production of NOx particles. Nitrous Oxides - stinky eye burning gases.
I do not think it is an actual EGR because these low-compression engines likely do not produce a high enough temperature to crunch neutral Nitrogens together with wild Oxygens willy-nilly.
A PAIR would use pulses and valving to induce fresh air into the exhaust flow, diluting the concentration of exhaust gases, and also providing some extra Oxygens from the atmosphere(the air cleaner box...) to allow for oxidation of any HC(hydrocarbons- fuel) left over in the exhaust gas. Given a carb bike has no O2 sensor, the resulting exhaust gas could have HCs that would be burned(helped by the catalyst) and result in less unburned HCs released to the atmosphere.
A PAIR system does not hurt anything, and removal likely doesn't do much for performance, if anything. It's a free pulse pump, free of energy consumption, more or less.
Some remove it thinking they are gaining something, but I don't expect there to be much if any gain. Removal of the catalytic lining of the exhaust pipe may open the pipe diameter and allow a bit more free flow of exhaust gas. I think the restriction on flow is apparent at the muffler outlet on most, which is a pretty small diameter. Larger than the catalytic converter ID. No real reason for removal. I think.
What is on the bike should have access to clean air, and some vacuum operated gizmos to make it work or not work. I think.
tom

tknj99 · 01-31-2021, 01:50 PM

It looks like the pair valve device that i removed from my Brozz, although attached in a different orientation.. if it is the pair device, then like mentioned, just fabricate a block off plate and you should be good to go

01-31-2021, 01:47 PM	#4
grumpyunk Join Date: Jul 2018 Location: nw of atlanta Posts: 169	I have not figured out for sure if that is an EGR device or a PAIR device. An EGR would take a bit of exhaust gas and mix it with the incoming air, adding some non-burnables to dilute the charge, and reduce peak temperatures. That helps reduce/eliminate the production of NOx particles. Nitrous Oxides - stinky eye burning gases. I do not think it is an actual EGR because these low-compression engines likely do not produce a high enough temperature to crunch neutral Nitrogens together with wild Oxygens willy-nilly. A PAIR would use pulses and valving to induce fresh air into the exhaust flow, diluting the concentration of exhaust gases, and also providing some extra Oxygens from the atmosphere(the air cleaner box...) to allow for oxidation of any HC(hydrocarbons- fuel) left over in the exhaust gas. Given a carb bike has no O2 sensor, the resulting exhaust gas could have HCs that would be burned(helped by the catalyst) and result in less unburned HCs released to the atmosphere. A PAIR system does not hurt anything, and removal likely doesn't do much for performance, if anything. It's a free pulse pump, free of energy consumption, more or less. Some remove it thinking they are gaining something, but I don't expect there to be much if any gain. Removal of the catalytic lining of the exhaust pipe may open the pipe diameter and allow a bit more free flow of exhaust gas. I think the restriction on flow is apparent at the muffler outlet on most, which is a pretty small diameter. Larger than the catalytic converter ID. No real reason for removal. I think. What is on the bike should have access to clean air, and some vacuum operated gizmos to make it work or not work. I think. tom __________________ vertical and above ground - my daily goal
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01-31-2021, 01:50 PM	#5
tknj99 Join Date: Oct 2020 Location: Central VA Posts: 1,259	It looks like the pair valve device that i removed from my Brozz, although attached in a different orientation.. if it is the pair device, then like mentioned, just fabricate a block off plate and you should be good to go __________________ 2024 Zuma Storm 150 DLX 2019 Beta 430 RRS 2018 VStrom 1000 XT Former China Bikes: Tao DBX1, Brozz 250, CSC RX4, Titan DLX, Templar X
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01-31-2021, 10:47 AM	#3
GronkFries Join Date: May 2019 Location: Maine Posts: 111	Does the other end go into the airbox/intake. Is your bike's picture showing the most likely EGR being blocked off as well. If so use/make a cover plate. Also, take it off and see if it's directly ported to the exhaust valving. I think my bike has one of those but haven't eliminated it yet. Sometimes an EGR also functions as a carb heater for cold weather applications but being a motorcycle I doubt that matters much. Also, if it is blocked off look to make sure the airbox doesn't have an open nipple, it should be blocked off as well.
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