TOPIC:

I have a 2001 zr7s that I just bought. 19,000 miles. I'm about to adjust the valves so I figured while I'm at it I'm going to remove the pair system to create some extra space for future engine work.
I've done it on liquid cooled engines before without a second thought but the zr7s is an air/oil cooled 750.
My concern is ... Will this cause a hotter running engine? I understand this will remove only a tiny amount of air circulation from within the motor but should I be concerned?
The exhaust may also have a catalytic converter built in and I'm also wondering about the effects of a pair delete may have on it. I'm not sure sabot the cat tho, as I'm still awaiting my service manual in the mail.

Removing the system will have no effect on engine temperature. The system introduces clean, filtered air into the exhaust port in order to dilute the exhaust gasses to make the EPA happy. I am about 98.9% sure there is no cat in the system.

FWIW. Some new aftermarket ZR7 mufflers listed on EB seem to indicate that the oem Kawasaki muffler system didn't have a catalytic converter.



Subaru SEEC-T system. introduced around 1976. The Kaw system seems kind of similar in function.

Thank you gents,
I didn't think it would have an effect on engine temps but had to ask.
But in researching I also read that the PAIR system helps keep the exhaust valves cool and, as a result, will help keep the valves and seats in better shape.
Do you have any thoughts on that?

blipco wrote: Thank you gents,
I didn't think it would have an effect on engine temps but had to ask.
But in researching I also read that the PAIR system helps keep the exhaust valves cool and, as a result, will help keep the valves and seats in better shape.
Do you have any thoughts on that?

I don't see how introducing air after the exhaust valves have closed, with the specific intension of increasing the "burn" in the exhaust system, could have a cooling effect. I've removed the air injection system from my 750 by plugging the ports in the head with grub screws and installing a 750 Turbo valve cover which doesn't have the reed valve hardware. The bike certainly doesn't run hot. Install an oil cooler if you are worried about heat. That's a definitive mod.

A ZR-7S should have an oil cooler already, so he should be good to go.

Nessism wrote:

blipco wrote: Thank you gents,
I didn't think it would have an effect on engine temps but had to ask.
But in researching I also read that the PAIR system helps keep the exhaust valves cool and, as a result, will help keep the valves and seats in better shape.
Do you have any thoughts on that?

I don't see how introducing air after the exhaust valves have closed, with the specific intension of increasing the "burn" in the exhaust system, could have a cooling effect. I've removed the air injection system from my 750 by plugging the ports in the head with grub screws and installing a 750 Turbo valve cover which doesn't have the reed valve hardware. The bike certainly doesn't run hot. Install an oil cooler if you are worried about heat. That's a definitive mod.

I figured the same but I read somewhere that the PAIR moves air across the back of the exhaust valves keeping them cooler.
The non PAIR engines seem to do ok without it though.
The zr7s does have an oil cooler so I'm good there.