PAIR Valve vacuum hose

will6576

Registered
Morning/Evening,
Just gave my Gen 1- 2000 an oil change and filter, noticed the PAIR Valve vacuum hose is disconnected from the number 4 throttle body and re routed under the starter clutch housing, the bike is running fine and the number 4 throttle body nipple has been blanked off.
the bike is running absolutely fine apart from popping on deceleration.
Should i reconnect the hose or let sleeping dogs lie? everything on the pair valve is standard and have done over 4000 miles without a problem.

Thanks for any replies in advance,

Mark.
 
Take the PAIR system off and block the holes above the exhaust outlets. You'll be fine
 
This mod was done, to scavenge vaccum from the crankcase. The idea is less friction to overcome the pressure built up in the crankcase. I did it when I still had my stock exhaust. It seemed to make a slight improvement.
 
TallTom, could you please elaborate? I'd like to know more about this crankcase vacuum mod
 
OK the PAIR Valve is essentially a vacuum pump. So you take the main PAIR valve line off the PAIR pump and hook it up to the crankcase vent line at the top of the CC, instead of where it sucks in air from the airbox. You block off the airbox port. Now you are applying a suction to the top of the CC. That takes the positive pressure in the C/C and makes it less positive. It isn't strong enough to suck it to zero, but it makes it less positive. The theory is, your engine internals have less rotational resistance, rotating against a pressurized cc. Thus less energy used to overcome this atmospheric resistance. It isn't a rocket ship mod, but it does seem to make a noticeable difference in her feel of crisper RPM climb.
 
Thank you for the replies, the main hose from the PAIR is still in the Air box not Crank case, that is what i couldn't work out.
it is as if someone had done a little tinkering and didn't know where the vacuum hose went, tried the bike out and found to be ok and then left it off.
as long as it is not damaging my bike being left off i am happy with that,

Thanks,

Mark.
 
OK the PAIR Valve is essentially a vacuum pump. So you take the main PAIR valve line off the PAIR pump and hook it up to the crankcase vent line at the top of the CC, instead of where it sucks in air from the airbox. You block off the airbox port. Now you are applying a suction to the top of the CC. That takes the positive pressure in the C/C and makes it less positive. It isn't strong enough to suck it to zero, but it makes it less positive. The theory is, your engine internals have less rotational resistance, rotating against a pressurized cc. Thus less energy used to overcome this atmospheric resistance. It isn't a rocket ship mod, but it does seem to make a noticeable difference in her feel of crisper RPM climb.
Do you know if this mod changes the AFR ?
OK the PAIR Valve is essentially a vacuum pump. So you take the main PAIR valve line off the PAIR pump and hook it up to the crankcase vent line at the top of the CC, instead of where it sucks in air from the airbox. You block off the airbox port. Now you are applying a suction to the top of the CC. That takes the positive pressure in the C/C and makes it less positive. It isn't strong enough to suck it to zero, but it makes it less positive. The theory is, your engine internals have less rotational resistance, rotating against a pressurized cc. Thus less energy used to overcome this atmospheric resistance. It isn't a rocket ship mod, but it does seem to make a noticeable difference in her feel of crisper RPM climb.
Do you know if this mod changes the AFR readings?
 
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