[brko]

I looked hard but couldnt find any help on this forum regarding removal of pair system. I am thinking of doing it one of these days but I not sure what to do and how.
Anyone out there done it and has some tips photos?
It would be greately appreciated.

 

[off-the-planet]

Activmoto mentions having done it on this thread: http://www.xrv.org.uk/forums/showthread.php?t=16807
(scroll down to #3),
Might be worth contacting him....

 

[Guest]

I looked hard but couldnt find any help on this forum regarding removal of pair system. I am thinking of doing it one of these days but I not sure what to do and how.
Anyone out there done it and has some tips photos?
It would be greately appreciated.

Hi Brko,
Removing the PAIR system is not going to have any effect on performance and if you do it in isolation you’re going to be emitting more hydrocarbons into the atmosphere.
It’s a straight forward job but procced at you're own risk.
Remove the control valve from behind the radiator fan. Take all the pipes off from the engine. The vacuum pipe on the front carburetor inlet needs to be replaced with a blanking screw ideally with an aluminum, fiber or brass crush washer. (I don't rememebr if the original has a crush washer you can use)
The PAIR air intake from the air box needs to be blanked off, it is located under the front of the air box, it is important that you make a good airtight seal because this intake is on the filtered side of the air box. I found a tight fitting rubber plug.
Take all the pipes you have removed and select a couple of sections that will run between the reed valves on the engine. You will have to make a join in the pipe, you can use some plastic joints from the pipes you’ve taken off. The pipe I fabricated runs from the rear valve under the right side of the frame to the front reed valve. You have to select the tubes with the best corner shapes as these pipes are formed, also before cutting make sure you have the tubes with suitable internal diameters for the plastic connector. Some of the pipes have larger diameter ends than others but the ID are very close.
If you don’t want to bother with the original pipes just get some suitible pipe and connect the reed valves. But you have to route the pipe so it does not stop you putting the air box back on.

The picture shows the pipe below the frame, held by the large cable tie, you can see the join to the right of the cable tie. Also you can see the inlet blanking scew, bottom left side.

Let us know how you get on

Steve

 

[Guest]

The vacuum pipe on the front carburetor inlet needs to be replaced with a blanking screw ideally with an aluminum, fiber or brass crush washer.

Surely using a rubber cover for the existing pipe stub (like BMW use on the balancing stubs on their boxer throttle bodies) would be easier? Not just during the conversion but also whenever you need to balance the carbs.

 

[brko]

Thank you everyone.
This is going to come handy when I start pulling it apart.

 

[wheeliebin]

Nice job Activ, never thought of linking the two reed valves, I'm in the process of making up two blanking plates to replace the reed valve covers, but your way seems a lot simpler.

 

[Guest]

Nice job Activ, never thought of linking the two reed valves, I'm in the process of making up two blanking plates to replace the reed valve covers, but your way seems a lot simpler.

A blanking plate would be a tidy option. The other idea instead of joining the reed valves with a pipe would be just to plug the valve inlets. I just did not have anything to make a tidy job.

If anyone finds anything to plug the valves let everyone know.

Steve

 

[piguglyshandydrinker]

A blanking plate would be a tidy option. The other idea instead of joining the reed valves with a pipe would be just to plug the valve inlets. I just did not have anything to make a tidy job.

If anyone finds anything to plug the valves let everyone know.

Steve

On my 1st bike I removed the red valve coveres, tapped them and loctite'd a short m10 stud into each, the next bike I used wellnuts (like what holds the screen in place. These are good for sealing up the airbox stub too.

I left the vacuum takeoff stub in place, cut a short length of vacuum tube and inserted a self tapper into the end to blank it off - this leaves this tub in place for carb balancing.

As said, there is no benefit to carrying out this mod, other than removing some clutter.

Phil