Question about TB balancing

[Guest jmnvhc]

I'm probably going to balance the TB this weekend and had a question on Ian Johnston's write up.

 

The step that reads: "Attach your manometer -- TwinMax, mercury carb sticks, or water manometer, whatever. Attach it to the vacuum nipples right at the intake flange."

 

Well on my bike, and in the bike in the picture, there are hoses attached to the vacuum nipples, so

 

a) What are they? My guess is that it serves to shut off fuel feed when engine isn't running?

 

What do I do with them when balancing the TB? Again, my guess is that while the engine is running I should pinch them off, then shut off the engine and remove them?

 

Or maybe they're like the RH idle set screw... totally redundant and should be removed?

 

 

Thanks,

 

Jose

[jrt]

leave the vacuum nipples on the bike- it makes it easier to tune when you do want to get at them.

The vacuum ports should be blanked off or plugged at all times when the bike is running- I have a hose that connects the RH and LH side. Connecting the two ports might contribute just a tiny bit to balancing the right and left intake (but I doubt it). I think if you follow the hoses, LH and RH, that are on your bike, you'll probably find that they are the same hose. Just pop it off and connect the manometer.

If you run the engine (for a short time) with an open vacuum line in the intake, it won't do any damage, but the bike won't run correctly. So, no need to pinch it off first, then turn on or off the motor or any particular sequence like that.

[Guest Nogbad]

My Carbtune came with nipples that replace the blanking screws in the intake flanges. These are plastic, so I always remove them and put the plugs back. Work of 5 minutes.

[Guest jmnvhc]

Ahhhh... they're the same hose...... INGENIUS!

 

Thanks.

 

 

leave the vacuum nipples on the bike- it makes it easier to tune when you do want to get at them. 

The vacuum ports should be blanked off or plugged at all times when the bike is running- I have a hose that connects the RH and LH side.  Connecting the two ports might contribute just a tiny bit to balancing the right and left intake (but I doubt it).  I think if you follow the hoses, LH and RH, that are on your bike, you'll probably find that they are the same hose.  Just pop it off and connect the manometer. 

If you run the engine (for a short time) with an open vacuum line in the intake, it won't do any damage, but the bike won't run correctly.  So, no need to pinch it off first, then turn on or off the motor or any particular sequence like that.

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[Alex-Corsa]

My Carbtune came with nipples that replace the blanking screws in the intake flanges. These are plastic, so I always remove them and put the plugs back. Work of 5 minutes.

You can also get these brass ones again from carbtune highly recomended. I got mine and ordered an extra set of brass screws ,looking great now and have no fear fo braking them.

Contact Sean at Carbtune he'll be glad to assit.

Great tool that it, after setting the TPS I have synchronised the bike in minutes,

[docc]

Unless your hoses still go to the vapor recovery cannisters from the fuel tank. The only way there would be one hose from one intake to the other is if some un-named sort removed the recovery cannisters.

 

"Sir...I am not aware of such an operation nor would I be at liberty to discuss such an operation if it were to have existed. Sir."