Balancing TBs Revs Rising - Bell Crank Screw

I'm trying to balance my TBs and wishing I'd bought a manometer

First attempt 3mm tubing (it's what I had) water moves too quickly, oil gets too many air bubbles in it

Second attempt 4mm tubing - stolen from the fish tank - oil still bubbles up, water still moves too fast - engine has digested a bit of both !

I've tried my daughter & my wife holding the throttle at 3.5 - 4k and they swear that as I adjust the bell screw it's raising the revs up to 5k-7k

Surely it can't and they are moving their hands ?

I've reset my TPS and the base value is correct but it only reads 85% at full throttle - is that right ?

Thanks

Revs rising with bell crank adjustments is normal. I'm always on my lonesome when I do it, so I adjust, then close the the throttle and then back to 3.5K and adjust again. It's an iterative process.

You need dampers in your manometer.

The throttle reading is butterfly angle. So that's 85°, not percent.

Thanks

Yes it's far more volatile than I thought

The Bell Crank screw operates like the throttle stop for the left hand body.

Yes but I was just surprised that adjusting it could raise the revs so much

I'm waiting for a biking mate to pop over