Triumphrat

jimmy bush

Has anyone used vacuum gages hooked to the balance tubes between the carbs to balance the carbs on classic bonnevilles and how does the results compare to the "old" way?

htown16

I bought some from an outfit in the UK that are not gauges but use stainless steel inserts in tubes similar to the old mercury filled tube type. I'll have to look tonight to get their name and address if you're interested. They work really well, but vacuum guages should too. You may not be drawing enough vacuum at idle to get a good reading. Screw the idle adjustment screws in til your getting a good reading, adjust each til you get the same reading on both guages, then back each idle screw out the same number of turns til your idling about 800-900 rpm.
You can also use the guages to check whether the cables are adjusted right and lifting the slides at the same time. As you open the throttle, the gauges should move in parallel if the cables are right. If not use the adjusters on the top of the carbs to set. Then reset idle.

JohnG

Does anyone know what to expect for a reading off the guages at idle or just above? Due to the trade that I work in, vacumn guages are a dime a dozen so I'm putting together a setup where I can compare both carbs as they're running and dial them in. Hopefully it will eliminate the headaches I experienced last summer as I tried to sort out my T140E. When I did finally get them somewhat correct. . . what a difference! I'm hoping the guages will make it easy and more accurate.

drlapo

I use the mercury manometer on all my bikes and it works great on:
BMW R80
T140E
05 thruxton
Moto guzzi Lemans
much easier and more acccurate than the old pull a plug method

jimmy bush

Thanks for the responses. I have found (actuall they have been burried in the bottom of my old tool box you 20 years & I just forgot I had them) a set of gages that have 4 glass tubes with steel balls that levitate with the vacuum. Haven't tried them on the Triumph yet but plan to soon. Don't know if they still work but they used to work fine on the 4 (or anything #) cylnder bikes.