Just my opinion but.... I would not buy or use any tool with fewer readouts than the number of cylinders that the bike has. I synch. six cylinder engines with two separate four tube manometers side by side. As these work on physics rather than calibration or adjustment, as long as they are at the same vertical height, all tubes will read correctly even across two manometers. Four cylinder vacuum gauges are easy enough to get that I would not consider a twin gauge and jumping between two cylinders with each gauge. When you make an adjustment on one T.B. or the balance screw between T.B. #'s 2 and 3, ALL the T.B. vacuum levels will change. It is really pretty important to watch all cylinders at the same time. .....Brian
I dissagree....if you get settings jumping around at each adjustment, you have valve issues.....
here's my $0.02 get some popcorn.....
Thanks for the kind offer MOB. I would like to take you up but I am unclear how to use it for theC14 since the first step in the manual calls for comparing all 4 cylindars:
"If any vacuum is not within specifications, first synchronize
the balance of the left (#1, #2 throttle valves) and
right (#3, #4 throttle valves) assemblies.
Example:
#1: 240 mmHg
#2: 250 mmHg
#3: 230 mmHg
#4: 240 mmHg •With the engine at the correct idle speed, equalize higher
vacuum of #1 or #2 (for example 250 mmHg) to higher
vacuum of #3 or #4 (for example 240 mmHg) by turning
the center adjusting screw [A]."
How would you do this with the Twin Max?
this bike is really no different to adjust than any, the original C10 included..and
I have ad-nauseum explaned adjusting those carbs using the Twin-Max.
There is absolutly no reason this tool will not work here, and I will explain.
Now, I will say you cannot "measure actual vacume" with this tool, but the synch does not require this anyways, you are only adjusting to make everything "equal" to the "highest" value found...
the reference in your post of a value of XXX mmhg refers to a reading on a true manometer, filled with Mercury, which is drawn upwards thru the bore of the tube (that bore measures 1mm diameter).
All vacume gages use this measurment, as it has been made standard internationally now. (Used to be inches of mercury, wayyyy back in time), so you will understand that height of the column of mercury when that gage is used will show column heights relating to the "mm Hg".... Hg being Mercury.....
when you synch on this bike, you need to pull the big air switch hose (right side of bike) out from the airbox, and plug both ends prior to adjustments. Idle speed should be set to 1100 rpm using the throttle adjust knob. Engine should be WARMED up, and at operating temp.
enough about that...The Twin Max works like this.
With the meter sensitivity set HIGH, the meter is adjusted to center, with the hoses disconnected. This adjustment is crucial. You then connect the meter to 2 sources (cyl #1 and #2), start the engine and note the side (either A or B ) that is the higher of the 2. Shut down the engine, and insuring you haven't tweaked the adjustment knob, re-attach the meter to the other 2 sources (cyl #3 and #4), recording which of those 2 is the higher one. Shut down again, and repeat this operation one more time comparing the highest reading cylinder from each of the pairs....record. don't adjust anything, including the meter, it still should be zeroed when no vac is being drawn.
You adjust each bank (left or right) separatly, then synch the 2 banks.
By your reference chart above you will attempt to:
#2 is the highest reading t/b, it will be the point to achieve on the other 3 cyl's.
adjust #1 up to equal #2 using the pilot bypass screw on the back of #1 tb
adjust #3 up to equal #4 using the pilot bypass screw on the back of #3 tb
now with the meter attached to #2 and #4, bring the right bank (#4) up to equal that of left bank(#2)
using the center throttle link adjusting screw.
Verify all are equal by comparing #1 and #3...they should be good now.
If the vacumes are realllly off, which they shouldn't be, you may have to remove, and clean all the pilot screws....the manual is your friend.
Section 2-18
Having a single, and accruate true vacume gage is also a good idea, so you can actually measure the high one to see what it really is (xxx mmhg)
Synchronization is simply Comparing 2 sources, and making them equal, there is absolutly no reason to have to read 4 different meters, which are all physically different from each other, and connot possibly be "equal" in thier real values.
I have verified this on every major tool out now, using "Tee"s and inline precision shutoff valves with the twinMax in the loop, and have proof that while most are good, none are as accurate in comparing A to B....period.
The Twin Max is the most accurate, Clean, AND Simple 2 source Comparitor on the market.
welcome to the age of electronic analysys.