Tweet
Someone feel free to correct me if im wrong, but it was in the name of fuel efficient and power output to use a vac advance. The issue that I see is that it works in tandem with an electronic ignition unit thats a little touchy and you may suffer poor performance and fuel economy with it capped.
-
1979 XS1100F "Roxy" (my first bike
) - '91 Suzuki GSX1100 Fairing, BMW bags, Cheap ABS Trunk, aftermarket cruiser seat, MAC 4-2 exhaust, Heavy Duty folding kickstart, XS11 Special signals and gauges, Blade Fuse Conversion, Dynacoil Greens w/ ballast bypass, SS brake lines -
Vacuum Advance
It's there for a reason. Engine needs a total number degrees of timing advance. If you disengage the vacuum advance, you will retarded the timing. This can cause mechanical problems to the engine. Don't do it.1981 XS1100H Venturer
K&N Air Filter
ACCT
Custom Paint by Deitz
Geezer Rectifier/Regulator
Chacal Stainless Steel Braided Brake Lines
Chrome Front Rotor & Caliper Covers
Stebel Nautilus Horn
EBC Front Rotors
Limie Accent Moves On In 2015
MikeComment
-
The timing advance is controlled by the TCI starting in '81, the 78-80 models have a mechanical timing advance behind the timing plate, the TCI has nothing to do with it.2H7 (79) owned since '89
3H3 owned since '06
"If it ain't broke, modify it"
☮Comment
-
So my understanding at this point is that there are two ways the timing is advanced. One is engine speed - activated by the "centrifugal advance" behind the plate and the other is "vacuum advance" for low-speed throttle response maybe? To bad Yamaha didn't get this issue straightened out for the earlier models. Whipping wires around to perform fast mechanical stunts is not a good approach. Arrrr Matys.....Comment
Comment