Service manual

Table Of Contents

Installing the Audiovox CCS100 Cruise Control on the

Honda Pacific Coast PC800 Motorcycle

Page 5

Vacuum System

The CCS100 cruise control requires a constant source of vacuum. Vacuum is what supplies the

mechanical power for the throttle actuator. The Pacific Coast's two carburetors each have a

vacuum source. The vacuum source on the #1 (left) carburetor is used to provide vacuum to the

auto fuel valve; however, the one on the #2 (right) carburetor is normally unused and is capped

off. It is possible to use only one vacuum source to supply the servo, but this may not provide

sufficient vacuum under all situations. It is recommended that both carburetor vacuum sources

should be used.

When a vehicle is using cruise control while traveling up long hills, more suction is needed for

the servo to pull the throttle further and harder. On vehicles with larger engines, there is often

enough suction available to provide all the needs of the cruise control servo without needing

assistance. But on small vehicles such as the PC800, the meager suction provided by the

carburetors can easily be overcome by hard pulls, causing the cruise control to slacken off.

Consequently, the PC800 needs the assistance of a vacuum reserve. The vacuum canister (VC)

provides this extra vacuum reserve to help the CCS100 maintain a constant pull.

Since there is limited space within the PC800's fairings within which to mount equipment, the

size of the vacuum canister will be limited in order to fit inside. Since it may be impractical to

install a single, large volume vacuum canister, if more vacuum reserve is needed, two or more

smaller vacuum canisters may be connected in series with additional lengths of vacuum tubing.

Also, it is not required that the vacuum canister be located next to the servo; they could be

separated by several feet, as long as there is sufficient length of vacuum tubing.