Can anybody tell me what the vacuum switch does?

[av_mech]

Just curious. The clymer manual doesn't say much of anything about it. It's the little silver unit mounted behind the radiator overfill tank. It has a hose coming the crankcase and a hose that goes to the top bar of the frame under the gas tank. I'm doing some wiring mods and have the bike pulled apart and I started wondering what it was.

[Chuck B]

Originally Posted by av_mech

Just curious. The clymer manual doesn't say much of anything about it. It's the little silver unit mounted behind the radiator overfill tank. It has a hose coming the crankcase and a hose that goes to the top bar of the frame under the gas tank. I'm doing some wiring mods and have the bike pulled apart and I started wondering what it was.

Sounds like its apart of the Air Injection system i.e. 50 state smog equipment. With a closed throttle fresh air is injected into the exhaust port burning unburned fuel from the cylinder. Install an aftermarket exhaust can and you'll have lots of popping and back firing as the fuel ignites.

See Wymanwinn for proper block off plates if you chose to remove this and the other related smog equipment your bike is installed with.

[av_mech]

Originally Posted by Chuck B

Install an aftermarket exhaust can and you'll have lots of popping and back firing as the fuel ignites.

See Wymanwinn for proper block off plates if you chose to remove this and the other related smog equipment your bike is installed with.

Yep, that's totally what it is. It's called the Clean air system. I've got an FMF power bomb header and Q4 silencer. Lots of popping! CAS is going bub bye!

[BAMBAM650]

Hey AV...............how do you like the Powerbomb? Do you notice any performance gains with it? Did you do anything for a heat shield?