Originally Posted by victoRR
I've read all over this board of the Starter Valve being mentioned. What is the significance of this part and how can it be adjusted? More info would be appreciated.
Starter Valve Synch is Honda's term for synchronizing all four throttle bodies, yes, even on fuel injection systems. Some Honda dealer techs have not heard of it, but it's right there in the manual. Basically the vacuum is set and non-adjustable on throttle body #1, you equal out the other three using a guage (Morgan Carbtune II or similar) and adjusting the 7mm nut for each (#2,#3, and #4). The idea is that all (4) are in synch with promises of better gas mileage, smoother response, smoother idling, etc.
Do a search as there's been quite a few threads.
I've done it several times, I think the manual suggest every 5,000 miles, and I can tell the difference. I had this nagging vibration, bike would hual ass, but that vibration (even at low speeds/rpm) drove me crazy.
I changed my plugs, air filter, oil, Starter Valve procedure and the bike was like new, I could fly into the rev limiter just as smooth as butter.
Others have done the Synch only to have it purring at idle.
There's more info out there, hope this helps.
Edit: Here's a link that shows pictures of the CarbtuneII Morgan Carbtune II