Yamaha F40 BETL synchronizing screws factory settings?

[Boatmann]

What is initial factory setting or starting position for Yamaha F40 BETL (2005) synchronizing screws when synchronizing carbs? How many turns from closed position when I need to start from scratch? Factory settings or starting positions are mentioned on service manual for throttle stop screw and pilot screw, but not for synchronizing screw. Cleaned the carbs and have difficulties synchronizing them with Carbtune Pro because I don't have previous positions written down.

[boscoe99]

When you mention synchronizing screws are you talking about what Yamaha calls the throttle valve screws?

The throttle valves are opened or closed to get the correct vacuum setting.

[Boatmann]

Yes, I mean those for vacuum setting. Service manual just talks about synchronizing screws.

[boscoe99]

What service manual do you have? What is the document number?

[Boatmann]

67C-28197-3K-11 from ManualsLib for F30A/F40B.

[boscoe99]

Is there an LIT-18616- XX-XX number on the manual? Need the XX numbers.

[boscoe99]

I see the problem. In one SM Yamaha refers to the adjustment screws as synchronizing screws and in a different SM they refer to them as throttle stop screws. Damn Yamaha and their crappy data.

Just crack all three throttle plates open slightly so that the motor will run. Start the motor and let it worm up. Then proceed to set the idle RPM. Then synchronize the throttle plates. Adjusting the idle as necessary as you go. Readjusting the throttle plates as you go. One will affect the other so a bit of fiddling is required.