Mixture screws.

Does anyone happens to know how many turns out are the mixture screws on a FJS 2008? I just want to start from there to synchronize throttle bodies after

I don't believe that there is a starting point. You need a manometer or a duel vacuum gauge to adjust the vacuum at idle. My album shows a diy manometer I made to sync the both injector body vacuum. The Honda service manual has the procedure to sync the vacuum. Page 5-103.

I do know the entire procedure and I have also a manometer (carbtune).You can easily synchronize both throttle bodies nomatter how many turns out are the screws.Thats not right though.You start with OEM setting and you finish with fine tuning by a manometer.For instance you start with two turns out and after fine tuning you have 2.1 and 1.9 for each.Thanks anyway

I know I'm joining the discussion late but are you talking about the two brass screws, one each on either side of the idle screw. I accidentally turned one, then the other thinking one was the idle screw until I found the idle screw hidden under that vacuum tube. I discovered this only after removing the seat which I tried to avoid while adjusting the idle. I think I returned them about where they were but really not sure at all. If we in fact are talking about those two screws did you ever get an answer to your question. I don't have a manometer nor do I want to buy one. I would love to be able to turn these screws in all the way and then back them out 3 or 4 turns and call it a day. What kind of damage can I cause if I leave then alone now. The Swing seems to run just fine right now, by the way.

Well, if you don't want to use an easily made DIY manometer* then I guess the '2 or 3 turns' method is gonna be just fine.


*https://m.youtube.com/watch?v=Y_WDF6glD5k

Νow here's my question.1.5...2...2.50..or 3 turns out.With 3 out the idle rises and the adjustment screw can not decrease idle rpms less than 1500 any more.Thats why I'm asking where the oem turns out are more or less

The adjustments are only a starting point. If you don't have a manometer and you say that your Swing is running okay, then I would suggest leaving it as is. The vacuum may be different between your bike and mine. The manometer will equalize the vacuum for both cylinders at 1200-1300 RPM.

Throttle body screws are not mixture adjusting screws. They are just air bleeds add more or less air behind throttle plate.

On an carburetor they adjust some fuel flow only on the idle circuit.. Fuel injection is different.
Turning them out can raise idle speed some but varies with system. FI system with a vacuum leak will cause a high idle.

Throttle bodies can become dirty reducing airflow. Idle adjusting screw will open them raising idle speed or opening bleed screws. Balancing them equal vacuum is what you want. Smoothest idle.

Gentle turn them all the way in. Back out 1 turn each and try to balance vacuum. If its low adjust idle screw slightly in and start over.