Will adjusting the idle screws affect carb sync?

[gatorcat]

I have a Honda BF90, and the carbs have been rebuilt so there are not any end caps on the screws. I had trouble with the idle, and I adjusted a couple of them. Is it really necessary to have the carbs re-synced? Will the idle screws really change the vacuum pressure?

 

[pvanv]

Re: Will adjusting the idle screws affect carb sync?

Yes.

 

[Nick on the Bad Habit]

Re: Will adjusting the idle screws affect carb sync?

The only way to adjust idle speed is to adjust the lowest carb the vertical rod will that connects all the carbs together will keep carbs in sync. The other screws you tried to adjust will take the carbs out of sync! The carbs need to be put back into sync using a synchronizer. It can be done at home of you get the right tools, but does take some learning and practice to get it right. I found a good synchronizer at a motorcycle shop for about $100.
Nick