carb tunning with vacuum gage

[jw228w]

i have 1998 V6 2 stroke 150hp.carbs have been cleaned but i would like to learn how to max out the mixture screw for best efficiency.can hooking up vacuum gages help with this?is there a place on carbs to hook this up ?any manuals out there to explain how to do this for this amateur DIY?thanks

 

[rodbolt]

Re: carb tunning with vacuum gage

if its a yamaha it cannot be done as they have no A/F screws.
the A/F is done by the pilot fuel and pilot air jetting and the screw just lets in more or less of what the jets feed it.