air/gazoline mixture & jets size.

[Anonymous]

Hello,

I have installed a 4into1 Jardine and stock K&N airbox on my 1977 GS 750B and the mixture is too rich. There is black smoke when I rev the engine and the exhaust is smelling gaz. I opened the air screws and the engine iddles better but the air mixture is still not right. Could someone suggest me jet sizes and brands that would work fine with a Jardine and stock K&N airbox on my bike???

Many thanks and keep on riding!

[SqDancerLynn1]

do you still have the slide type carbs on your 77GS bike??? There is also a fuel screw underneath the carb in front of the fuel bowl turn the screws in to lean the mixture I have a 79GS850G I tried 3/4 turn out, was to lean settled on 1 1/8 for the outer two carbs and 1 1/8- 1 1/4 for the center two to hopefully help them run cooler. Hard to get to with carbs on the bike but if you remove the air box and loosen the intake boot clamps you should be able to turn them without disconnecting the thro or choke?cables

[Anonymous]

I USE A SCREWDRIVER BIT ABOUT INCH AND A HALF LONG FOR THAT PURPOSE.

[Anonymous]

Many Thanks for your suggestions

I will try to adjust the carbs air intake and let you know about the results...