carb ?

[boba]

on a car i would think this was a carb air fuel screw. but on my bike i dont know there are 2 of them one on bottom and one on the side. What actually do they do? and how do you know if there adjusted right? ( if they are air fuel screws )

[Steve]

First things first, here, WHAT BIKE???

By the slightly fuzzy picture, it appears to be a set of VM carbs on a '79 or older bike. That is the pilot fuel screw on the bottom of the carb. How far out depends on what has been done to the engine. Somewhere between 3/4 and one full turn out from lightly seated would be close. The screw on the side is the pilot air screw. Start with that one 1 1/2 to 2 full turns out, then tweak it for maximum idle rpm when the engine is fully warmed up.

.

[BassCliff]

Hi Mr. boba,

Feel free to download the VM carb manual from my website. There's a copy of the VM carb cleanup guide there too.


Thank you for your indulgence,

BassCliff

[boba]

screws

my camera isnt the best, but it does work afterall. well i knew i forgot something, the pic is from 78 550 and i have a 79 850 with the same carbs. it will leak fuel out the tubes now and then even when its cold. one day it put out a quart of fuel just sitting, would that screw on the bottom have something to do with that?

and on my 550 well i dont know yet, its in the process of being put back together ( what the pic is from ). just need 1 more cylender oring, ( i dont kniow what they are for, they dont seal meet up with anything, other than where the aluminum and cast iron meet.

[Nessism]

Those are pilot fuel screws. That is not the source of your leak; most likely you have a stuck float. Honestly, your bike is 30 years old and needs a carb refreshing. Go to cycleorings.com and get a kit along with the intake boot o-rings. Clean the carbs out properly and you will be way ahead of the game. http://www.thegsresources.com/files/vm_carb_rebuild.pdf

[SqDancerLynn1]

If it put out a qt while parked you have two problems. Leaking petcock and leaking /dirty float needles