carb ???

[richardgrhett]

my carbs are kicking my butt!! iv got the 22 vm carbs on my 79 550 the pilot fuel screws are set to one turn out and top air screws are 3/4 out and im STILL rich.. i guess my first question is the top adjustment screw is the air fuel ratio right? well iv been adjusting like in is to lean out and out is to richen am i correct?? it seems to not be affecting my mixture this way sorry for the elementry question but i need a foundation to build off of .... thanks guys

[Nessism]

my carbs are kicking my butt!! iv got the 22 vm carbs on my 79 550 the pilot fuel screws are set to one turn out and top air screws are 3/4 out and im STILL rich.. i guess my first question is the top adjustment screw is the air fuel ratio right? well iv been adjusting like in is to lean out and out is to richen am i correct?? it seems to not be affecting my mixture this way sorry for the elementry question but i need a foundation to build off of .... thanks guys

Try 1-3/4 turns out on the air screw, lets more air in which leans the idle mixture. My 550 runs perfectly with the screws adjusted like that.

[richardgrhett]

yeah i got them to start leaning out... at 1 3/4, but now the bike runs like crap no low end to mid power what so ever.. im running pods with stock exhaust.. iv changed my main jets from 80 to 90 and now i guess i should change my needle position down a notch i just don't know what else to do.... Pilot jets need to be changed?

[Nessism]

Oops, didn’t realize you had modified the bike. You might want to do some plug chops in the different throttle position zones to make sure you are not misinterpreting the reason for the flat spot you are experiencing.

[richardgrhett]

yeah.... well i went on and moved my needle up one notch and that actually helped alot.. did an eye ball sync and set the air screws to 1 3/4 and it ran great (still idles rough though, which could be because my battery is completely shot).. three of my cylinders are lookin much better, however one is still too lean for my taste... i guess im on the right path just have to keep tweaking:?. thanks for your help Nessism, ha EVENTUALLY im goin to get this beast right!

[tkent02]

EVENTUALLY im goin to get this beast right!

Doubtful without a true synch and at least a working knowledge of which carburetor screw does what at which throttle position.

On a VM the airscrew does nothing except at idle.

Just get a bigger hammer.

[richardgrhett]

if the air mixture screw only adjusts at idle then what controls its mixture at other levels? (other than the obvious jets and needle)

[duaneage]

The obvious jets and needles.

As soon as your off the idle circuits it depends on the mechanical nature of the needles to enrich as the throttle is opened.