air and fuel mixture screws - 79 1000E

[badfish]

Hello again! Just curious if any of you can enlighten me on the air and fuel mixture screws. After reading BassCliffs carb tutorial, it states there is no factory setting for these. My carbs have the indents next to these screws (both air and fuel). However I couldn't go by where they were set before teardown because the PO had each one set different. They are all currently set at 3/4 of a turn out (and thats what BassCliff said for stock exhaust and airbox).

I don't have the stock exhaust or airbox. I'm more interested in getting the fuel screws set first. After that I can adjust the airs per RPM increase method.

If it helps any, 112.5 mains. Needle in the 4th groove from top, 15 pilots. Currently no air filters but plans are pods. (let the heckling begin!)

Any recommendations on a start point on how many turns out for the fuels?

[tom203]

badfish said......"I don't have the stock exhaust or airbox. I'm more interested in getting the fuel screws set first. "

What do you have??????

[Steve]

He said he "plans on pods", but we will need to know if he plans for the cheap ones or the good ones.


We also need to know if he will be running the exhaust straight out the ports , putting on some short header pipes ,
installing a 4-into-1 header with no muffler , a 4-into-1 header with a race "muffler"
or a 4-into-1 header with a muffler that actually sounds good.


Yes, badfish, all of this information is necessary to give you an educated guess what might work for your bike.
Reading your spark plugs will be the ultimate authority, we can only suggest a starting point.

.

[trippivot]

each one will be set differently -- as each cylinder has an individual balance required . so don't get fixated on exact and equal settings.

start 0.5 fuels and 1.0 airs -or was it the other way around?? lol !! no seriously it is a balancing act but you have to have the air screw out a little more so to create the vacuum needed to pull the gas up thru the carb into the venturi -- you can not get good results by setting the airs in tighter than 0.25 to get a super rich setting

probably going to need some #17.5 pilots -- 20s' may work better due to the combination of filter and exhaust. -- but your spark plug color will be your guide.

bump main up to 117.5 or 120 also

set pilot circuit - then the main and needle last -- save yourself some time

[badfish]

Sorry about the lack of info. Correct, no filters right now. The pipe is some kind of 4-into-1 with a quiet silencer.

[BassCliff]

Hi,

The recommended start point for air/fuel screw settings for the VM carbs are about 3/4 - 7/8 turn for the fuel screw and 1.5 - 1.75 turns for the air screw.

You should decide what kind of air filter(s) you are going to use and put them on before you start jetting the carbs.

ANY changes to intake or exhaust requires re-jetting. If you jet for no air filters at all, and then put an air filter on, you will have to re-jet again.

Please forgive my profound glimpse into the obvious.


Thank you for your indulgence,

BassCliff

[badfish]

Thanks, it helps. What I got going on is I picked this bike up for cheap.....Like $100 cheap. It was missing the battery, airbox, and the starter clutch was torn apart (however all there). I put the starter clutch back together, drained and filled and redrained the oil. Ordered an o-ring set for the carbs and the intake boots. Cleaned carbs and installed new o-rings. I'm currently working without a battery (I'm jumping it off my car, not running) just to see where I stand with how the bike will run. I don't have the cash to toss away at a battery at the moment. I'm trying to spend as little as possible until I know the bike is worthy of sticking more money into it. No sense dumping a bunch of money into it if its not going to be a usable machine.

The bike will idle fine both with the choke on and off but once you give it some throttle it instantly dies. This is with the 4-into-1 exhaust and no filters. Again, I'll go with pods once I can get it to where it runs (for the most part) right.

I do appreciate all the help I can get from you guys.

[BassCliff]

Hi,

The bike will idle fine both with the choke on and off but once you give it some throttle it instantly dies.

This is normal behavior for a GS with no air filter. It's running waaay to lean.


Thank you for your indulgence,

BassCliff

[rustybronco]

And his main jets are WAY to small.

[chuck hahn]

It needs some restriction..so throw a Tshirt across the carb throats.

[badfish]

Thanks. This points me in the right direction.

Also...the 3-into-1 vacuum tubes coming off the carbs, should that be capped off while I'm using a small test tank?