RE-JETTING AND EXHAUST GS1100L '80

[Anonymous]

I POSTED NOT LONG AGO AND GOT A FEW ANSWERS... THANKS TO ALL OF YOU WHO'VE HELPED.

MY OBJECTIVE IS TO GIVE MY BIKE A LITTLE BOOST IN PERFORMANCE AND TO GIVE IT A DEEP SOUND. TRUTH BE TOLD I JUST WANT TO DO IT FOR THE SAKE OF A PROJECT.

I'M PLANNING TO GO AHEAD WITH MY PROJECT OF INCREASING JET SIZE (HEARD THAT REPLACING 107.5 MAIN JET WITH 112.5 JET WOULD ABOUT GET ME WHERE I WANT TO BE IF I RUN RIGHT OFF THE 2 INT ONE CROSSOVER ON EITHER SIDE OR JUST DRILL HOLES THROUGH THE REAR OF THE BAFFLES) IN ADDITION I WAS GOING TO PUT ON CHEAPO EMGO POD FILTERS TO REPLACE THE STOCK AIRBOX. QUESTION IS WILL I ALSO NEED TO REPLACE NEEDLE JETS AND PILOT JETS?
ALSO WILL I NEED TO CHANGE OR MOVE NEEDLE?
THIS SEEMS EASIER TO DO THAN USING A K&N JET KIT I HEARD ABOUT ON THIS FORUM FROM K&N.
BRINGS ME TO ANOTHER QUESTION HOW HARD IS IT TO INSTALL THE KIT AND DO ALL COMPONENTS NEED TO BE USED FOR IT TO WORK? I FEEL REAL UNCOMFORTABLE ABOUT ANY DRILLING.

HAS ANYONE EVER GONE THIS ROUTE AND HOW'D IT WORK? WHAT JETS DID YOU USE?

THANKS IN ADVANCE. THIS FORUM HAS BEEN A REAL ASSET.

FRED

 

[KEITH KRAUSE]

I'm not sure what you mean about drilling holes in baffles, I just know I would'nt.
Pod air filters WILL require larger mains, raising the jet-needles and possibly larger pilot jets or at least pilot/fuel screw adjustments.
Going from a 107.5 to a 112.5 main is not enough to allow for pod's increase in air intake flow. More like 4 full sizes up(127.5) is where I would start if these emgo pods suck air like K/N's. If your CV carbs needles adjust like my VM's, you will need to lower the e-clip about 2 grooves. This will raise the needle up 2 positions. Whatever mixture/fuel screws you have will need to be adjusted richer, or you may have to go up a 1/2 size or full size on the pilots. These are just starting point suggestions. Test and get plug reads. Do what the plugs tell you to do.

 

[first timer]

i would personally go with a k and n jet kit. figure this much, someone has already done the calculations for you on what works with your bike. i hope they have a kit for your bike, and for 45 bucks they are a steal. they are pretty easy to install to and if you have questions on how to do it just ask here.

i have a question about having to re syncing your carbs if you raise or lower you needles. does this only apply to vm carbs or cv carbs? and what if you only lower your needles one step. could you please explain the reasoning behind re syncing after needle adjustment. at lest on the cv carbs you are adjusting a butter fly valve that controls the air flow you are not adjusting the needle to keep the motor in sync.

i'm only asking because i just droped my needles down a notch and the bike seems to run as good if not better then before, and i never re synced. i also find it easier to type then to re synce. i have cv type carbs on my bike.

ryan

 

[KEITH KRAUSE]

On VM carbs, you must take out the slides to adjust the needle e-clip position. This disturbs any previous synching.
I'm not very familiar with the CV carbs and I try to let the person asking for help know this. I was going to post a topic asking about CV jetting because I would like to learn more so I can help others. I just got a hold of some brief info about CV carbs. The info is for the first year these carbs were used on GS's, 1980. It says the needle position is not adjustable, but you say you lowered your needles 1 notch. Since yours is an '81, did the needle become adjustable after the first year?
I know the CV carbs need synching after disassembly, but you say yours runs fine without synching? It appears the throttle valve plates are adjusted uniformly to achieve this. As for adjusting the needles to keep the motor in synch, as you said, I think you misunderstood me. I know the needle is used for jetting, the slides(VM) and throttle valve plates(CV) are what you must synch.
I have 1 more question. You say you lowered the needle 1 notch. Why? What intake/exhaust mod's do you have? Normally, you have to richen the mixture by RAISING the needle to allow for an increase in air intake. Did you install a jet kit that does allow needle adjustment?
I'm a little unclear what you have. Can I get more info?
PS: In my first reply, I edited out the sentence about having to re-synch if the needles are disturbed. I now realize the CV carbs don't require this because of their design.