TRINC! Need Air / Fuel Screw Adjustment Info

[Anonymous]

How do you guys adjust your idle screws?

I have set mine to 2.5 turns out but that's not working.

I looked at FactoryPro's method, but didn't find a good step-by-step method.

Anyone know how to use the 'idle-drop method?

*Everything is stock in the carbs 93 600

[trinc]

adjust them out until you have a smooth idle.
once the bike is up to temp and idle somewhat smooth you can then fine tune it by watching how the needle comes back to idle.

i thought 3 turns was stock.

and nice description: not working. can you expand on that ?

tim

btw - valves out of tolerance & carbs not sync'd will also effect the idle.

[Anonymous]

and nice description: not working. can you expand on that ?.

Sorry, I'm sure it runs lean because the idle take a while to roll down if I blip it from idle...and when I check the plugs, they're bone dry as opposed to some residue left by richness...

The only problem I'm having is that I know the entire system is running lean, but can't narrow it to a certain carb...and right now, I think the screws are so off I can't sync it properly.

I have heard of the idle drop method where you hook up your sync tool when the engine is warm and turn each A/F screw out to increase the revs until it plataeus and drops down..that point is the point you want? Anyways, I'm leary on doing that anyways with the mercury sync tool I have.

[trinc]

ok

sync'ing the carbs is done on the pilot circuit - so the needles & main jet won't come into play.

if they're all dry and the idle hangs before dropping down turn all 4 screws out an equal amount. say a 1/4 turn on each carb - fire it up & see if its better - if the idle drops too low and then comes back up it's to rich. ( which i doubt you could get that because i bet the idle jet is lean for emissions. just don't go past 4 turns from lightly seated.

i took a little screwdriver and cut the handle in half so i could adjust it on the bike. i wasn't going to buy a 90 degree screwdriver. if you're backing the carbs out to adjust them just set them at 3 1/2 .


before i start i would use a little wd-40 and spray it around all the carb boots - choke lever rubber seals etc. to make sure you haven't got a vacuum leak.

when it is running on idle is it steady or does it bounce up & down a few hundred rpm's ?

tim

[Anonymous]

Steady only after a good warm up...then it's real steady. (I eyed the sync plates as best I could before I slapped the carbs on, but will sync once I get the A/F outaway)

Thanks Tim.

[trinc]

if it's steady after warm up, your close - just turn them out a little more & retest. i think a lot of people don't read the plug correctly.

here's a pic of a plug i pulled


this, imo, is what a plug should look like.

tim

[Anonymous]

Ooooo....mine does not look like that. It's all black, but I think maybe that's from trying so many settings.

[md86]

If they're all black , either scrub them off good or change them , as they're not going to be too easy to read if they're already black ! But if they ARE black , that usually means rich somewhere . Idle could be lean , but could be getting too much fuel somewhere else . I had that problem (lean idle , rich everywhere else) .

[trinc]

Ooooo....mine does not look like that. It's all black, but I think maybe that's from trying so many settings.

maybe it's time for a change ? for now i'd just watch what the tach says - & it says lean.

tim

[The CyberPoet]

Two other thoughts:

Not coming down to idle (i.e. - hanging temporarily at 2 or 3k RPM) is often caused by throttle cables just a hair too tight (not quite enough slack) or by dried fuel residues in the carbs (techron will fix it).

Cheers
=-= The CyberPoet

[Anonymous]

ok

sync'ing the carbs is done on the pilot circuit - so the needles & main jet won't come into play.

if they're all dry and the idle hangs before dropping down turn all 4 screws out an equal amount. say a 1/4 turn on each carb - fire it up & see if its better - if the idle drops too low and then comes back up it's to rich. ( which i doubt you could get that because i bet the idle jet is lean for emissions. just don't go past 4 turns from lightly seated.

i took a little screwdriver and cut the handle in half so i could adjust it on the bike. i wasn't going to buy a 90 degree screwdriver. if you're backing the carbs out to adjust them just set them at 3 1/2 .

before i start i would use a little wd-40 and spray it around all the carb boots - choke lever rubber seals etc. to make sure you haven't got a vacuum leak.

when it is running on idle is it steady or does it bounce up & down a few hundred rpm's ?

tim

Forgot to bump this. Tim, you tha man! Thanks...it has GREAT throttle reponse, hangs a tiny bit (so I'll richen it a tiny bit) but altogether runs GREAT!

[Anonymous]

[trinc]

cool - cause it's ride'n weather again !

tim