carb idle popping fine tuning

[mjpxs11sh]

whats up all! i pulled and cleaned the carbs on my 81 Special. all throttle postitions seem good, no hesitation, seems like all carb circuts good except when 1st started with choke. i get popping thru the carbs a little only when cold. i try to pull the choke off asap, then its better untill it gets warm, then great. carbs are all stock 110 mains 42.5 pilots, needles stock. i have a Kirker 4/1, stock air box, i initally set idle mix screws back to stock setting, 2.5 turns out, then reset .25 richer to see what effect it had. better? not sure but i think so. its not so black and white, ya know what i mean. isnt the popping from a lean condition? how far should/can i turn out the mix screws? im not totally clear on it. thanx

[WMarshy]

Check your plugs to see if any are lean, 1/4 turn might be all you need. Double check you have all the vac ports on the carb boots hooked/capped.

[mjpxs11sh]

yeah, ive had them out several times, and they seem they r burnin a little lean. arent they supposed to be kinda tan? they r more white-ish is the best i can describe them. ill post pix, ill try to get close-ups. i guess that ill help. do u know what they should look like when normal?

[mjpxs11sh]

spark plug pix

here r the pix. #3 is a little black? the rest look the same

[natemoen]

Have you synced the carbs?

[mjpxs11sh]

since i dont have a sync set, i never seperated the carbs. it ran great the last time i had it runnin. thought id get away with just cleaning them together. i suppose ur gonna tell me they need sync'd? i guess that would fine tune em, but ill have to find a friend.

[mjpxs11sh]

BTY dont u sync them to #3? thats the only plug that is carboned, the rest look normal

[TopCatGr58]

Hey MJP,

The Synching process was suggested for trying to address the popping condition, but the black/dark plug is caused by other factors, the synch will not affect it. When you cleaned the carbs, did you ensure that the jet IN the float bowl and the port on the edge of the float bowl were clear and that cleaner could flow thru them? That jet feeds the Choke/enrichener circuit.

Next, your float height may be just enough off on the #3 carb to cause the darker plug..slightly richer than the others.

Also, I can't remember if you posted about any electrical work, but have you removed the spark plug caps and checked the corrosion between the plug wire and cap? If found, trimming back 1/4" inch at a time to get to good copper wire without making the wire too short.

Next, you can try swapping the actual plugs to see if the dark one will clean up, and if another one will darken in the #3 hole?

A tan or light gray appearance of the plug insulator is what you're hoping to see. There's a pictorial guide in the tech tips...I think under maintanence that shows varying plugs and their appearance depending on engine conditions.

T.C.

[mjpxs11sh]

yeah T.C., i blew compressed air and carb cleaner thru the carbs, and new pilots ill recheck mix screw on #3, thats the only adj. i did to richen it up for the popping issue. i may have to get back into carb 3, its light carbon but i think im gonna put some miles on her. its been a long time comin. see should be allright

[mjpxs11sh]

Anyone with colortune/carb sync tools illinois

im financially unable to buy the nec tools for my 81 Specials carb a/f mix adjustment and sync. anybody close to Northeastern Illinois near the Wisconsin border? it would be great if u can assist my Black Beast. she wants to purrrrrrr!

[81xsproject]

Hmmm... I wonder if I should COPY and PASTE my response to your other COPY and PASTE thread...? I like your pics by the way. DAMN you auto focus!!