Mixture screw?!?

[geniusloerts]

I just took apart my carbs to clean them and put them back together. I recorded how many turns in the screws were so i could put them back at about the same settings. after getting everything back together and on the bike and now it starts but runs bad, if i give it gas it will die........on a side not question, what are the mixture screw tips suspose to look like?

[bikerphil]

mixture screw

On the 79 carbs, sharp pointy tips. Check your plugs. Black, turn screws in. White, turn screws out.

[geniusloerts]

HELP

ok so i pulled the carbs back off because i had an after thougt....i busted the tips of the mixture screws off......somebody take me out back and shoot me please....... when i turned the screws in i went until the spring was compressed, aparently toooooooo far and tips broke off in the pin hole and now are stuck in there.....

Any suggestions on how to remove the broken tips?

Help.

[bikerphil]

not good but fixable

Read the thread "broken idle mix screw" by Toolmaker Tim. Should be back a page from here.

[geniusloerts]

so i tryed pushing them out before reading all the tech tips, and i ended up bending the needle parts of the tips making things harder. today after work i will get them out!.

[geniusloerts]

does any one know where i can get new mixture screws.....?

[bikerphil]

sources

I got my replacement screws at bikebandit.com, but try Mikesxs.com first, as probably much cheaper. Good luck!

[John]

If all else fails, try motorcyclecarbs.com. He stocks the OEM needles. I bought mine from him.

[Incubus]

Yamaha still has the needles, but be prepared to take out a second mortgage.

Patrick

[geniusloerts]

CARBS

ok so i am looking for another set of carbs since i have messed up these mine.........what is the diffrence between the 79SF carbs and the 82XJ??????

[TopCatGr58]

Slightly less adjustability, only 1 set of "T" fittings, the vent is incorporated into the inlet bell. The jetting WIL BE DIFFERENT due to the difference in the carbs, don't try using the 79's jets! With your mods you may need to rejet the mains, stock IIRC is 112.5's, with 4-1 pipes and Indy filters, you may need ~117.5 to 120. The pilot jet may be okay, and may just need some adjustments of the Pilot screws to tune a little richer for the pilot circuit. The Choke/fuel enrichener is cable activated at the handlebar vs. on the carbs. Otherwise, fairly plug and play.

Sorry to hear about the bunged up pilot screws on your 79 carbs.

Wish more folks would read the tech tips before attempting processes on their bikes, would save them time and $$!
T.C.

[geniusloerts]

TC,
ok so in my XS carbs i was running 147.5 mains and 45 pilots


the XJ carbs had 112.5 mains and it says on the pilots jets 147.5!?!?

if i have them placed right...the pilots are the ones inside the tube and the mains at the end of the side needle......right....

so it seems i need to spend some more green on jets...and i might as well change out all the mixture screws on this carb set since 2 of are striping

[81xsproject]

Do your self a favor and stick with 70's carbs. You can get the screws at Yamaha Sports Center for a decent price. I think there are a few tech tips about removing the broken needles.

And now you have learned the very important lesson that the area known as "lightly seated" is very dangerous territory. Even if you hadn't broken off the tips, the needles and the holes would have been smashed. This make tuning a lot more work.

[geniusloerts]

hey 81,

sorry you didnt catch the other tread.....

this one


but the 70's are messed up

[TopCatGr58]

Hey Genius,

The pilots will be 47.5, not 147.5!! And the mains are smaller because they don't have to share with the pilot, they get their supply directly from the bowl, not thru the main, so that's why the mains are much smaller,ie. 112.5's. SO following the jetting guide for your mods, about 2-3 sizes up from the Stock XJ carbs size is what you'll be looking for, not anything near the old XS 147's!!!!
T.C.