Carb jetting

[dbwill]

I have the carbs torn down and would like to change the jets which are 115 , 120) which I think are stock? I have a header (4 into 2) and plan to have air box Mods or intake pods. What jets are other's running Thanks Den

[DiverRay]

I would need more information on your bike. Year, Model come to mind, as the '78 and '79 carbs are DIFFERENT than the later models.

[dbwill]

jets

1980 xs 1100g

[tarzan]

Is it running lean now?Maybe do your mods and install your carbs then sync and adjust idle mixyures.Then if it runs lean start thinking about jets.A lot of guys on here have chased their tails for a while because they just knew they needed bigger jets only to find out they needed to go back to stock or close to it.

[bikerphil]

jetting recommendations

Here's the link to the jetting recommendations..... HTH

http://www.xs11.com/forum/showthread...=&threadid=382

[TopCatGr58]

Hey there DBWill,

Like Tarzan stated, you may not need to rejet!? I have an 81SH, and it came with 110's straight across stock!! Yamaha kept jetting them leaner in the later years for Emissions Standards!

I put 4-1 pipes on mine shortly after I got it back to the US from Japan, was stationed there, and ran it that way with stock Airbox for 8 years, never burned a piston, and could take it to redline without problems!

Only after I did a topend little big bore kit and put Indy Pod filters on did I rejet, took it to 117.5 across all 4, kept stock Pilot jets, good plug color, plenty of power to redline, was just a slight drop on the DYNO chart at the pilot to mains transition rpm of 3500, so could have gone up a size on the mains to 120.

So...you could save some $$, and just get 2 more 120's, forget about the staggered jetting...was a gimick to try to keep the inner 2 cylinders a little cooler than the outer two with richer mixtures....Yamaha abandoned that with the later year models anyways!
T.C.

[XSPastor]

TopCat knows his stuff. I run 120 mains all across in my SH with a 4 to1 Jardine and a drilled stock airbox with a K&N. Runs GREAT!

[TADracer]

Since your 4-2 exhaust is not so far from stock and you still have the stock airbox I would clean everything up and try the jets you have first then read your plugs. If they have a nice coloUr then keep your current jetting. Air in and exhaust out dictate your carb setup. Alot of people go for the carbs first when they should be the last thing you adjust.

Ps. I added the U in the word color after reading another thread on the forum today.