Pilot screw turns?

[MrZig]

I'm wondering how many turns out the pilot screw should be on my 1980 GSX400's carbs? I think they're the same carbs as the ones on the 1982-1983 GS450.

I believe they are BS32SS.

I ask this because I finally got mine running (passed the skills test too!) and took it out on the street a bit. It sounded like it was surging a bit when cruising around 60 KPH. I brought it home and looked at the plugs and they were both white. Oof, gonna burn a valve if I keep running it like that.. Also I just installed new intake o-rings so it can't be that.

When I set the screws, I bottomed them out and unscrewed each by 1.5 turns. Is that right, or should it start at 2, or 2.5?

I also just got new pilot screw o-rings today so I'm going to install those and try the highest-rpm method, however I would still like to know what to start at.

Also when unscrewing the screw, am I enrichening it or leaning it?

[Nessism]

My vote is 2.5 turns to start.

[MrZig]

Okay, but still, does screwing it out enrichen it? IE 3 turns would be rich, 1 turn would be lean?

[Nessism]

Okay, but still, does screwing it out enrichen it? IE 3 turns would be rich, 1 turn would be lean?

Yes!

[MrZig]

Awesome, thanks.

[donimo]

my haynes gsx400 book says 1.25-1.75, and 1.5 to start. the carbs are a tad different, smaller intakes too so it doesnt surprise me they are tuned different too.

[nisom512]

the spec settings for your carbs in here http://www.thegsresources.com/_forum...ad.php?t=73723

[donimo]

strange I read some more and the gsx400 "EX" is the 1.5 turns, and the "EZ" is 2.0 turns.

Also they are BS34SS canbs, not 32's

[MrZig]

strange I read some more and the gsx400 "EX" is the 1.5 turns, and the "EZ" is 2.0 turns.

Also they are BS34SS canbs, not 32's

Positive on the BS34SS? hm okay. Well I'll start at 1.5 and turn it out until I get the maximum RPM.

[donimo]

Well, positive as I can be

Book says 34's

Mine runs at 1.5, but I havent tuned squat yet...

[Nessism]

1.5 turns is killer lean. The 450 is famous for being lean, not sure about the four valve 400 though.

[donimo]

the book DOES state 2 different specs for the "x" or "z" versions (I think that is 1981 and 1983 models.

81 is 1.5 turns, 83 is 2 turns, not sure why though, same motor, same carbs...