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General Category => Maintenance => Topic started by: bigbore2 on May 12, 2015, 07:29:45 PM

Title: adjusting screw on carbs
Post by: bigbore2 on May 12, 2015, 07:29:45 PM
84 1100 with the Mikuni carbs where the pilot jet adjustment is on top of the carb looking straight down from above with tank off.  OK, I'm not really adjusting the pilot jet, but the pilot jet range.

turn in is leaner, out is richer?
Title: Re: adjusting screw on carbs
Post by: Capn Ron on May 12, 2015, 08:00:59 PM
BigBore,

I had this same question a while back and documents and opinions were offered up that basically contradict each other.  Wish I could answer that for you, but I'm still shrugging my shoulders.   :unknown:

I'll be watching this thread in case it does get answered.   :good2:
Title: Re: adjusting screw on carbs
Post by: Flying Scotsman on May 12, 2015, 08:11:53 PM
Brass screws are for the air fuel mixture.
If you turn them in you get less fuel and air not just less fuel.
Title: Re: adjusting screw on carbs
Post by: bigbore2 on May 12, 2015, 08:19:22 PM
yes those brass screws. I know it meters both, but the adjustment is still there.

So in simplest terms, is it turn out to lean or turn out to richen??
Title: Re: adjusting screw on carbs
Post by: turbocamino on May 12, 2015, 08:28:35 PM
  turning down= leaner....if you have removed the airbox,try 3 turns out from lightly seated (closed) most all end up around there.
Title: Re: adjusting screw on carbs
Post by: bigbore2 on May 12, 2015, 08:34:03 PM
yes Turbocamino- out is richer, in is leaner.

My bike WANTS more fuel, had to up the main 3 sizes, I think and add washers to the needles.  I have gone up in the pilot too and am not there yet. And I am at 5000 ft. Go figure.
Uni pods and 4/1 Yosh exhaust.

A nice write-up can be found in the files section under carburetor files.  I actually looked it up. Pat and Randy contributing.
Title: Re: adjusting screw on carbs
Post by: Flying Scotsman on May 12, 2015, 08:56:30 PM
Tip of the screw protrudes into the throat of the carb so its always drawing air as long as its not closed.Pilot jet is not adjustable without changing to a different size. 
Title: Re: adjusting screw on carbs
Post by: FJ_Hooligan on May 13, 2015, 08:06:04 PM
Bottomline is it doesn't really matter. Screw them in at half turn increments until the blip test starts to degrade. Then screw them out in half turns until it degrades. Back in a half turn and you're done