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JFairman JFairman is offline
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Join Date: Jul 2006
Location: S. Florida
Posts: 7,273
If the screws are real tight and it seems like the screwdriver slots are going to distort and slip than try PB blaster and gentle use of an impact wrench with flatblade screw bit installed and light taps with a hammer to get them loose.

The 930 fuel heads have 4mm round head allen head bolts there instead of flat blade screw slots.

With them out you'll see 3mm allen head adjustments underneath. They are the spring tension adjustments.
Turn them clockwise a little bit at a time to put more pressure on the diaphram to push it down and let more fuel pass by the small clearance between the top side of the diaphram and the bottom of the orifice thats below the fuel injector line banjo bolt.

Your fuel head looks like an older cast iron one with a stainless steel diaphram in between the top half and lower half of the fuel head so if you go too far with those spring tension adjustments you may dent the diaphram and then it will need to be replaced to meter fuel correctly.

The aluminum USA fuel heads use a white colored synthetic diaphram material that is more flexible than the older stainless steel diaphrams used in the cast iron fuel heads.
From what I've heard... this more flexible diaphram is why the lighter cast aluminum lambda fuel heads can be modified to flow more fuel than the older cast iron fuel heads with their stiffer stainless steel diaphram.
Old 02-09-2010, 09:50 AM
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