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Hi Dave, ----- Original Message ----- From: "Dave Hall" <dave@hallvw.clara.co.uk> > The 1600 info taken from a contemporary brochure gives cruising consumption as > 34mpg (imp), and that is indeed what my 71 Variant has always done on a journey > at speeds around 60mph, even full of camping gear. Maybe it is time to measure > the displacement (somehow!). > > Something is over-fuelling the engine if it's persistently running rich, and > you've had the heads off so you would have noticed damaged valves etc. > Have the carbs still got stock main jets? (unlikely there's a problem here if > the other carbs have behaved the same). Well it hasn't always run rich. I used to run it at about 3 1/2 turns out and the plugs were pretty clean and lean looking. However still the lousy mileage. Now I run it rich (at idle anyway) and am getting smoother running and better consumption. The carbs had the stock jets until today when I fitted 135 to the left (with 150 air correction) and 132.5 right with 140 air (I didn't have a matching pair and according to Haynes it was typical until the 70's to run the left carb richer than the right- presumably for cooler running.) However, first impressions are that it didn't change a thing ;-( I'm getting fairly good compression test readings so I don't think it can be valves but who knows? I guess I must have an air leak- I still needed to set the idle screw out about 5 turns to get satisfactory idling. Tomorrow I will fit the NOS throttle plates I have (which incidentally all have the PTFE and brass inserts already fitted as do all my carbs so I think they must be stock!) and see if that makes a difference to the idle adjustment. At present I am using plates that I re-bushed myself with Iglidur bushes and I'm thinking that maybe they aren't good enough :-( I have good thick papery gaskets between the heads and manifolds and the others are fresh so I can't think where else I might have a leak. And its strange to me that both carbs are settling on about the same happy settings- that points to the bushings doesn't it!- they are the only common dubious thing. > How do you estimate consumption - running total of miles and gallons over some > months/2000 miles eg? I always fill to brim full and note the mileage at fill up so I know how much I used and use an excel spread sheet to work it out. > 22mpg (imp) on fairly short urban journeys may not be excessive; a drop of 10% > to 20% isn't that unusual, as the published urban and cruising mpgs quoted in > brochures for modern cars show. Maybe I should just stop worrying- its just that even on longer journeys I don't get near the VW quoted mileage that you seem to get. I'm just worried that something is wrong that I could fix and save me some money! ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ List info at http://www.vwtype3.org/list | mailto:gregm@vwtype3.org