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Subject:Vacuum advance problems
Date:21 Nov 94 24:27

Hi All,
     
     (advance apologies if I forgot how to spell VACUUM? )
     
     So I've just run my new bus engine in (1600cc Single port) and
     I figured it was time to go over 40 MPH.
     
     Foot to the floor maximum of 50MPH!
     
     I checked the points - they were way off 0.006 instead of 0.016 due to 
     being bent. Don't know how the hell they got bent, but they're OK now.
     I thought that was the problem - nope still doesn't go over 50 MPH.
     
     When I had the distributor out I tested the vacuum advance by sucking 
     on the vacuum tube and it seemed to work OK - moved the base by upto 
     about 15-20 degrees.
     
     So I decided to measure the vacuum produced by the carb. I stuck a 
     pipe on the little vacuum pipe which sticks out the side of the carb. 
     and attached the vacuum gauge to the end of that pipe. I give the 
     engine a rev and it only managed 4 mmHg on the gauge. I measured my 
     mates (Danny) and his was pulling 15 mm HG so I figured mine was duff.
     The VW technical manual shows that the vacuum should be alot more than
     4!! And yes the carb is certainly sucking in lots of air - I'll show 
     you the ring on the parm of my hand some day - not a smart way of 
     testing how much air the carb is pulling.
     
     Other associated problems might be that I have a Solex 30 Pict-2 
     instead of a 30 or 28 Pict-1, Does anyone know the difference between 
     the Pict-1 and Pict-2 carbs (apart from the float chamber shape). The 
     vacuum arrangement seems to be the same on both.
     
     Do you think the little vacuum tube in the carb might be blocked. I 
     have a 120 compressor so I'm gonna try blasting it tonite.
     
     
     Any comments would be useful,
     
     
     Lee.
     L.S.Griffiths@Physics.Salford.ac.uk
     
     '64 Poorly Samba

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