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Fine tuning Standard Kombi Carbs
Kommer - April 18th, 2005 at 02:03 PM

I have standard carbs on my 2.0l aircooled, and have just fitted tuned length "hotdog" style extractors. The car now performs better overall, but tends to be a bit uneven when accelerating through at medium revs and at about 1/4 to 1/3 or 1/2 throttle opening.

I have read about the possible need to re-jet, but when I pulled the carbs apart the only jet that I could find that was removable was the main jet (apart from the air jet at the top of the carb near the choke butterfly). Is it the main that needs to be changed ? I thought that the main was for 3/4 to full throttle range- or have I been messing about with motorbike carbs for too long ? Do extractors generally need a bigger or a smaller jet ? I've read David Schwartz's article at http://www.type2.com/  and it hasn't helped too much. There are lots of Kombis around with extractors on: do they generally need re-jetting ? Which way- richer or leaner ?
Thanks for your help.
Kom


toplessbug - April 18th, 2005 at 09:15 PM

you can open up the idle jet a poofteenth ,thats a touch more than a flyshit, and you should find a fair difference its prolly a 45 so go to a 50 or to put another way go up 1 jet size .the idle jet is in the bottom of the idle cut off solenoid on the side of the carbys


Kommer - April 19th, 2005 at 01:13 PM

Thanks Topless,
I had a look at one of the cut-off solenoids (I presume you don't mean the one for the central idling system) and it has a little brass doo-dad thingo pressed onto the end of it. Is that the idle jet ? Mine doesn't have any kind of a number written on it like 45 or 50. Nothjng at all in fact. Are you suggesting I drill it out, or are alternate sizes available ?
Ta,
Kommer


vw54 - April 19th, 2005 at 01:21 PM

where are you located ??


Kommer - April 19th, 2005 at 02:14 PM

Blue Mountains, Springwood-'ish


toplessbug - April 20th, 2005 at 09:35 AM

the idle solenoids are on the side of the carbs high up on the body and are about 3/4" diameter and have the jet in the end if you have a set of number drills measure what is there now and drill it 1 size bigger were only talking .05mm or .002". imperial number drills you will need are around the 74 --77 mark im not sure what alternatives are available but dave will know or ring vvds


Andy - April 20th, 2005 at 03:06 PM

Might be worth having a play with the accelerator pump also. It was part of the cause of a similar problem on my 2L dual carb.
:blah