Re: [T3] plug reading (was engine/carb questions)

["Dave Hall" <dave@hallvw.clara.co.uk>]

Don't you have CO measuring equipment in the USA?  I use a DIY machine, and set
it about 3% CO for the stock carbs.
The ring of carbon on the thread end looks perfectly normal for unleaded fuel;
the electrodes look reasonably OK to me, but as Jim says you've hardly driven it
far enough to be sure of the plug colour.

My feeling on the rapid oil temp increase at highway speeds is that it's
probably nothing to do with the carb mixture, but an air or oil circulation
problem.
The air intake boot isn't collapsing or getting sucked in?  That would cause the
problem easily!

I would be tempted to try the original distributor if all else looks OK.  I
don't really trust the 009, but I've never owned one so it's all second-hand
info.


Dave.
UK VW Type 3 & 4 Club
http://www.hallvw.clara.co.uk/
------
----- Original Message ----- 
From: "David Y" <goob@adelphia.net>
To: "T3 List" <type3@vwtype3.org>
Sent: Wednesday, September 14, 2005 12:32 AM
Subject: [T3] plug reading (was engine/carb questions)


> Can someone "read" the plug below for me? (too lean, too rich?). This is
> with 170 main jets. I was running 140s before, which was obviously very
> lean, and the engine was running hot. [To rehash briefly it's a new 1776
> dual port w/ Berg full-flow, C.W. 69mm crankshaft, stainless steel valves,
> 009 w/ Pertronix, dual Solex H32/34 PDS13, "tuck away" extractor exhaust
> from ISP West)]  The engine rebuilder gave me four sets of main jets to try
> (150, 155, 160, 170) and suggested from the very lean plug and overheating
> that I start with the 170s. I decided to try the 160s first. Engine idled
> perfectly so I didn't adjust anything. Temp was stable at 180-190F around
> town. Then I got on the freeway (65mph/75 degrees outside temp) and within
> 5-6 miles the oil temp was up around 230F+ so once again I had to pull off
> to cool it down. This was an improvement though (it heated up much faster
> with the 140s) so i thought I'd try the 170s. The 170s were a further
> improvement (it took 8 miles on the freeway to overheat @ 230+F this time
> ;) but this is still unacceptable.
>
> So, based on the photos of my #2 plug below (which I do not have the
> experience to decipher) if it is still lean should I try even bigger main
> jets (180s? 200s) or if too rich, should I back the size down and look
> somewhere else for my overheating problem? Looks rich to me, but I'm not
> exactly sure how to read the tea leaves.... TIA!
>
> http://dcr.csusb.edu/dny/170_main_jets-5.jpg
> http://dcr.csusb.edu/dny/170_main_jets-6.jpg
>
> Also, I didn't adjust the idle air or volume air screws after changing the
> main jets, because the idle remained steady and the carbs remained balanced
> at idle (I didn't check the balance at high rpm). Is is necessary to
> readjust the air/fuel mixture after increasing the size of the main jets?
> Thanks again!
>
> Dave Y.
> 68 sqbk
>
> PS I fiddled with my Eudora settings to try to get rid of the HTML text.
> Apologies!
>
>
>
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