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These look just a little sooty, rich. what is the compression on this engine, if the compression too high you will also have a heat problem, with that big engine you should be around 7.3to7.5:1 C/R the higher the compression the hotter it will run. You may have to add some spacers under the cylinders to get it down. Phil --- David Y <goob@adelphia.net> wrote: > 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! > > > > ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ > List info at http://www.vwtype3.org/list | > mailto:gregm@vwtype3.org > ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ > > __________________________________ Yahoo! Mail - PC Magazine Editors' Choice 2005 http://mail.yahoo.com