I started my 235 up for the first time on Saturday. It is a 59 truck engine bored .060, fresh ground crank, rebuilt 848 head. Dual Fenton exhaust and Intake. I bought two Weber 32/36 from Tom Langdon. It has HEI ignition. It started up fairly easily and ran smooth. I adjusted the timing to 12 degrees advanced at 500 rpm. It was retarded at first, but I corrected that once I got my timing light on it. I set the idle mixture screw after turning it in and the engine struggled, and I gave it 1/4 turn out on both carbs. Looking at YouTube videos on tuning these carbs I have a few questions. So far, I like the versatility of these carbs and their ability to tune more precisely. I liken them to a VM Mikuni on a snowmobile. I'm good at those. My questions are, The idle mixing screws are at 1 turn and the primary venturi jets are 75. Too big, Too rich? I need smaller primary jets. How small? SECOND question is the secondary venturi jet is 60. Too small? Too lean? I'm getting a sputter/backfire when I get into the secondaries. It does not happen when not loaded, just when driving. I've tried different timing but its not a fix. I even tried to not have vacuum advance as the HEI does not require that I use the vacuum advance supposedly. Without the advance I get about 25 degrees at 2500 rpm. With the vacuum advance I get 45degrees at 2500. Both start at 12-15 degrees at idle. I'm thinking the jets are too small on the secondaries and I am lean, causing the backfire.
