In Reply to: 51 8N Spittin & Sputterin posted by Steve in MO on July 22, 2018 at 03:42:35:
Welcome to the wonderful world of Vintage FORD N-Series Tractors -you're gonna have fun! You gave us a very thorough list of many crucial items and what you did. You don't have to go to YTMAG -we have a ton of free info in our HOW-TO's forum, including Don Stewarts carb overhaul. Your carb issues might be solved by understanding how the N engines work. With the updraft fuel system on the carb after rebuild, make initial settings -MAIN JET OUT 1-1/2 turns and leave it. The throttle plate idle screw is set at rebuild 1-1/4 turns off stop post, or so it is just starting to open plate, and leave it. Next, adjust side pointing idle air mix screw to fastest idle, not the smoothest, and start at 1 turn out from full set seat. Note that OUT is for LEAN and IN is for RICH. The key to this is to first; perform when engine is up to operating hot temperature so run it for at least 15 minutes before making any adjustments. Secondly, adjustments arenít done simply by turning one or the other screws once and leaving it. It usually takes 2, 3, or more tries to get it right, with at least 15 minutes between tests. Note where each screw setting is before making a turn and then only go 1/8 of a turn at a time. Adjust a screw, then WAIT! It will take the engine a few seconds or longer for speed to catch up. Since you have a later 8N, you can use your Proofmeter to identify engine RPMSs exactly. Adjust the throttle Ėbehind the carb idle screw for very slow RPMs, 400 is spec. Adjust air idle screw until RPM increases. Then adjust throttle screw to 400 RPMs or til engine almost stops. You can take hold of the rod between carb and gov and shake it and slightly twist it so it isnít being hung and prevents the adjustment cam from moving. Iíd hold of on removing the governor for now, it may be fine, but no need to introduce another factor in the equation until you know for sure. Next, you say you dia 12V switch over job. Thatís fine, but was it done correctly? Check out WIRING PICTOGRAMS by JMORĒ in our HOW-TOíS/ELECTRICAL see LINK below. Download a copy and keep it handy. Verify your wiring matches one of the set ups JMOR documented. 99.98% of non-starting/non-running/poor running issues are due to incorrect wiring jobs whether 6V/POS GRN or 12V/NEG GRN. Many supposed fuel issues often are electrical issues vice versa. You donít go into your electrical at all so check it out completely Ėno deviations from the pictograms allowed.