Arnold
Well-known member
I have this Cen Tech automotive multimeter I bought at Harbor Freight, and I decided to measure the exhaust header temperatures while my 81 Interstate was idling (or trying to idle) last night. I got 240 degrees on cylinders 1 & 2, but only 140 degrees on cylinders 3 & 4. I put a strobe light on all four spark wires sequentially, and all four flashed the same, so I know I have plenty of spark. My carbs must have clogged idle jets, again.
Today I took off the carbs (much faster than last time). I found some rusty material in float bowls. This time I took off the fuel filter and noticed it was full of dark material. I am going to drain and clean the gas tank tomorrow (I'm on vacation this week).
I noticed the idle jet tower had a corner chipped off it and wondered whether that made a difference in the carb's ability to suck gas out of the float bowl. By idle jet tower, I am referring to the appearance of the three cast tubes that project into the float bowl from above. When you turn the carburetor upside down, they look like towers on a castle. The main jet is the tallest with the brass fixtures on top. The very next one is the idle jet tower with the idle jet recessed within. The third tower goes nowhere.
I don't know whether the tip of the idle jet tower must be immersed in gasoline in order to draw the gas through the jet and into the carb. Is it possible that having a chip off the corner (about 1/4 inch diagonal nicked off) is like having a hole in a straw, thus no suction? Someone must have dropped this carb while working on it, and that's when the chip occurred? Any advice?
Today I took off the carbs (much faster than last time). I found some rusty material in float bowls. This time I took off the fuel filter and noticed it was full of dark material. I am going to drain and clean the gas tank tomorrow (I'm on vacation this week).
I noticed the idle jet tower had a corner chipped off it and wondered whether that made a difference in the carb's ability to suck gas out of the float bowl. By idle jet tower, I am referring to the appearance of the three cast tubes that project into the float bowl from above. When you turn the carburetor upside down, they look like towers on a castle. The main jet is the tallest with the brass fixtures on top. The very next one is the idle jet tower with the idle jet recessed within. The third tower goes nowhere.
I don't know whether the tip of the idle jet tower must be immersed in gasoline in order to draw the gas through the jet and into the carb. Is it possible that having a chip off the corner (about 1/4 inch diagonal nicked off) is like having a hole in a straw, thus no suction? Someone must have dropped this carb while working on it, and that's when the chip occurred? Any advice?