I had a plan going in to Sunday morning, after sitting back and thinking about all of the symptoms I’ve been facing with the carburetor. Typically when i’m working on mechanical or computer problems I’ll diagnose things backwards until I get to something I know is working. Then I move forward until I’ve identified the fault. On the carburetor, I knew that the engine spark timing was off, and the only good way I know to adjust that is to loosen the distributor while the engine is running and spin it slowly until the idle smooths out.
I figured the best way to do this was to put the old Holley 2300 back on the engine and work through the problem mechanically. Unbolting the Sniper from the engine, I put it aside, resting on some cardboard, and disconnected all of the wiring. I pulled the old carb from one of my spares bins and swapped it onto the engine, plumbing it to the boat tank through an electric fuel pump. With a couple squirts of 50-1 gas in the throat, the engine fired right up but sounded very choppy and died off after about 10 seconds. I got a couple of backfires out the throat of the carb—a sure sign of bad timing.
After verifying this was consistent behavior, I got it running long enough to get out to the distributor and slowly twist until the idle smoothed out and the throttle picked up. Then I tightened the mixture screws (they were wide open from last fall, when I was battling the dead condenser thinking it was a fuel issue) and adjusted the throttle until it was idling happily by itself.
Relieved, I let it run for about 10 minutes and shut it down, figuring it was warmed up enough to give the Sniper a hand. The learning feature in the Sniper control unit kicks in after the engine is warmed up past 160˚, and that was what I was shooting for: I wanted it to learn how to adjust the fuel/air mixture and self-meter. Friday evening I’d pulled the water neck open and examined the thermostat that was in the engine. I figured I’d find something crustier than a wino’s beard but the passages and thermostat looked almost brand-new, which was a pleasant surprise. I put a new 180˚ unit in and closed it back up.
I hustled around the engine and got the Sniper back in place in about 10 minutes, verifying I had reconnected the electric leads to everything, said a Hail Mary, and fired it off. It started immediately, and ran a lot smoother than it originally did—but was still hunting for the right fuel/air ratio, surging and fading. I let it run for a couple of minutes, noting that the temperature was reading 178˚ but knowing that the radiator wasn’t full, and shut it down after watching the Learn setting on the control unit struggle to balance things out.
I tried to restart after a couple of minutes but the battery sounded tired, so I hooked the tender back up and let it cool down. The Sniper says it’s reading 14 volts when the engine surges, but I’d bet the alternator is dead so I’ll source a new one after I verify its condition.
So: I know that the timing on the engine is set more correctly than it had been. I know that the Sniper will start the engine and run more consistently than it had been. I know I probably need to adjust the timing settings in the control unit again to better match the engine, and I know that the water passages are clean—but need more coolant.
With a little more time to kill, I got my 3M automotive tape out and finally put the International badge on the rear door. Looking at the rear quarter, I decided I wanted to add the Travelall badge that belonged there too. With the taillight removed I was able to see where the bondo had filled up the original mounting holes and used a chisel to carefully scrape it away to where I could see them. Then I drilled them out and widened them until the posts on the badge fit the holes perfectly. With some more tape the badge went on easily, and now the truck looks even more legit than before.