Saturday, February 4, 2017

Tune Up Time

It has been a few thousand miles and I have noticed that Ole Blue has been coughing a little when I accelerate out of turns on the country roads heading to the beach. I think I need to take another look at the carburetor. So, this morning 'Choke Boy' and I took a drive down the highway a couple of miles and then, with a warm engine, went to work by hooking up the vacuum gauge and timing light.

My plan was to:
  1. Note the idle vacuum reading. Normal vacuum at idle should be 19-21 inches for a six cylinder, or 15-18 inches on a low compression engine. 
  2. Check the ignition timing, before making any carb adjustments.
  3. Lean out the mixture screws (turn in).  
  4. After each adjustment is made, reset the idle speed.
I had also picked up a tachometer / dwell meter at goodwill for $1 and I hooked it up as well. The tachometer was reading 800 rpm, the vacuum was at 19 inches and the timing was a bit advanced of my white mark from last year, so I released the lock down bolt and reset the timing to 10 degrees BTDC.

I checked the idle mixture screws. Turning each screw about 1/2 turn in, I was thinking I needed to lean out the carb a little to reduce the coughing. The vacuum was still reading 19 inches so I turned it 1/4 turn more and rechecked the idle speed, setting it at 700.

I cranked down on the distributor hold down bolt, disconnected the meters and took her for a test drive, Choke Boy riding shotgun. She pulled away smooth from full stops and as we headed out of town on the little two lane road west we easily cruised at 55 out to the turns in the road as it meanders through the low hills. Entering the first turn I let up on the accelerator and when I pushed down to accelerate out of the turn Old Blue jumped without any hesitation, pulling us through the corner, accelerating into the straights. Yeah, Baby let's drive this a while and see how it feels!