Since I recently finished installing a Remflex gasket to get rid of my exhaust manifold leak, installed a new donut seal on the exhaust downpipe, installed a new muffler and exhaust setup, and finally installed the original oil-bath air filter in place of the motorcycle style come air filter that's been on my carb since I bought the Grumman, it was time to finally tune my carb.
I used an old rpm/dwell meter I've had laying around forever, and a vacuum gauge I just picked up and got to settings thing right.
Ends up the carb always running a bit lean. It took about a quarter of a turn of fattening it up to get it where it needed to be. Also, my idle RPMs were high at 700. Lowered it down to 500 RPM. Went for a drive and man oh man, what a difference! Much smoother, more power, running a little cooler, even. And with the lower RPM at idle it's easier to put it in gear from a dead stop and, as I release the clutch it's not as jumpy.
The other bit of work I got to do was bend, flare and install a new hard line going from the manifold vacuum to the PCV valve. Just getting to that point was a bit of a challenge because the fittings and tubing sizes are not standard, it seems. Took a while to find the correct sizes.
I also took a heat shielding type of wrap and wrapped the rubber vacuum lines I recently installed that go from the dual action fuel pump/vacuum pump to the wipers.
At this point, after four years of working on the Grumman repairing, replacing and upgrading various systems, with the last 8 months being specifically focused on getting it running right and dependably, I can happily say I've reached that point. I can now turn the key, drive it, and it's running really, really well.
The icing on the cake was installing my coffee cup holder, and placing a sticky rubber mat on the doghouse cover that I can clip my phone onto when I'm using GPS.
