White soot on exhaust

I fly a 172 with an 0300D
Last summer I purchased an EI Engine monitor.
It monitors EGT and CHT on all 6, plus several other functions.
After purchasing it, it led me to a problem valve, and it taught me how
to lean my particular engine in every phase of flight.
It has given me a confidence in my engine that I never had before.
I strongly suggest that you invesigate one as the next purchase for your
aeroplane

--

Tony Roberts
PP-ASEL
VFR OTT
Night
Almost Instrument
Cessna 172H C-GICE