Husqvarna 372 xt. Started really well cold today & seemed to run good in the cuts. But after the first cuts and for the rest of the day it would speed up and then back down at idle and continue to hunt back and forth. It’s Never done this before. I was running different fuel mix today, had been running 100 octane av gas. Today was 91 e-free. Same oil @ 40:1. Air leak maybe? Or could the difference in fuel cause it
Difference in fuel. The 372 xtorq coil retards the timing below about 3200 rpm for easier starting. Your new mix was causing the idle to be a tad high. Might need to be tuned or just back the idle down a tad
They do make it considerably easier to tune this type of carburetor. Fortunately they are really inexpensive on eBay for a whole set
