I have a lawnmower and a snowblower, both from Honda, and both are hard to start at the beginning of their season. The lawnmower is the worst offender, by far, so I'll focus on it.
I would always get the mower going, but it could take all day the first time. After that initial difficult start, starting was reasonably easy for the rest of the season.
I have heard various theories on why this is so:
- Gas varnished up over the winter. I took the carb apart - clean as a whistle. Nor did gas stabilizer make any difference.
- Water (from condensation) in the gas. Hmm, hard to do with the 10% alcohol in all gas available these days.
- Volatiles evaporating from the gas in the tank over the winter. Also, various stories saying that winter gas and summer gas are different, the difference being how volatile the gas is, with winter needing more volatile gas than summer. Hmm, this could be at least part of an answer.
So, this year, when I first tried to start the lawnmower for the summer, had the usual problems. Tried the usual dodges, like leaving the mower out in the sun to warm up, and putting fresh gas in the tank, but no go.
Volatiles? Ether! So, I gave it a squirt of starting fluid.
Started right up on the first try, and subsequent starts were of normal difficulty, probably because all the old gas was by then flushed out of the carb.
So, theory 3 seems to be correct.
And a dash of Naptha in the gas may do the same.
Joe Gwinn