You probably do have a case, but honestly the strength depends a lot on how specific that "10-year lifespan" claim was. If they said something like "engineered to last 10 years under normal use" that's pretty clear cut. If it was more vague marketing language like "durable" or "built to last," that's murkier legally - courts have been all over the place on what counts as a concrete warranty versus puffery. The 14 months versus 10 years is a massive gap though, so you're not dealing with a minor wear issue here.
Before you even think about a lawsuit, try this angle that doesn't get mentioned much: contact the credit card company or payment service you used. If you paid with a credit card, most of them have purchase protection and false advertising claims built into their chargeback process. It's basically free, takes maybe 20 minutes to file, and the payment processor does a lot of the heavy lifting. You might get your money back way faster than dealing with small claims court or complaints to the attorney general.
If the chargeback doesn't work, then yeah, small claims court in your state is the move before anything fancier. Keep everything - the packaging, screenshots of the website, photos of the dead motor, your receipt, any emails with the company. Document exactly when it failed and how you were using it. Small claims has a much lower bar for evidence than regular court, and you won't need a lawyer.