Hi there. I had the 3.5 version of this. Identical engine. Anytime I left her on her side (correct side) or any other way for too long…she ended up with oil getting up into her carb. I’d almost bet that’s your issue. If it’s not…any which way…she will need a good carb clean…then she’ll be just fine. Had mine in bits many many times.
Apparently a common issue with these particular engines. No matter which way you leave them…they can have sump oil get up and into carb. Other than that…great wee engines.