I have a few Quantums with the snorkel ,they are a lot better at keeping dirt etc out of the engine.

If it's not making a popping noise out the muffler or backfiring it sounds like a carby problem ,I've
had a few that the fuel hose was so old it would slowly disintegrate and block the main jet ,I would
remove the fuel bowl and it was spotless but then when you put fuse wire up the main jet it would
dislodged the small rubber fuel line debris ,then the motor would run without a problem.

Here is a carby guide https://www.outdoorking-forum.com.au/forum/u...r-problems-and-solutions.html#Post104746

Cheers
Max