So I got this 90cc Panterra atv. When I first got it, I manage to get it to start for like 1-2 mins. Died on throttle. So I took the carb apart cleaned it completely, I know. It's sounds ignorant' kinda is, but. I forgot to take this bolt out that held a integrated filter. And it still had a small, amount of water in it. When I reinstalled it. I reinstalled it. It wouldn't start. I emptied the oil and filled with new oil. And took spark plug out and used qtips and a hair dryer to get the water droplets out. After all this. I went ahead and just bought a new carburetor and I can't get it to start. It has spark. Fuel. Compression I believe. I'm stuck on doing the valve clearances. The best I can get it to do. Is backfire from the carb. Any suggestions? Thanks.

 

I am sure it is not true in every case, but backfiring through the carb usually means lean mixture, or you have a timing/valve seating issue.

You could try starting it on starting fluid. See what happens. Might help point us in the right direction.

Otherwise, if it was mine and it had never run, I would start with a compression check. That will give you a rough idea if the valves are seating, timing is close and piston rings are good.

Do you have a harbor freight close by? great place to get tools good enough to do this work for cheap.

They have these spark testers, they are great. Plug them in, leave them on. So you always have a visual reference while getting something going.
https://www.harborfreight.com/in-lin...ker-63590.html

If you have spark and decent compression then you know for sure you are not getting enough fuel in there. Which also might be what using starting fluid will tell you.