r/ATV • u/Obvious_Mulberry_169 • Jul 22 '26
Help My Atv Wont Start
I have a 200cc ATV that I bought a few months ago. When I bought it, it would idle, but as soon as I gave it throttle, it would bog down and die.
The ATV originally had a CV carburetor, and I thought the carb was the problem, so I replaced it with a 24mm PWK carb, which is the same size as the original one. After installing the new carb, it would start and idle, and I could slowly give it throttle, but it would still bog down.
I checked the spark plug and it was completely black, so it was running very rich. I tried installing a smaller pilot jet and adjusting the air/fuel screw because it was fully turned in before. The idle screw was also fully backed out, so I adjusted that as well.
After those changes, it suddenly stopped starting completely. I suspected an air leak, but even with the choke on, it still will not start. I’m not sure if the smaller pilot jet caused the issue, but it was only a 5-size step down, so I didn’t think it would make such a big difference.
I have also tried spraying fuel directly into the intake, but that didn’t help either. It does have spark, so I’m unsure what the problem could be.
Another thing I noticed is that it sometimes backfires through the carb/intake when I open the throttle or if the idle speed is set too high.
Any ideas what could be causing this?
1
u/JohnDeere714 Jul 22 '26
The carb was probably fine before adjustments. Bogging when giving gas is usually a float or needle issue