Why is My Honda ATV Carb Backfiring?
If you have a Honda ATV that keeps backfiring from the carburetor even after you rebuilt the carb, you may have to go back in, remove it and do a deeper cleaning.
Partzilla’s Honda ATV expert John Talley hosts live Q&A sessions on our YouTube channel every Friday at 3pm Eastern. In this session, John was asked why a 2002 Honda TRX400EX could be backfiring even after a carburetor rebuild.
Honda TRX 400 Carb Backfiring Q&A
I have a 2002 Honda 400EX that backfires through the carb. It won’t idle and stalls out, but it runs fine on top, pretty strong. However, it sat for a while, says the person I bought it from. I did a carb rebuild and still the same issue. What could be wrong?
John Talley: Alright, it sat for a while and you used a rebuild kit, and may have had new jets put in there. But those jet orifices are not much smaller than orifices inside of the carburetor. If it sat up for that long, more than likely the carburetor passageways are now stopped up as well. And most times just trying to spray a carb cleaner through it probably won’t do the trick. It’ll probably need to go in a carburetor dip. Some of the best dip that I’ve used is made by Yamalube. They make one that you can run just about full strength, where you leave it submerged for 4-6 hours, somewhere in that range. Just don’t leave it in there overnight. It usually has a better chance of cleaning out those inner passageways. Then use high pressure air to blow through it. But it sounds like the smaller passageways, which are always associated with the idle and intermediate fuel circuit, if you will, they always seem to get stopped up first because they’re smaller. So it looks like you need to go back into the carb and do a little bit more thorough cleaning.
Watch the video below to see how to clean and rebuild a Honda TRX400 carburetor.
Watch the video below to learn about whether you should clean, rebuild or replace a carburetor.
Watch the video below to learn how to troubleshoot Honda TRX 400EX ATV starting problems.
Want to see more live repair questions answered? See more motorcycle and ATV repair questions answered here.
