Junker wrote on 10/10/19 at 16:10:12:2. I'm stuck with a severe bogging and carb backfiring issue at any acceleration, or holding speed over 40 mph. I have cleaned the carb, tried almost every poss combination of jet changes, including setting to stock. Have run the bike with and without the air box cover, and have placed in a clean filter. Nothing has helped. The tank is clean and fuel is flowing strongly out of the gravity feed petcock.
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The way our carbs work is that when you turn the throttle, it opens a butterfly valve which allows more air to pass through the carb. That moving air creates a vacuum that pulls the slide up to allows more fuel/air a mixture (this mixture is controlled by your jetting). If that slide sticks at any point, the system will go lean because the butterfly is taking more air, but the slide isn't giving more fuel. So, you can throw whatever jets you want in there and you will end up lean anyway.
Mine would stick momentarily during acceleration creating a lean condition in the midrange. I attempted to jet around the issue because I just assumed that it was simply lean in the midrange. Then it got worse. Once it wouldn't go over 20 mph. Another time it got stuck while going 45.
I cleaned mine a few times but it would still stick. I replaced it with a new slide and when I rejeted, I actually ended up leaner than I was before. My bike ran much stronger, it stopped backfiring (even on deceleration) and my fuel economy went up. It was the best $120 I spent on the bike.
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