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Discussion Starter #1
I have a 2003 Vstar 650. Recently pulled it out to get ready for riding. Before I put it up last year it was barely running and sounded like it was running way too lean.

Fast forward to this year. I put fresh gas in and crank the bike. It will idle but will pop every 2-3 seconds. Looks like it is only coming from the front cylinder. I can also see a backfire coming from the front carb and have a link posted of the video below.

I have ran seafoam through it. Fuel filter is not clogged. I can't find any vacuum leaks anywhere. The only thing I noticed out of the ordinary was a touch of oil on the tip of the front spark plug. I am thoroughly cleaning the carbs right now. I have v&h exhaust and have the carb jetted. I have 112.5 main jets, 22.5 pilot jets, and adjustable needles with shim on the 4th notch. I'm stumped.

https://youtu.be/oC60jUyUrg8
 

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2008 Vstar1300
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342 Posts
Looks like it could be a sticky valve or maladjusted valve.. Just a suggestion :)
 

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the only way an engine can actually fire backwards thru the carb is if the intake valve is not closing all the way.

when was the last time the valves were adjusted?
 

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Discussion Starter #4
I'm not sure. I havent adjust the valves since I've had it. I've only had the bike a year. But I'll give that a shot.
 
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