I am a new rider this year and just purchased a VStar 650 classic. It runs great but when I down shif every so often it back fires. The dealer said this is normal. Any thoughts???

I am a new rider this year and just purchased a VStar 650 classic. It runs great but when I down shif every so often it back fires. The dealer said this is normal. Any thoughts???

Hello and Welcome,

I had a similar problem which although on a 1997 Dragstar 650 sounds very familiar. In the end it was caused by a air leak through the rubber inlet manifolds which had cuts/splits in them causing air to get in making it backfire on deacceleration. Have a very close look at your manifolds looking for hairline cracks (although mine were more like string size !) Found out new ones are expensive so covered them with high temp. clear manifold gasket in a tube which has done the job.

Have a hypercharger fitted too and the air pipes going to that were split so was even worse than yours ! lots of pop,pop,poping.

Have not been a member here long but a great place for infomation and answers.

Hope this helps.

Graham.

My 650 only did that when a hole developed in the exhaust pipe.

It would fire whenever I rolled off the throttle.

Check also your fuel/air mixture as that could be too lean, causing unburnt air to burn when it hits the exhaust system - Hence the pop... or BANG if it's a large hole.