hey guys,

i have an 2003 vstar silverado that i just bought, and im having some trouble with it, its back fireing a whole lot and it had trouble just staying on. i adjusted my idle and i changed the spark pluggs, but its still back fireing especially when i first start the bike and have the choke on. also whenever its all warmed up and im riding and i slow down to a stop the bike will rev really high at first then after like five seconds it will go back to normal, any one have any suggestions?  

yo  

yi  

HI; sounds like you have a vacume leak. This could be a vacume line or around the carb mount. Bad gasket or loose mounting nuts.When the back firing happens is on the intake (air cleaner) or exhaust?
How does the exhaust smell? Have you noticed any smoke out the pipes?
1 Check for vacume leak
2 check the fuel filter Pluged?
3 Check the exhaust pipes at the cyl head.Look for any black soot  leaky exhaust.
4 Intake back fire vacume leak most the time.)
5 exhaust back fire   ( lean condition fresh air getting into the exhaust pipes)
These are the easy things to look for Next would be rebuild the carbs and check the engine timing..
Hope this helps some..scruffy  

This sounds very similar to the problem that I had on my 2001, 1100 VStar.  It was a vacuum leak at the carbs. I took it in to the shop.  They replaced a few gaskets, ran perfect ever since.  

well the it doesnt really smell like anything accept gas, there isnt any smoke comeing out of my pipes and how do i check for a vacume leak, what general area should i look at?  

HI; for vacume leaks you can use WD-40 on and around the carb. Try around the base between the carb and the intake runner. That is where the vacume lines are. If and when the engine idle changes then you have found the area where the leak is. IF a leak is detected you may hae to start taking things apart to fine which vacume hose..Most all that stuff is under the gas tank..scruffy..