backfire at high rpm

[87banshee350]

hi, i did a search and couldnt find anything so ill ask, its an 87 banshee with stock carbs, 280/25 jets needles are on the 3rd line the middle line, dg pipes, and im running mc-1 oil at 40:1, it runs great it just has a backfire when tacked out and the right side blows a little more smoke then the left thanks in advance for the help

[ellison445]

Check your plugs, sounds like your lean

 

hi, i did a search and couldnt find anything so ill ask, its an 87 banshee with stock carbs, 280/25 jets needles are on the 3rd line the middle line, dg pipes, and im running mc-1 oil at 40:1, it runs great it just has a backfire when tacked out and the right side blows a little more smoke then the left thanks in advance for the help

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[Banshee_Guy]

It could be timing, but most likely too rich. Do a WOT test and check your plug color and go from there!!

[ellison445]

Backfire is not a sign of the bike being rich

 

It could be timing, but most likely too rich. Do a WOT test and check your plug color and go from there!!

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[87banshee350]

well now its only backfiring out of the right side its shooting a 4 inch flame out the silencer and doing it when reving it up, and it dont have as much smoke as the other side, the plugs are a light black

[H300F]

Check for leaks at the carb boots, check the spark plug wire, and coil, clean the carbs jets.

[banshee350twin]

do what they said and how the dg pipes sound ?

[Capone]

Its too lean, and if its backfiring I'd pull the head off and check the pistons, if they look pitted, then pull off your jugs and check around. How long has it been running like this? Search the forums for a "Air Leak Test".

[87banshee350]

i just did a top end rebuild and swapped the carbs with better stock carbs and thats when it started, it runs better and gots more power but has the backfire.

 

and the dg's sound good but would like to get the T5's