Poor running suzuki gsf 650
hi m8,, 1st u need to check the timing with a time light gun,, and trottle the bike to 7000rpm, and see if the timing marks change as u r pointing the gun at it, if they do move ,,adjustment is needed, ,if all is ok u can do a test by taking a plug spanner with u,,and riding the bike up the road, trottle it to 7000rpm,and soon as it stutters hit the kill switch and coast to a stop,, wipp a spark plug and check the colour of the plug, ,u have to look at each plug tho,, if one plug is different colour to the others ,,then the cylinder that plug came from is the problem point,,, another solution is to get your carbs balanced ,,id advise u do this 1st really b4 doin timing check,, cheers