Post
by johnr » Mon Jan 31, 2011 8:38 pm
chances are that you have a bad connection within the handlebar button. simple test is, if you press the button and theres a click from below the seat, then your switching side is ok, and the problem is downstream of the starter relay. if you press the button and dont get a click, then take the starter button apart and give it a good clean out inside to make sure it connects ok. its a common thing on bikes not used much!
bad earths can make the starter not spin fast enough, as the current struggles to overcome the resistance of the poor earth. remember that when the solenoid clicks, the power goes from the battery plates(lead) via the bolt and mounting for the power lead(brass) into the lead(copper) down to the starter relay(copper and steel, via 2 brass connections onto copper cables) down to the starter motor(steel, carbon brushes, copper armature steel shaft ) down to earth in the engine(ally) then the current has to go back through the casings to the frame(steel and rust!) to the earth post(steel rust copper brass, other wires, insulation tape, paint powdercoat etc) down the lead(copper) into the battery terminal(lead) etc etc, now every change of material creates resistance, every change in cable size adds resistance, every connector and bit of crap in the way adds resistance and thats why your starter motor lurches, but your wiring is almost glowing red with the heat. so, as the starter motor is by far the heaviest user of power on the bike, i like to make it easy by making the route back to the battery as easy and short as possible.
a seperate earth to the casings clost to, or better still straight onto one of the mounting bolts of the starter motor will give the starter battery and wiring system an easier time all round.
