I put this bike together from ground up, I have 2 f4 motors and wire harnesses and both harnesses get the same results. No spark to the 2 outside cylinders, so imagining that all 4 cylinders are not firing either. That batt is charged full and shows little over 12v, fuses are all good, tried coils from other harness and still no spark. Ive been search to find help for months and found that the pink wire in the ignition is anti theft and can cause this type of problem. The ignition i have, the diode has been replaced with resistor, but the kicker is that it will start my bro's bike all day. Ive tried a couple different ignitions from a few f4is and still get the same problem no spark, but these ignitions the diode has been messed with also so im taking that into consideration. My guess if not the ignition (diode) then maybe rectifier was damaged when changing out different ignitions with different diodes or resistors?

 

oh forgot, tested plugs with my 50 and they spark more than enough

 

check the cam pulse generator, wires to that, theres also a few other sensors in the bike that could cause that. i assume its turning over, make sure that if it had a tip over sensor that its jumped, or still on the bike. most likely its a wiring issue.

 

Thanks for the response, the f4 does not have tip over sensor like the f4i's that i am aware of, the bike is turning over just not firing. when you say cam pulse generator, are you just talking about the pulse generator that comes out from bottom end side case cover? ive unplugged and connected multi meter to prongs and cranked the motor, seems to be getting something from it but dont know what number i should be seeing from it, any help?

 

Hey maybe u could help me with my F4I. Where is the tip over senor located?? I took all the fairings off and now it won't start. Thinkin it must be a senor cuz it was working fine. Help??

 

tip over sensor is behind the headlight last i remember

 

headlight and gauges dont need to be plugged in to complete circuit do they on the f4's? I think ive already tested this but unsure....

 

Yeah thats where it is. I just found it and jumped it out and it started right up. Thanks for the help!

 

wish mine was as easy

 

testing with another ignition and found there is between 8 and 9 volts to the pink wire at the icm, which from what ive read this is correct, but still no fire. Next i think could be bad rectifier or pulse generator. also maybe something bad in switch? switch flips on and off fine and can hear something (sounds like open and close), so that should verify the switch is working? does anyone know how to test rectifier or pulse generator?

 

what about the killswitch? could be damaged and always grounding out, check those connections. i dont know if a bad rectifier would cause it not to fire, on a working bike, if you unplugged the regulator/rectifier, the bike would still run, but the battery just wouldnt charge. have you checked the wires coming from your stator?

 

wires coming from stator? do you mean pulse generator coming from the right side case (if you were sitting on it, right side)?

 

nope, my rectifier went out, and 2 cylinders went out. i replaced the rectifer, and all good.

my advice is get a service manual and a voltage reg. see if its putting out the right amount of juice.

 

i do need the voltage reg to test the rectifier?

 

The ignition resistor is 2.2k ohm 1/2 watt 5% tolerance in case you ever have to replace it. But thats not the problem if you took the ignition off and tested it on another bike.

 

thanks man this will help repair at least 1 ignition i have, still havent figured the no spark issue out with good ignition, may take it in if moneys right, tired of fuggin with it

 

Yep, yep. The part number at Radioshack is 271-1121 for a 5 pack of resistors. They are like a dollar but the resistor is quite a bit bigger than a factory one. PROTECT THE RESISTOR so it don't break!!! I usually slide a piece of rubber tube over the resistor and soldered wire then tape a cotter pin to the hose so it wont flex.

 

if the coil wires are swapped it will fire 180 degrees off.... try swapping them

 

?

 

So did you ever fix it? I have the same problem.