Topic: cb750 no spark at plugs

[jamesb]

let me start off by this is a chopper the wiring is the same exact one as the simple wiring diagram i took my points cover off i'm getting spark there took out one of the plugs #4 cranked it over no spark put it back in took out #2 same thing. could the coils have gone bad just like that.

[Trav-i]

IF the orginal coils were used, check for power at the black and white wires.  There should be 12 volts there, if not you'll need to track down why you lost voltage.  It's rare for coils to just up and die, it's usually a long slow death for coils.

Travis

[jamesb]

they are not original coils they are off a harley there is no power to the wire that goes to ignition on the wiring diagram. i'm thinking it's because the harley coils is why it wont start.i've used a part from a harley on my 550 now it leaks oil.

[Xnavylfr]

Run you a HOT wire from the + post of the battery directly to the power of the coils. By doing this you remove all the other connections that may be bad, you can even put a 30 amp fuse in-line to be safe.
Some of the guys that have that wiring diagram ,have had trouble with the IGN switch when you turn to start..
send me an e-mail @ chuckschoppers@yahoo then I'll give you my phone #, be sure to mention CB750 wiring in title..

You can use ANY on-off switch in that wiring and make it work!!


Xnavylfr(CHUCK)

[jamesb]

hey thanks for the info tomorrow i'll do that and i'll email you thanks again

[Spanner 1]

Must have 5 ohm coils for operation on your bike.......... what are those H.D. coils ??... not all coils are the same, ya know