no spark at 2 and 3 cyls....not coil

1981 750 swaped coil leads from 1 and 4 and it fires then,any one have a direction to look??

Thanks

Have you checked to see if you have voltage going into both coils?

not yet,broken lead on my meter, I will have to stick a wire in it for now.

Do you have a test light?

I can spin one up or just make a lead for my meter,dont want to throw parts off my 550 at it (if they interchange that is)if I can track it or get help here first.

Thanks

Pick up a cheap little meter under $20 is good enough...
Problem with light meters, is they will turn on under +12Vdc so ok for somethings but not actual voltage, resistance or current measurements...

If you have a Harbor Freight in your area... Pick one of these ups for it also does tach and dwell.... Nice little unit for the price....

OK, so if you switched the coils and it fired on 2&3 then only a couple of places is the problem...

1) As mentioned, no +12Vdc to the 2/3 coil.
2) Faulty 2/3 coil
3) 2&3 Spark plug conductor/cap faulty. Doubt this one but possible....
4) 2&3 Ignition components faulty... either points/condenser or electronic pickup as well....
5) Open continuity in conductor (break in conductor) feed from power or ignition plate itself to the coil.

As mentioned and truly wise advise, a DVM (Digital Volt Meter) is a required tool you need in your possession especially on a 30 year old wiring harness and electrical system...

Let's see, did I forget something.... Others feel free to chime in...

OMR

I do have a good meter just the lead is broken off in the hole,I will have to dig it out and fab something up,thanks for the help,really dig your bike by the way, I followed quite a bit of the build seems a couple years back,have not been around much.....I took a good fall and have been out of things for the last couple years,I just picked this clean 750 and it got me motivated to head out to the garage and get going on it.

Thanks again.

Plug cap might have faulty connection to wire.

Sometimes helps to remove cap and trim back the wire (snip off a short piece) whereby the cap may be reattached with a better connection.

Do this on both wires to assure good connections with both caps.

Good Fortune!

got voltage to the coil,swapped it with known good one and it fires on all four????kinda weird when it fired swapping the leads:unsure: , but now it backfires ,lean condition?unburned fuel in the pipes?....I figure I have to clean the carbs again,I cleaned the carbs,muratic acided the tank,put on a russel bronze fuel filter, I thought I got them clean but must have missed something.

the bike sat for a few years,someone laid it down with 12000 miles on it and busted the fairing.nice clean $50.00 score though.

damn rookie.


thanks guys,your the best.