1983 vf750s manual, petcock parts and coil connections

Howdy. Trust all is well. Just started to check all of my wiringh to help with weak spark issues (all 4 plugs). The manual download link covers the 1983 vr750F model (interceptor) but there is nothing for the Saber. Does anyone out there have a link I can download? The one I did find last year was scanned from a Clymer manual and is really hard to read (and I don't much like the clymer).


I purchased a rebuild kit for the petcock but notice that the kits fopr 1983 seem to have only one diaphram 9the larger one) and are all missing the smaller one. The kits I have seen online for the 700cc seem to have the smaller one as well but no measurements to verify what will fit what. Does anyone out there know for sure that the 700 and 750 petcock parts are interchangeable?

And last, teh coils do not have markings andi may have crossed the connections. In both cases, is the black/white on the left or right side of the ground/mount bolt? (assuming that the polug leads are on the left side)

Thanks. Hope to get this runing properly and pass on anything I learn that may help others.

Remember. You can ride like the wind without sounding loke a wetfart.

 

The only thing I can help with is the coils, and the answer isn't straightforward...

The easiest way to determine which connection is which on the coil is to check for continuity from each small terminal to the output (spark plug wire connection). The "+" terminal will have continuity to the output, and the "-" terminal will not. The "+" terminal should connect to +12V, and the "-" terminal should connect to the trigger source.

I would guess that there are three wire colors and four wires you are dealing with. Whatever the common color is should go to the "+" side of the coils. The other two will go to the "-" side of their respective coil. If you can't get a schematic, you can swap them back and forth and see what works.

 

Thanks. The coils, if placed side by side and with the wire connectors facing "left", are identical....which is good. I ahev cleaned and reinstalled them but following the wiring loops, I find that one coil has the black/wite wire on the left side of the ground post (and the blue wire on the other side) and the other coil has the black/wjite on the other side (with the blue on the other side of the ground post so I don't know which is reversed. The manual I do have does not really help. I will try to insert an image and that may help.

Ooops, cant insert my stick drawing. looking again at both coils, are the black/white leads on left or right spade post for both?

Thanks

 

Maybe someone else will know... I don't know the coils, so I would have to use an ohmmeter to figure it out.

You could pull a spark plug (or use a spare), connect the spark plug wire and crank the engine over to see if you get a spark (making sure that the threads are grounded to the engine somewhere). If you do, that coil is connected properly. If you don't get a spark, try reversing the coil connections and try again. If you still don't get a spark, there is something amiss.

Whatever connections on one coil that produce a spark should work on the other coil, assuming that they are identical. At that point, the only thing that could be a problem is which coil is firing when (I hope that makes sense). If the wire length limits which coil can be physically connected, that would simplify things.