Topic: '77 750 no spark on 2&3

[Airborne 82nd]

Stev-o is right on that for sure. You can make a temp. gas tank just for tuning the bike. You need the bikes tank out of the way any how. You can make one cheap out of a old lawn mower gas tank plus they have a shut off valve on them. But your tank will need a complete cleaning or that stuff will keep on screwing you up.
I bought this one.
 http://www.motorcycle-superstore.com/10118/i/motion-pro-auxiliary-fuel-tank?SiteID=SMPR_BG_07_31_TTTMPAuxFlTnk&WT.mc_ID=14026

[Airborne 82nd]

" 1- the old owner had a hanger holding the crabs up to the frame. Weird, but why?"
Good question and the first thing it brings to mind is the stock air filter system on this bike? That is what would normally hold the carb rack up.

[Kellielagl]

Steve-o why is this Redkote stuff bad? I have never personally used it but it says it seals gas tanks...
Obviously it's not gas resistant hahaha

[Stev-o]

Steve-o why is this Redkote stuff bad?

It's not a bad product but something went wrong. Most likely, the tank was not prepped properly.

I've used the Caswell epoxy coating on two of my tanks, great product, highly recommended.

http://www.caswellplating.com/restoration-aids/epoxy-gas-tank-sealer.html?gclid=CjkKEQjwk9CcBRDEopHmnZa5td8BEiQAr2BckB4NdV9DMFCs-3DH92wkFUDGWoO73mYfUGgN8CHieEHw_wcB

[Kellielagl]

Ok, I have power at the connector, where bot coils hook to, but it's only reading 6.32volts. Is that low?

[Kellielagl]

Trickle charged the battery for a bit and now have better voltage on everything.

I have good voltage at the black/white connectors. Blue connector for the coil that's working has power but the  yellow does not. I only have .22 voltage on the yellow wire anywhere I check. Confused on where/what to check  next. The wiring diagram shows the yellow going to points and condenser. Nothing there either.

[Airborne 82nd]

Ok, I have power at the connector, where bot coils hook to, but it's only reading 6.32volts. Is that low?

Yes that is way to low you should have battery voltage at both coils. Where did you have the meter leads connected? Maybe the black meter lead was not grounded good. Try red lead on the black/white wire at the coil and black meter lead on the green ground where the coils mount to the frame. One of the first thing I do to a new to me bike of this age is disconnect EVERY wire from the headlight to the tail light. It is the only way I can have peace of mind going down the road 20 miles from home at 2am. It may seem over whelming at first when you pop that headlight out of the bucket but you can do it. I have never seen 6.32vdc except on a 51 chevy Just to get it going you need to clean all the fuse holders. Wires at the key switch kill sw. coil wires and all grounds

[Kellielagl]

After a little charge I am getting 10 volts going into each coil. I get voltage on the blue wire ( one that is working) but very little on the yellow wire.

[Airborne 82nd]

After a little charge I am getting 10 volts going into each coil. I get voltage on the blue wire ( one that is working) but very little on the yellow wire.

No reason to take any more readings until you get the battery up to 12.6 minimum 12.8 to 13 better.

[Airborne 82nd]

Forgot you should still have the same reading as the battery if not you are losing it through bad connections but get the battery up to 12.6-12.8 first.
EDIT check the battery after charging and let it rest not hook up to the bike for two hours before taking the reading.

[Kellielagl]

Ok I will charge it up tonight.

1- the PO installed this toggle switch instead of having the key switch. They tapped into the wire harness (see pic). upon checking wires my hand touched where he connected the toggle to the red and it is way HOT. The other end is connected to the red as well but is not hot

2- opened headlight and saw that a brown wire is twisted with a brown/white and a red twisted with a black wire

Holy crap! hahaha, what a mess. Not sure if any of this would cause my problem

[MoMo]

Not the spark issue


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[Airborne 82nd]

The person that did the wiring should not be allowed to EVER work on electrical parts until he learns how to do it right. You really need to go through the complete harness and clean things up no wire nuts or tape.
Here is good how to with great parts to do it right.
http://www.oregonmotorcycleparts.com/ConnectionRepair.html

[Airborne 82nd]

The brown & brown/white does indeed connect together in the bucket that is correct ( with bullet connectors). Brown is your tail light so with key on tail light comes on. The brown/white goes to the little lights in your speedometer and tachometer so now they come on when ever tail light is on. The red wire comes from the start sol. goes to main fuse comes out of fuse then goes to ignition sw. The black wire is switched power that means whith the key sw. on the black gets hot and feeds several things throughout the bike that need it. Don't know why anyone would tie it to the red?? Take it apart and see what happens. Get rid of those red crimp on connectors.
EDIT the red to black is where the key sw. would have connected if stock.

[Airborne 82nd]

 Heat on a connector could be loose or dirty contacts. I don't see that toggle sw. but maybe that explains why the red & black are tied to each other.

[flybox1]

The pinkish color to your gas could be Marvel Mystery Oil.
I coated my tank for winter with MMO, and when I flushed it before its first start, it had that blush wine color 
If your tank is showing bare metal inside...I would assume its just MMO.  Rinse it out with a pint of gas, and then use that gas in your mower, or just fill your tank and run it.  It wont hurt.

[Airborne 82nd]

Not the spark issue


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True

[Kellielagl]

thanks for the info guys. I will work on the wiring while the tank is getting cleaned out.

flybox the gas was a dark red when i emptied tank

air box the toggle is attached to the 2 news wires that were spiced in