Topic: '77 750 no spark on 2&3

[Kellielagl]

I have a spark tester that plugs into the wires and I can see if I get spark to the plugs. I had great spark to 1 and 4 but not to 2 and 3. I ordered  a new coil and installed it but still no spark to 2 and 3. I have checked the wires by the brake to see if they are attached and they are. What should I be checking next?

[Airborne 82nd]

First off the kill sw must be working because you have power to one coil but check to see if that short little jumper is on going from one coil to the other. If that is ok now it is time to take the points cover off you will see a yellow and blue wire yellow is 1-4 that you say is good so look at the points with the blue wire and see if they are opening and closeing  compare it to the other set.

[Airborne 82nd]

I don't know what you are looking at around the brake? Check what I said if it looks good and you don't find anything repost for some voltage checks

[Kellielagl]

I don't see any cable going from one coil to another. Where is it supposed to be? Do you have a picture of it?

[Airborne 82nd]

There is a black or black/white wire that goes to one coil it comes from the kill sw. with the key on and the kill sw. in the run position you should have 12vdc on that small black wire that is why one coil is working on that same wire there should be a short little wire going over to the other coil at the same spot. That is how the second coil gets its power. So both coils should have a black /white wire and one will have a blue wire the other a yellow wire.

[Stev-o]

How old are your points?  Properly gapped??

[Kellielagl]

Ok, found the black/white wire and both coils are connected to it.

Not sure on the points as I just bought the bike. I have gone through the regular maintenance checks (valves adjusted, air, oil, carbs) except the points and condenser.

[Airborne 82nd]

Ok, found the black/white wire and both coils are connected to it.

Not sure on the points as I just bought the bike. I have gone through the regular maintenance checks (valves adjusted, air, oil, carbs) except the points and condenser.

You left out the most important part ( the part that is not working). Do you see where the points are? What made you change the coil and just what coil did you buy?

[Kellielagl]

Hahaha! My cousin told me to change the coil, probably shouldn't have listened to him. When checking the points am I just looking to see if they both open and adjust the gapping? Bought the coil from z1parts

[Airborne 82nd]

Hahaha! My cousin told me to change the coil, probably shouldn't have listened to him. When checking the points am I just looking to see if they both open and adjust the gapping? Bought the coil from z1parts

Yes to start with see if the set that is not firing looks like the set that is The gap should be .012-.016. The coil should be a 5ohm primary and the caps should be 5K ohms.

[MoMo]

You verified 12v at each coil.  Since you have spark on 1 and 4 I'll address 2and3.  Make sure the yellow wire connected to the points is not touching ground, with the indicator behind the point plate a few degrees past the T mark for 2/3 set point gap as mentioned above,  use either a point file or emery board along with some contact cleaner to remove any dirt or carbon deposit from that set of points, follow the yellow lead and make sure it is not grounded and the connection by the rear brake light switch is tight, then follow that up to the coil and make sure that connection is secure...Larry  my guess is your points are dirty

[Airborne 82nd]

I have a spark tester that plugs into the wires and I can see if I get spark to the plugs. I had great spark to 1 and 4 but not to 2 and 3. I ordered  a new coil and installed it but still no spark to 2 and 3. I have checked the wires by the brake to see if they are attached and they are. What should I be checking next?

The points for 2-3 have the yellow wire and are on the left side  I would not mess with the other side yet get 2-3 working first. Then you need to start the tuneup over it has to be done in the correct order or it will not work right. When you change points you change timing.
1 new plugs adj. gap
2 adj. cam chain always before valves.
3 adj valves
4 adj.points and I check dwell always before timing.
5 adj timing
6 carbs allways last

[Spanner 1]

What should you be checking next ?... what you should have checked first was 'how to set your ignition points'... 'prolly 100 posts on here explaining in very easy steps how to do it..... sorry you wasted money on a new coil ( they almost never go bad )...

[Kellielagl]

Got ya! I have been going through the maintenance as listed in the manual. Haven't gotten to the points yet and didn't know that would make a difference with my situation but thanks for clearing  that all up for me 

[Airborne 82nd]

Got ya! I have been going through the maintenance as listed in the manual. Haven't gotten to the points yet and didn't know that would make a difference with my situation but thanks for clearing  that all up for me 

Well luck and good night. Please let every one know what you find it really helps others that may have the same issue later on. That is why this place so good. Lots of good people trying to help other.

[Vinhead1957]

Focus on the set of points that have the yellow wire.   Make sure the connection on the points is insulated from the base. This is a common problem. The condenser and yellow wire have an insulator on the mount

[Kellielagl]

What did u mean by adjust cam chain "all ways"? I only read about the tdc plus 15 degrees the loosen and retighten. Is there another way?

[mrbreeze]

You said the wire going to the other coil is there but you didn't say if you had power to it. I had a bad connection last summer at that very spot. From the kill switch the wire comes to a double female bullet plug with the clear plastic over it. Each coil plugs into it with a male bullet. Mine were present and plugged in but no pow pow to 2&3. It was a bad connection that was buggging me intermittently for months. It can't be said enough here........clean tight connections!!!! Hey it cost you a coil didn't it? I had a couple of other questions also. Do you have a manual for your bike? Are you using a test light,DVM,dwellmeter,or timing light? One good thing for sure is you found your way to this site. This place will get you an answer to just about anything you can think of related to these machines.

[Kellielagl]

1- my cousin checked but to be on the safe side of things I will check myself. (He has need known to be wrong haha)

2- I have downloaded the manual on this site and am using the CRAP out of it.

3- timing light

This forum is freaking awesome with lots of knowledgable people!

[Kellielagl]

I installed carbs last night on bike and have a few questions.
   1- the old owner had a hanger holding the crabs up to the frame. Weird, but why?
   2- I was checking the float bowls to make sure the gas was getting in there after I messed with the floats and when I was draining the gas from each one I noticed that the gas was pinkish/red. Opened the gas cap and the owner said he had sealed the tank. It is sealed with some red stuff. I have not seen sealer that is red before? Draining tank now and drying it. The gas doesn't even smell like regular gas (if that makes sense) Do you think this is a problem?
   3- the petcock only works when turned to "reserve" and only comes out 1 nipple not both. I get no gas when turned to on. No gas when turned to stop.

[Airborne 82nd]

What did u mean by adjust cam chain "all ways"? I only read about the tdc plus 15 degrees the loosen and retighten. Is there another way?

This is why it is important to do every thing in the proper order.
I meant always adjust the chain before you adj. the valves. the cam chain effects the valve adjustment. Same thing with setting your timing your points adjustment effects your timing so adj. point first then timing.
About the tdc it has to be 15 degrees after TDCC on the compression stroke.

[Stev-o]

1. The PO is a dumbass

2. Redkote? Big problem, you need to strip it out. The PO is a dumbass.

3. Obvious problem, need to service it or get a replacement. Could be the tank sealer has clogged it.

Progress...

[Airborne 82nd]

I installed carbs last night on bike and have a few questions.
   1- the old owner had a hanger holding the crabs up to the frame. Weird, but why?
   2- I was checking the float bowls to make sure the gas was getting in there after I messed with the floats and when I was draining the gas from each one I noticed that the gas was pinkish/red. Opened the gas cap and the owner said he had sealed the tank. It is sealed with some red stuff. I have not seen sealer that is red before? Draining tank now and drying it. The gas doesn't even smell like regular gas (if that makes sense) Do you think this is a problem?
   3- the petcock only works when turned to "reserve" and only comes out 1 nipple not both. I get no gas when turned to on. No gas when turned to stop.

I would not jump around to fast. Have you solved the firing issue yet?
" holding the crabs up " Not sure what you are talking about. Does your bike have VD?

[Kellielagl]

Airborne, thanks! Doing cam adjustment today and will recheck the valves.

What's the best way of getting that redkote out of the tank?

Gotta get a multimeter today and check the wires myself. Cousin must have taken mine thinking it was his haha.

 It was supposed to say carbs, oops 

[Stev-o]

What's the best way of getting that redkote out of the tank?

Methylene Chloride