TOPIC:

Just make sure the spark can go from one spark plug wire to the other spark plug wire (on the same coil). The gap between the two should be no more than 3/8 inch (1cm).

Hopefully will I be able to install the new coils next week and test them, if I not come any further with new coils and plug cabals,
will I try to test the IC ignitor. Must I use some special cables for test bench ? Just some ordinary electro cables for car and mc? and make correct air gap?

Ordinary 16ga wire is fine for bench testing. Even 18 gauge might work for testing.

I have now recived part parts, but I`m going on vacation today, so I need to test the coils and new cabels when I come home.
So be prepare for a update in 2-3 weeks

Sorry for the delay!
I'm really appreciate all the help from everybody.

Today have I installed the new coils and the spark plug cables. These upgrade was not solving my problem, engine will not start...
I can hear sometimes it try to start at least one cylinder starting?.. but never start up and going... And it comes smells from the exhaust (loud) and sometimes from the pod filter on the carbs... when I ty to start and the start engine has runned for 5-6 seconds, giving some information what happens?

VIdeo:
temp.dynamitt.net/div/MC/IMG_4265.MOV

The "funny" thing is that when I bought the bike I never had problem to start the engine, the problem was it was not going okay on higher RPM I was missing torque... and I rebuild the carbs and rejettet, adjusted the valve without any success, and then suddenly on one test drive it was working perfect... and then next day back to "standard" problem missing torque... I think I was only going on 2 or 3 cylinders, when these problem arise? I have maybe has 5-6 test drive and it`s only one time the bike has runned fine.

But when I tried to find a problem with the bad electrical connection I was disconnecting one coil and tried to start etc to see if I had same symptom etc.. I have now learn I can use water on the cylinder to see what is running, but diffident know it then... and after these I have problem to start the engine atall, before these electrical troubleshooting it was almost stating easy and running fine on idle.

I`m afraid I have damage something ?

Can it be I have damage the IC ignitor? or maybe I have a broken wirer now and before it was only bad... ?

Plan further:
1. By 4 new spark plugs, they are cheap so I will be good just to make sure the spark plug is not the issue?
2. Test the IC iginitor the way explained earlier in these post? How do you connect the cable to the coil? can I just remove alot of isolation on the cable and push a lot of un isolated cable in the whole in the coil ?

Thank you for help in these matter, I have now used long time to get the engine running properly, hopefully will I be there

The spark plug wires are not correct.
One coil should be hooked up to cylinders 1 and 4. The other one should be hooked up to cylinders 2 and 3.
In the pictures, I see the left coil (picture 1) is connected to 1 and 3. The right coil (picture 2) is connected to 2 and 4.

Two questions. Is it possible you have the leads reversed. Will 3 OHM coils burn out the igniter?
Steve

TexasKZ wrote: The spark plug wires are not correct.
One coil should be hooked up to cylinders 1 and 4. The other one should be hooked up to cylinders 2 and 3.
In the pictures, I see the left coil (picture 1) is connected to 1 and 3. The right coil (picture 2) is connected to 2 and 4.

Good eye. You may be right. Beggs the second question, will the 3 OHM coils work with the igniter?
Steve

SWest wrote:

TexasKZ wrote: The spark plug wires are not correct.
One coil should be hooked up to cylinders 1 and 4. The other one should be hooked up to cylinders 2 and 3.
In the pictures, I see the left coil (picture 1) is connected to 1 and 3. The right coil (picture 2) is connected to 2 and 4.

Good eye. You may be right. Beggs the second question, will the 3 OHM coils work with the igniter?
Steve

I am certainly no electrical expert, though I do know that before you try to stradle an electric fence, you should be dang sure your legs are long enough
As I recall, the factory coil specs were 2.3 to 2.8. If that is correct, then a 3.0 should not be too much of a stretch.
I also wonder about the primary wiring to the coils. It is fairly easy to get it backwards.

As TexasKZ pointed out, you have the coils wired wrong.

On the smaller engines, including the 750:
The right hand coil, as you sit on the bike, should get the small black wire and that coil fires cylinders 1 and 4.
The left hand coil, as you sit on the bike, should get the small green wire and that coil fires cylinders 2 and 3.

As you sit on the bike the cylinders 1,2,3,4 from left to right.

The ignition rotor can also be backward, so you should check that as well (otherwise proper wiring won't work).

Here is how the rotor should be:
When cylinders 1 and 4 are at top-dead-center, the pointer of the ignition rotor should point backward toward the pickup with the black and blue wires.
When cylinders 2 and 3 are at top-dead-center, the pointer of the ignition rotor should point forward toward the pickup with the red and yellow wires.
(The pointer won't be at the center of the pickups, but just in the general direction. The pointer will be closer to the center of the pickups when the F mark lines up, but that is not TDC.)

The 3 ohm coils should work fine with the stock ignition as long as the motor internals are stock and in good condition, and the spark plug gaps are normal.

Thank you all,

I will take a look at these after work today, I don`t think the wiring is original, see attached photos.

To be 100% sure wiring to the coils is correct, can I use the IC ignintor test, to see what coil firing when I active the sensor rotor sensor for 1-4 and 2-3 ?

The problem now will be that the cables are to short, so hopefully will I be able to use them for test by having the coils loose.

Can I use something like these for testing (then I will be able to get one local in my town): ???
www.mekonomen.no/bil/reservedeler/tennpl...-syl-1-ps24a19-R01no

For bench testing, you don't need special wire. Any copper wire will work. Just make sure there is a complete path, as shown in the drawing I posted.

If you're lucky, there might be enough wire to still reach. Is it possible to mount the coils with wires pointing down? Maybe not.