Topic: No spark suddenly. I'm lost.

[mrbreeze]

I'm still not sold on Dave's bike being fixed. I would be going over the whole circuit with a fine tooth comb. Maybe do a really thorough wiggle test on the wiring. The problem I had 2 years ago keeps going through my mind and it involved what you guys are hitting on......upstream of the coils. My problem was only taking out 2-3 which could be related to Dave's problem. He said everything was fine until he hooked up the yellow wire. My problem turned out to be the connector where the wire from the kill switch branches to 2 wires to feed each coil. It is a power wire so the connection point is shielded. It is 2 females.....each coil has a male that plug in there. I found the problem by wiggling the wires while it was running. 2-3 kept dropping off. The male plugged wire wasn't making a tight connection although it still appeared to be connected. Over time the arcing that was occurring there was corroding the metal. I clipped that connector out and installed new bullet connectors. I have had no problems since.

[Davez134]

I'm still not sold on Dave's bike being fixed. I would be going over the whole circuit with a fine tooth comb. Maybe do a really thorough wiggle test on the wiring.

I'm not sold on it being fixed either. So I'm going through it all!




When you say go through it, do you mean checking resistance? Continuity? I'm still learning this wiring stuff.

While checking 2-3 coil for peace of mind, I found resistance on secondary side was intermittent, based on position of wires, sometimes getting no reading. They were repro coils, probablly Chinese made, so I just got nos Honda ones.

Also going to fix a leaky valve cover thanks to Kyle (Chewbacca) for helping me out with a replacement!



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[mrbreeze]

First off....wanna say that your bike looks great! Clean and tidy. First thing I would do is check the connector I was talking about.....the one that branches off to the power for the coils. Make sure you have 12v on each wire to the coil and that it doesn't fluctuate when you wiggle other wires around. Could also come from bucket, kill switch, etc. like Cal & Scott are talking about. I know it sucks!! Intermittents do because they are harder to trace. Checking for loose, dirty connections and wiggling are the best things you can do. If you have a good wiring diagram it can help you to follow everything in the circuit that could be causing the problem. Checking for continuity will tell you if the path of electricity is complete but won't tell you if there is a short. You are checking point A to point B. If everything is good you will have continuity.You could have continuity but if there was a short it could only be a dead short or an intermittent. Its a little hard for me to explain but if you do some research you can find illustrations that explain it better. Look for something about making meter tests. You don't want your meter set on volts when you are testing resistance or continuity and you don't want any voltage present in the circuit. What I think you need to do is test for resistance from the battery cable to the power wires on the coils. Set the meter for ohms and disconnect the pos cable from the battery. Connect one test lead to the cable and the other to the 2-3 power wire. See if the reading fluctuates when you wiggle the harness or even when you turn the handle bars back and forth. I just reread this and saw something. When you are doing this test you have to have the key on or you won't have a complete path from bat. cable to coil.
That's enough to digest for now.
Different topic.....in your picture is a good shot of the frame kit. I'm getting ready to install mine and am kind of unclear where exactly to cut the tubes. I made the right side front cut and stopped there. I'm concerned about the left side where the ignition switch mounts. My cut .....measured from the top of the tube....is 1&3/4" from the down tube. Is this distance going to foul the ignition switch on the left side? I guess what I would really like to know is the distance yours is cut from the down tube on the left side and a close up pic of the mounted ignition switch would be cool. Yours looks longer than 1&3/4 from the down tube.

[Davez134]

Different topic.....in your picture is a good shot of the frame kit. I'm getting ready to install mine and am kind of unclear where exactly to cut the tubes. I made the right side front cut and stopped there. I'm concerned about the left side where the ignition switch mounts. My cut .....measured from the top of the tube....is 1&3/4" from the down tube. Is this distance going to foul the ignition switch on the left side? I guess what I would really like to know is the distance yours is cut from the down tube on the left side and a close up pic of the mounted ignition switch would be cool. Yours looks longer than 1&3/4 from the down tube.

Thanks for the info. I do have a good wiring diagram, will research and test all wires. I have time, I'm off work on paternity with my 3 week old son, so I'll just put him next to me and test away!

I cut front frame rails 3.5 inches from where the top of the tube meets the downtube. Pretty much what the instructions that came with my kit said. I learned to weld, I can learn wiring now haha.



Sorry about the bad lighting, hope you can see what you need.


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[mrbreeze]

Yeah....that's perfect. I think my concern was this.....looking down at it from the top I thought it would be sticking out too far for the cylinder to clear but after looking again I think by the time the valve cover and head is removed there is still enough room for the cylinder to come up and clear the studs sticking up. I can't think of any problem having the right side at 1.75" and the left at 3.5. Still leaves room for the ignition switch. One other thing....do the parts where they join get turned to one side or the other? I can't see the whole thing coming up to remove. Seems it would have to pull out to the left or right side when unbolted from the frame. I'm just trying to get it straight in my mind before I resume cutting.
Gordon or anybody reading this.....feel free to chime in.

[Davez134]

So, while I was in there I replaced cam cover, checked all wiring, nos honda coils, turned key, and blew the fuse. I need a drink and a nap!

[70CB750]

Time to step back from the bike 

[Davez134]

Time to step back from the bike 

Stepping away did me good. Found the problem easily this morning. When making final connections, i mixed up the ground and power wires coming from Pamco unit.  I have spark to the plugs now finally!

[scottly]

If you blew the fuse, it means your original poor connection was indeed fixed.

[Davez134]

I was very thorough and went through every connection, never found anything obvious. But all are clean/sealed now. She's a strong runner again. 60 degrees tomorrow too