Thread: a quick coil question ...

I have a 1980 ct70 .. I bought it used and its been abit of a problem child from the start. Recently I can't get any spark at all,



Here is an overview of the entire story

1 won't start
2 check and set points
3 charge battery
4 key switched on, kill switch on..no spark
5 removed tank,looked at coil and wiring
6 after redoing all fuel line, somehow had spark
7 reassembled with tank and battery bolted in..no spark
8 went through harness front to back fixed every nick in wire
9 removed coil ..roughed up base for ground reinstalled,cleaned other grounds

I just noticed that if I put a test light on the small black wire with white stripe leading to the coil it flashs light when I push the kickstart. however I can't get the spark at the boot, or out of the high currentplug wire either..is the coil junk? Its practically brand new as far as use goes.. very little time on it.

anyhow thanks for any help !

Try a new wire from the coil to a brand new sparkplug. See if that works. With all you have done to it when you finally get it running, you will not have to worry about the things you have replaced or looked at.
Good Luck

this thing is haunted I swear...

Was trying different things, while turning it over..started sparking while I was wiggling the kill switch..so I thought ok thats it...disconnect wires to kill switch inside headlight..no spark, even though I elimated the possibility of grounding? open up switch clean inspect..no spark, take it apart do it over about 5 times its sparking... put it together....sparks on run not on kill. I hook up a gas tank externaly as to not interfere inside bike..NO SPARK, with switch in any position ..

I can't remember if the plug wire removes from the coil ?

My only other guess is maybe it needs new points and condenser. they look ok, The small felt that runs on the lobe inside the flywheel looked pretty used up. Isn't there supposed to be a small amount of lube on the surface for the points rubber to slide on? maybe I should get new parts in there. I can't remember anymore if I replaced them or not. It did seem like I would occasionaly get spark after rechecking the point clearence.

I think I got it sparking 4-5 times then after basically doing nothing to it..it quits?

The basic problem is I forgot where I quit last time, I bought it on ebay from someone local (runs great)....and it never has run great in the 5 years I have been messing with it...

Sounds like either an intermittent short at one of the kill switches (on the bars or in the ignition switch) or an intermittent open somewhere in the harness. You can isolate the ignition system by unplugginng the 4-wire connector at the stator and unplugging the Blk/Wht at the coil and then jumpering the Blk/Wht from the coil to the Blk from the stator. Just a thought.

-kevin

I dont know if this is your problem or not. I bought a z50 that had no spark the problem was he had the condensor grounded out with the center wire ........ worth a look ?

Put in a new set of points and replace that condenser. Make sure all wires are on solid to the condenser after replacing it. You will have spark and the problem will be solved. I have looked into my crystal ball and it shall be so.

I am starting to think and believe its the points/condenser, Last night I rechecked the gap, changed nothing else..and it is sparking.. So I wiggled both the ignition and kill switchs..still sparking, no spark with kill switch off, solid spark with the switchs on.

I have all my parts ordered and soon on the way...

When you replace the points check for rust on the point cam inside the flywheel. A little rust in there will gradually sand your points rubbing block down and you'll be back to no spark.

-kevin

I was having very similar issues with my '72 CT70 and it was just the plug cap was loose. I removed it and reinstalled assuring it was on tight. After the test, I was then very relieved that was the extent of my no spark problem.

Amongst who knows what else... the points and condenser seemed to have solved the spark problem ! I did have some other issues that I think have been messing with me from day one. I might have a non honda coil in this bike, and it was interfering enough with the fuel lines underneath to nearly pinch off the gas, I put a slight bend in the tank exits being sure not to crack anything, and I finally have the clearence for fuel delivery !