[livinlo]

Hello,
I picked up a 68 H3 TO583 002607M. It has run in the past rebuilt the carb and today wanted to get it fired up. The problem is that it seems like the engine has been changed and now has a Coil on it. Can someone lead me to a starting point? I have checked and have juice on the positive side of coil and nothing and spark plug. Not sure how to check the coil properly.
Thanks,
Brent

 

[wyogreen]

Brent, the negative lead from the coil goes to the points. When the points are open, you should read battery on the negative side. When the points are closed, you should read 0 volts. When the points are closed, a magnetic field builds up in the coil. When the points open, the field collapses and the resulting high voltage causes the spark plug to fire. You can check the coil/point operation by putting a voltmeter/test light on the negative side of the coil. The voltmeter/test light should pulse on/off as the points open and close as you crank the engine. If you don't see that, then check the points to make sure they are opening and closing, and that the point gap is right.

Steve

 

[livinlo]

Thanks Steve I will dig into this and let you know what the outcome is I get.
Brent

 

[livinlo]

Steve I did the test you described it does pulse on and off as you stated. Then check with my test light the lead going to the spark plug and nothing. I am stumped any help would be great!
Thanks,
Brent

 

[inspired_metal]

Brent,
With the points cover off, can you see the spark at the points as you turn it over? Perhaps you have a broken or pinched wire at the points or the points cover. Does the plug wire have continuity? If you have power to the points when you turn the key it is going to ground somewhere prior to the plug. I'd check that out before i resort to key switch or other stuff.

 

[wyogreen]

Brent, the wire going to the spark plug should be very high voltage. I'm not entirely sure your test light would take that. You should be able to jump a spark from the wire to ground when you crank over the engine. Don't hold the spark plug wire with your hand, you could get a nasty jolt. If you can't jump a spark, check out the spark plug wire, and the inside of the coil where it plugs in. You could have corrosion inside the coil plug, or the spark wire could be bad. There is also a chance that the coil is bad if the spark plug wire checks out ok. You could just try to substitute a spark plug wire from something else just to see if it fixes your problem.

Steve

 

[sybesma07]

Lol is your gas turned on? Make sure your getting gas to the carb. Pull the line to the carb and stick it in a bottle and crank it over. If your getting crank and no start. Start with seeing if it's getting gas. Then I would go to points and then if it's got enough batterie to fully power the motor. Could always try jump starting it by bypassing the key switch and tap the starter with a jumper cable. Just some easy stupid thoughts we have all over looked.

 

[cubby]

Never have so many been so confused by such a simple system. If you diagram it, a third grader should be able to figure it out but engineers tampered with said diagram, you now need a phd from MIT or a good magic spell. Enough ranting! My guess would be the ignition switch since there was no juice at the positive side of the coil.

 

[livinlo]

Guys,
Thanks for all the pointers.
Kevin I do have juice on the positive side of the coil. When I crank the engine over it is pulse the negative side as well.
Last night I removed the side cover and do not see spark jumping the gap on the points. How to make sure that the push rod is extended the full distance. I am going to get some contact cleaner and clean the points. I cant be this difficult.

 

[cubby]

Brent, I missed your test results on the coil. It's beginning to sound like the condenser or maybe the coil itself.

 

[livinlo]

Guys,
Contact cleaner is a wonderful thing. I took the cover off and gave the points a good healthy spray hooked up the battery and bingo. Smooth running!

 

[drew]

Brent when you get a chance replace the points with Kohler points. Don't let a little thing like that continue to be a problem. If they were that dirty they are usually worth replacing.