Hey Gang... Found one problem. I still have the weak spark problem.
I changed the points, a primary coil, and retimed it. Checked all connections, but come up with weak sparks. Do you think my external coils are the culprits? I've tried all past posts on condensors, and electrical conections. But still produce weak sparks. How do I check external coils, other than buying new ones?
Coils can go bad or get weak.
Ground connnections on the coils can also go bad.
It could also be the plug wires or caps.
Try this first...
Switch the red and white on the bottom of the external coils around and see if the problem moves to the other cylinder.
If it does than the probelm is on the stator.
However if the weak spark is still on the same cylinder than the probelm is with the coil,wire, cap or sparkplug itself.
You can check the external coils with an ohm meter. The reads should be the same on either coil.
Same goes for the plug wires. An ohm meter may shead light on your issue.
Thanks for your reply Todd. My ohm meter showed low resistance on the plug wires (after I changed them), the coils also, switched coil wires ( same weak sparks), disconnected connector to ignition switch (still weak)! Lol. What grounds should I check, and where would they be. How should I prepare them as well?
The external coils are actually grounded to the engine via the mounting hardware on the CCW engines.
Hence only one input wire on the primary side (red or white).
So you should remove both coils and look for rust or corrosion on the coil frame, spacers, washers, nuts ect.
Remove with a small wire brush or emerycloth.
A common area for rust that many miss is the threaded stud that the primary wire(high tension or spark plug cable) screws onto in the hole on the coil body.
Moisture gets under the rubber boot and rusts this threaded pin which causes high resistance and therefore weak spark.
Do you have weak spark on both spark plugs?
If they both appear to be weak, what are you basing the weak diagnosis on?
Keep in mind it only takes a tiny spark to start the burning of the fuel off under compression.
Also check the stator plate ground to the engine itself. This is done with one lead on the engine and the other lead on the stator ground wire.
If this is not zero ohms you will probably have lighting issues as well as spark issues.
Ground is ground any where on the sled whether it is the talight, ignition coil, guages ect.
Grounds readings on an ohm meter should never be more than 0.3 ohms anywhere.
High readings can usually be fixed with cleaning up the mating surfaces of the connectors, mounting points, mounting washers and bonding jumpers.
Some meters do not read very acurate at this low of a resistance so if you have an anolog meter use the lowest scale like Rx1 and zero it.
If you are using a digital meter again use the lowest scale. Most DVOM's do not have a maunal zero but an automatic one.
If you can't trust your meter you can't believe your readings.
A sure check is to buy a high tolerance (5%) 1ohm resistor at Radio Shack or whereever and occasionly check your meters calibratation.
If you are using a $300 Fluke meter exspect it to be dead on the money accurite.
If you have a $7 GB Electric meter not so much.
Remember paint does not conduct electricity once it is dry. If you have a ground wire with a ring terminal attached to a newly restored chassis and reused the original rusty screw to fasten it you may not like the results. Also aluminum rivets on steel sheet metal is the old dissimilar metals electrolylis dilema. Sooner or later that connection is going to devolpe higher resistance. Now I am not saying you need gold plated hardware and terminals. Just know that any ground connection is suspect unless your sled is a trailer queen.
Last time I checked snow was mostly made of water and a wise man once said electicty and water do not mix.
Add to this the cloride in road salt that gets bucked into the ditches by snow plows, the acid rain from China that mixes in with our La Nina or the fallout from that coal burning power plant in the county west of you and you get accelerated corrsion. If you neighbor's dog lifts it leg on your tunnel that is bad too.
Opps, I did it again. Anoth unwarrented rant. Sorry...
Todd thanks million! I own a $50 digital meter! I work on rusted school busses. So with what iknow about them, and all you have said. I'll put it in my girl's garage and start the process of elimination! Thanks again.
Randy
If you haven't already, you might want to try filing the surface of the new points to make sure they are clean, in case something has built up on them while sitting on the parts shelf.
Matt - JDsleds.com Administrator