Is this a Coil Problem?

[brobbed]

Hi All,
I'm not getting any spark on #3 & #4 plug. I am suspecting the left coil. i have continuity on both wires and using inductive timing lite there's no power in those wires. a little backround....i've updated my coolant to the evans waterless, afterwhich i smelled antifreeze. so i hosed down with water the radiator and areas from topside like rite side fork and all the wires got wet. Smell ended up being a bad rad. cap, First test ride after that my wing ran perfect 1st block, idle was 1000 rpm, 2nd block bogged down to 2 cylinders, idle 400 rpm, next block then went to full power, then half power and so on. so the problem is intermittent. at the left coil i'm getting 12v pos. side and ground neg. side. still no spark #3-#4. A friend gave me a set of used gl1200 coils. I extended pos. bl/ylw wire to used coil, than ran neg. to frame, then connected #3 #4 plug wires and layed this coil on air cleaner opening....result...no spark! Then tried running 12v pos side to battery...result...no spark. Then repeated this with the 2nd used coil with same result. I'm trying to avoid changing coil cause it's a big job. I still think it's a lose wire somewhere. Has this ever happened to anyone else? Changing coolant has never been so much trouble. any suggestions?

[mikee]

well did you figure your problem out yet? when that happened to me ,i was on a ride out where no man lives ,so no help, managed to limp home!took off the top cover and took out the air box to gain access to all the wiring! found bad connections,and the pick up plug was about to disconnect it self,causing an intermittent miss fire and then no fire,cleaned all the connections and plugged in all the plugs, and all runns great,i found wiring is the bigest problem! with my 85GL-I,

hope this helps, just mikee :d

[seabee]

I would start with the simple things first. Trace out all the wiring and connectors to make sure nothing came loose like mentioned above. Do you have a Haynes or other service manual to show you how to test the coils for resistance? Another thought, how old are the spark plugs? You can try swapping the plugs from side to side.

[brobbed]

thanks mikee and seabee, not to sure what a pick up plug is. but will do the clean connects thing. it kingda makes sense cause my hand was pushing alot of wires working in the radiator/fork area, plus adding water too.
i have manuals but don't really know resistance to good.

[seabee]

The manual will tell you where and how to check the coils. It will also tell you a range of what the ohm's readings should be. If you don't have a digital volt meter you can get the cheap one at harbor freight. It's a good thing to have when working on the bike.

[bs175dths]

I, too, suspect loose/dirty connections.

Try this:
One at a time, remove the wires going to the coils, clean and inspect them and then reconnect.
Removing and reconnecting should take some effort. If little or no effort is required, that connector is a loose fit on the coil terminal and needs to be made a snugger fit.
After all connections have been removed, cleaned, inspected, and reconnected, run the bike again.
Did that work?

If not, try this:
Connect the used coils from your friend without removing the coils on your bike, just disconnect the wires from the bike coils and connect them to your friend’s coils. (assuming the friends coils are good)
Run the bike again.
If that doesn’t work, switch the wires of the coils on the bike. Draw a schematic of the wire connections before removing anything so you can put it back the way it was.
The left coil will now operate what the right coil used to operate. The idea here is to get the problem to move.
If after the wire switching, #1 and #2 cylinders do not work, then it is not the coil, but the wire coming from the pulse generator.
It may also be one of the pulse generators!

I found this information on this site:
To measure the coil resistance:
Measure the secondary coil resistance with the spark plug caps and wires connected to the coil:
Total Secondary Resistance: 24 +/- 3.9 K Ohms

If the total secondary resistance is not within specification, unscrew the spark plug cap resistor retainers, and remove the resistors and springs from the caps.

Measure the secondary coil resistance, without the resistors.
Secondary Coil Resistance: 14 +/- 1.4 K Ohms

Measure the resistance of each resistor.
Secondary Resistor Resistance: 5 +/- 1.25 K Ohms

Note: unless the high tension leads (the wires from the coils to the spark plugs) have been updated, the leads may be 25 or more years old! That rubber and wire core is dry and brittle. When they are moved as when to remove the carburetor assembly, or route throttle/enriching cables or even to service antifreeze, they can fracture or break. When the motor is at idle, it may run fine. Add some vibration and the break or fracture can become an open, causing intermittent spark at the spark plug.
They may also have some fractures is the rubber insulation causing leakage which will result in a weaker spark at the plug.

If the opportunity arises, run the bike at night with the shelter removed. This is the easiest way to see if either your coils or high tension leads are leaking…… you should see arcing taking place.

You could test the individual coils this way too:
With the high tension lead attached to the coil and a spark plug attached to the high tension lead, point the spark plug gap so you can see it, ground the metal part of the spark plug wire, ground the negative side of the coil, touch 12V to the positive side of the coil for a moment, then disconnect it. If all the parts can function, there should be a spark at the spark plug and you will hear a ‘click’.

Hope this helps.....

~O)

[SIR tricky]

Before you do the above, a quick check on the pulse generators, it sure sounds like it could be. 3& 4 cylinder on my bike were not sparking, it was the PG's

Check them out cold.

If they check out then do all the checks in the previous post, if the above checks out then change the PG's

If it isnt them you will have a spare set, you will need them eventually

Also the pulse generator can check out OK cold and still be bad. Mine was reading open on one of the pg's yet would start and run for many hours only to refuse to start (Occasionally)

[brobbed]

thanks all,
i think i may have fixed the problem. i water hosed out the radiator area and hosed down on radiator from rite side of fork to remove the anti freeze odor. so i cleaned all connections in the rite fork area and the last 2 days i've ran good. i still haven't found pulse gen. plug to clean, but they must be in that area somewhere. also according to manual the harness u-shaped grommet is on top of crankcase. that could have leaked water into pulse gens. and by now the use and belt movement may have dried up the problem. the anti freeze smell is still there and today i hosed the radiator area only from the front. that didn't stop the smell either.
thanks again,
rob