Pulse Generator

[dthorntonministries]

OK, a few days ago I started up my 85 Aspy and ran it until the fans came on, just to get a good heat cycle in it. It sat for two days. Yesterday, I tried to start it and NOTHING! Not a single plug was firing. It was spinning over like it had no compression. A compression check said, 1=75, 2=75, 3=65, 4=100, plus there was a strange bump coming up through the air box when it was spinning, but only on one cylinder and only when the plugs were in place. With the plug removed the sound was absent.

I opened the timing belt cover and both belts were snug..BUT.. the right bank cam was one tooth off. I adjusted that, retightened the belts and checked the compression. 1=75, 2=75, 3=75 4=100, but it still had no fire and the sound was still there.

Now, I'm trying to see where the plug fire went. The only things that affect both coils all the time are the Pulse Generator and the Ignition Control Unit. Is there any way to test the Pulse Generator with an ohm meter, what those values might be? With the circuitry in the ICU, there is probably no way to test it.

This bike has 21,000 original miles on it. It will be for sale when it is running again. Can anyone give me what they think is a fair price? It needs tires. When I got the bike the only think attached to the frame was the engine and the upper faring. All else was in boxes! I had to put the rear wheel on just to roll it onto my trailer. It took me four months to repair the rat-chewed wires, rebuild all the brake and clutch cylinders, clean it all up after 8.5 years in a covered shed and get all the parts back on.

Sorry, I wandered away from the pulse generator, didn't I?
Be blessed, DT

[virgilmobile]

Yes the pulse generators can be ohm tested right from the unplugged ignition module..
But first..Turn on the key and see if there is volts on the appropriate wires on that module.
Is the kill switch on?

[dthorntonministries]

Yessir, the kill switch is in he run position. It was the first thing I looked at. Been caught in that before, too.
I have exercised the kill switch while turning engine over and that changed nothing. I was hoping that moving it while turning the engine would make something happen, but, nope. No fire to he plugs.

Tomorrow I will get the pin values on the ICU and see what I can learn about the pulse generators. It seems strange that both coils would stop working, suddenly. If you could send me The values you have for the pulse generator, I'll try to check it out.

Thanks for giving me a kick-start. I was just stuck and couldn't get off high center.
Be blessed, DT

[virgilmobile]

Ok.Key off.Unplug both the plugs to the ignition module.The pulse coils should measure about 1000 ohms.Dont get worried if there not exact.(yet)..
There are 2 of them.Measure between ( Blue and White/blue) and (Yellow and White/ yellow)
While it's unplugged.Measure for 12 volts (key on) between Green and Black/white.
Inspect the plugs for corroded pins.Clean as necessary.
Plug the module back in.
A secondary test of the pulse coils..
With the key on,probe with both leads of your meter each pair of wires mentioned above.
You should read a few tenths of a volt.
Something like 0.25 volts dc.
If it reads above 2 or 3 volts,inspect the plug that feeds the pulse coils.
I hope I have the correct schematic.

[dthorntonministries]

Thank you, Sir. That's just the kind of information I am looking for. I had the PG plug open this afternoon and measured about 14ohms on both pulse coils. My manual suggests about 8ohms, but they were both equal, so I put it back together.

I checked the kill switch with an ohm meter and it shows open and closed. However, I did NOT check it to see if it even had power getting to it. I'll do that tomorrow.

I checked the air gap on the pulse coils and showed about .032".

I spun the engine when I got it all back together but still nothing. Tomorrow is another day.
Thanks again. If you have any further thoughts, please share them.
Be blessed, DT

[virgilmobile]

Darn thing does need electric to run.
Are your pulse generators in the back of the engine or up front?Just so I'm looking at the right bike.
Also you mentioned resistance of 14 ohms...
That sounds more like the ignition coils.I thought the pulse coils were around 1000 ohms?
Where on the bike is this "PG" plug you checked?
I also question the gap..0.32" sounds like spark plug gap.
Pulse coil air gap to the trigger is 0.02"-0.04"

[dthorntonministries]

I have choir Rehearsal tonight, but Thursday morning I'll rerun what I did and make notes. Depending on my "pea-brain" anymore is futile. I am using a Clymer's manual. I let my GL1200 shop manual go with a previous GL1200, never thinking I'd ever have another one.

More on Thursday.
Be blessed, DT

[dthorntonministries]

Ok, it's Friday.
I disconnected the plug that is between the pulse coils and the ICM plug. When I ohmed the two coils one showed a dead short and the other, just over 1000ohms. When I looked at the crankshaft bolt, I noticed that the little wiper that triggers the pulse coil was engaged with one of them. So, I rolled the engine until the little wiper was away from both coils and both coils showed a dead short. This is a puzzle. If the coils are a short, how would the wiper have any effect on the coils.

Next, I removed the plugs so I could see the pistons. I rotated the engine until T1 came up in the timing hole. Number one piston was at TDC. When I looked at the little wiper on the crankshaft, it was almost past the pulse coil. I noticed the wiper had a black spot on the leading end, but can find nothing in the manual about that spot. I'm assuming that is the point when the spark is initiated and charges until it reaches the end of the wiper, which is TDC.

I guess I'm getting to old to figure this out. Pretty bummed out.
I think I'm going to go back to zero and start this process all over again, knowing what I've learned here. If you have any further thoughts, please share them.
I'll be in touch later.
Be blessed, DT

[virgilmobile]

Your on the right track.The coils should have measured the same.The trigger...as it moves past the metal protrusion on the pulse coil simply upsets it's magnetic field (collapsing it) to induce a very small voltage.This would also show up as a small resistance change but not much.Certainly not a short.
Inspect the wiring to the pulse coils.
They should both stay near 1000 ohms as the bike is turned over.

[dthorntonministries]

Well, intermittent seems to be the word of the day.

After getting all the plugs back together. I hit the starter and it busted off immediately, but I didn't run it long, without a radiator. I shut it off and began getting the radiator on and refilled, after which I tried to start it....nothing, just like before. I came back, after taking a short walk in the back yard while pulling the rest of my hair out. AAAaaaahhhhh!! I hate when this happens. It stretches my patience.

I hit the start button and exercised the kill switch and IT STARTED UP...momentarily, then off. I checked out the kill switch and it checked ok. I think I'll jump around the kill switch and see if it runs.

Well, that went nowhere. It seems I have an intermittent gremlin in my scooter. I may have to back out and start ohming out wires to see if I can find it. Thank you so much for all your help. I'll be in touch.
Be blessed, DT

[AZgl1800]

open the Kill Switch, and lift one wire, and place it under the other wire.

this will ensure that the switch cannot possibly be at fault.
then if the starter is intermittent, you can look elsewhere.

Check for full Battery Voltage at the starter terminal when you attempt to start the engine.

If you read full battery ~12.6 volts or more, then the starter brushes are at fault ( most likely )

[dthorntonministries]

Sorry, when I reread my post, I can see why you thought the starter didn't turn.
when I hit the button, the engine spun over but never fired, just like before. My Texas slang gets me in trouble sometimes.
I will put the wires together on the kill switch and try it, just to be sure.
Again, thanks for all the help.
Someone else suggested that I put di-electric grease in all these plugs. You'd think, after all the times I've taken them apart and put them back together the blades would be clean, but, hey!, I'm game to try anything right now.
Later.
Be blessed, DT

[virgilmobile]

Use dielectric grease AFTER the contacts are perfectly clean to keep corrosion at Bay.
Grease won't stop a dead short (0) ohms.Thats wires shorted together.
Touch your leads together to see what the meter shows to see the difference between a dead short and a open connection.
Corrosion won't show as dead short but may show no continuity or open connection.

[dthorntonministries]

Yessir, I understand the difference. 4 years as an Naval Aviation Fire Control Radar Technician has it's advantages. However, that was 51 years ago and I just can't reason through schematics like I did then, so I appreciate your help more than you'll know.

OH, I have another question related to schematics. There are wires which, at the end, have notes like, "to B" or "To e". Can you tell me where those letters go? I think it is referring to a plug that those wires go to, but can't find a legend or diagram of where those plugs might be located.

I had to go to the VA clinic this morning for labs, so I lost the cool part of the day. I'll try to get out there in the morning and see what I can learn.
More later.
Be blessed, DT

[virgilmobile]

The letters refer to it's connection with the same letter on another page.
Here's a little known fact.
If you measure for DC volts across the pulse coil,with the key on it will show a few hundred milivolts.eg 0.25 volts.This would indicate the ignition module is providing bias voltage and it's getting to the coil..If it shows no volts the wires are shorted or disconnected from the ignition module.
Should it show 3 volts dc or above,the connection to the coil is open.

[dthorntonministries]

Ok, this afternoon I finally got my head screwed on straight. Previously, I think it was crossthreaded, if you get my drift.

With the key on, I checked DC across the yellow & Yellow/white set of Pulse coil wires and got 2.73 vdc. The blue, blue/white set showed .188 vdc. Aha!! Now, with the key off, I ohmed the yellow set and got 10Megohms. The blue pair showed .367kohms. According to what you shared with me, the yellow set is open or disconnected. Those wires are probably just too small to try to fix if they are broken somewhere, so I ordered the new pulse generator.

In a phone call, I learned that the pulse coil number was discontinued, but they issued a new number for it, and it worked. My new pulse generator should be at H&W Powersports in Palestine, TX on Friday. You can be certain that, before I install the new ones, I will ohm them both to get a resistance on record.

I still don't follow why one of the two generator coils being bad, causes All four plugs to go dead, since they are totally separate, at least outside. If I keep looking in the shematic, maybe, one day, I'll find something.

Tomorrow I'll start removing the radiator, timing belt covers and getting the old Pulse Coil and whatever else needs to come off.

If you think of anything else, please share it. Have a blessed, DT

[virgilmobile]

The new pulse coils may not have a plug that matches the bike.It may be "flying wire" that you have to solder onto your original plug.
So keep track of which pulse coil goes to what wires.The new ones may not have the same color coded wires on them.
The ignition module biases the pulse coil with a few tenths of a volt..when the trigger wheel passes the pulse coil and collapses the magnetic field , the voltage spikes up to trigger the spark.
The gl1100 uses 2 separate ignition modules.One can fail and the other still spark.
Perhaps because the gl1200 uses a combined ignition module,the bias voltage is split to both pulse coils from one source...loose one and the bias voltage is upset on the other disabling the spark.
When you get the new ones in,measure the bias voltage..I'll bet 38cents that it will be different than the 0.188 volts you have now.
Just random thoughts.Keep us posted.

[madmtnmotors]

I learned that the pulse coil number was discontinued, but they issued a new number for it, and it worked.

What is the new part number?

[Shadowjack]

It's 1100s that have the two small transistor ignition amplifiers--1200s have one big box, and they have a yellow/yellow-white pair and a blue/blue-white pair from the pulsers/points/whatever, just like other four-cylinder Hondas. What you refer to as bias voltage is probably common inside the module, of course, and split down the colored pairs to the pulser pickups.
Any online Honda parts seller has the numbers in the fiche, but in this case (1985) it's GENERATOR ASSY., PULSE (TOYO) [old] 30300-MG9-681 [new] 30300-ML8-680. That's a pulser pair assembly, with a single plug for four wires--no soldering or re-pinning ever on Honda parts.

[virgilmobile]

That's good to know that it's a direct replace for the original part.I like plug and play.

[dthorntonministries]

Thanks Shadowjack and Virgilmobile, for confirming that. Sorry, I've been a little preoccupied the last two days.
Here is a story for the books.

Yesterday morning, I got a call from a friend who wanted to use me lift to load his Honda Shadow into the bed of a 3/4 ton pickup. As you know, my '85 Aspy has been under diagnosis for some time. I would have to take it down so I could help my friend. I lowered the lift, got it down off the center stand. When I began to roll it off the lift, unbeknownst to myself of the other two who were standing nearby, a loop of my shoelace had hooked around a tie-down hook on the lift. As I began to roll it off the lift, my left foot stayed in place because of the shoe lace/tie down hook situation. The Wing continued to roll, my foot did NOT. I couldn't reach the front brake in time to stop the bike, so it rotated the bike over onto it's left side, with my left leg still firmly attached to the lift, which meant me left leg was under the bike as it went over. The other two lifted the bike off my leg and I got up and hobbled around on my left leg, getting the wing out of the way, loading the Shadow on the truck and putting the Wing back on the lift. By this time the leg was beginning to really Scream! My bride of 51 years said, "get in, we're going to the ER." which I obediently did. They found that the ankle was ok as was the total knee replacement parts, but the fibula (the small bone behind the shin bone was fractured. They put me in a splint and we headed for Temple, TX to the VA hospital. By the time we got through the system the Orthopedic clinic was closed.

That was aggravating, but here's the cool part. My brother-in-law was in Temple at Scott & White hospital having his bladder removed because of cancer. My sister didn't even know about the leg yet. I called her to let her know that we were going have to come back the next day. Understand, it is 100 miles from Fairfield to Temple. She invited me to use their motel room as she was going to stay at the hospital with Harold. We not only didn't have to drive home and back but the room was free!! Anyway, I got into the Ortho Clinic at the VA this morning. They showed me the fracture and put me in a boot and crutches for the next three months. It doesn't look like I'll be tinkering on the Wing for a while. My new Pulse coil is supposed to arrive at H&W Powersports in Palestine, tomorrow, so I'll be ready when the leg feels like letting me stand in the boot, without the crutches.

I can't thank you enough for helping me get through the diagnosis. I'll be back with you as soon as I am back on my feet.....er, foot.
Be blessed, DT

[dthorntonministries]

Here's an added note.
When we drove into the driveway I saw my roller table, holding all the tools I had used for the last 4-5 days, still standing in the driveway, beside the motorcycle lift. Nothing had been even touched. Ahh, just another of the blessings of living in a small Texas town. Try that in Houston or Dallas.

Also, over night I received either a phone call or text from, at least, a dozen people just offering prayers for my healing and offering to mow my yard or anything else I might need while I am healing. I love Fairfield, Texas.
Be blessed, DT

[julimike54]

Hope you heal up quickly sir!

[dthorntonministries]

Thank you, Julimike.
Be blessed, DT

[dthorntonministries]

Well, I apologize for taking so long to get back in touch about the Pulse Generator situation.
Even before I was released from wearing the boot on my leg, I cripped out to the lift, raised it up and began again, to remove plastic and covers, on my way back to replacing the Pulse Generator. What a hassle, just to feed two little pairs of wires down through the bottom of nowhere, totally out of sight, working by the braille system.

Finally, I got the thing through the obstacle course, plugged in and now, the question....will it run.

Almost, reluctantly, I lowered the lift far enough to reach the key and start button. Much to my surprise...upon pressing that little button, the mighty GL1200 busted off, like the first day off the assembly line!! There is nothing like the sound of a smooth running engine, no matter what kind.

Some days later, after getting out of the boot altogether, I went out to just listen to it again. Low and Behold, a sound I've never heard from this engine, even after it sat in a shed for over 8 long years. On the right bank, there was the sound of a lifter clicking...very loudly. I let it run for a few minutes to see if it was going to clear up, but it didn't. I shut it down and let it sit for a couple of days, hoping the warmed oil would free up the lifter. It didn't.

So, in my ultimate wisdom, I tried an old trick I learned on an old 1955 Chevy 6 cylinder, back in the day. I drained the oil and replaced it with two quarts of 30 wt. oil and two quarts of Marvel Mystery Oil and cranked it up. After a couple of minutes the sound of the lifter began to go away. Finally, I thought I was home free. Then, I began to hear another noise I've never heard. The sound of metal rubbing on metal. Not something I want to hear after finally getting it running again. Well, I shut it off and that's where it sits, waiting for me to dump the mixture out and put proper oil back in.

I'm going to open the timing chain cover again to be sure things are ok there. If that is ok, then I'll see if the engine will hold together long enough to get some oil wherever that noise was coming from, hoping that will take care of it. Better yet, I'll spin it without starting it, to get the oil pressure up without the pressure on the bearings. I'll get back to you again, afterward and report.

If you have any thoughts, please feel free to post it. Thanks.