Author Topic: Can someone actually help me?  (Read 4582 times)

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Offline jonboycox

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Can someone actually help me?
« on: December 02, 2011, 06:20:07 PM »
I post from time to time with limited and vague response. Please give this one some real thought and try to help.
  I am trying to set the timing on a CB400F with points ignition. I have purchased a new timing light. It will strobe on cylinders 2-3, but I cannot get a strobe on 1-4. I have tried it all along the plug wire, I have cleaned the plug wire of oil and dirt, I have followed the arrow for the direction of the plug, I have tried the opposite of the arrow for the direction of the plug. I have tried every trick I have seen posted in the archives of this forum. I cannot get a strobe from either the 1 or 4 spark plug wire. What could the problem be? The bike starts easily and runs on all four. Great idle, decent run up the rpm range.

Offline FuZZie

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Re: Can someone actually help me?
« Reply #1 on: December 02, 2011, 06:27:35 PM »
1 and 4 should be sharing the same coil, you sure it's running well?

Offline bender01

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Re: Can someone actually help me?
« Reply #2 on: December 02, 2011, 06:35:01 PM »
Strobe connection to the battery still solid after moving to 1-4?
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Offline dave500

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Re: Can someone actually help me?
« Reply #3 on: December 02, 2011, 06:38:38 PM »
try and move the pick up closer to the plug,avoid burning the wire on the hot exhaust.

Offline MCRider

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Re: Can someone actually help me?
« Reply #4 on: December 02, 2011, 06:46:17 PM »
Don't mean to sound flippant, but seems you've got a 2 cylinder CB400. 

What could cause this? Both 1 and 4 leads are dead? The 1-4 coil is dead.

I may be missing something else obvious.  So I'm in it to see whats wrong, like you.  ;D
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Offline seanbarney41

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Re: Can someone actually help me?
« Reply #5 on: December 02, 2011, 06:56:38 PM »
...this happened to me before also...tried it again years later with same timing light, coils, and wires and it worked :o...never figured it out...you can set your timing statically with a simple 12v test lamp...
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Offline Kanticoy

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Re: Can someone actually help me?
« Reply #6 on: December 02, 2011, 07:10:03 PM »
That is an interesting problem.  Are all of the header pipes getting equally hot?  Is there fire at the plugs all of the time?  I'm wondering if the 1 and 4 coil is going bad, because as other posters have said, these two cylinders fire off of the same coil.  Points gaps set?  Getting good spark at the points?  Strange.

Offline HondaMan

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Re: Can someone actually help me?
« Reply #7 on: December 02, 2011, 07:18:17 PM »
Something to check with an ohmmeter:
if the plug cap(s) are burned open, like above 11,000 ohms on the CB400F, the spark discharge will be slow enough that the pickup coil in the timing light may not be able to pick it up. The solution then is new plug caps.
See SOHC4shop.com for info about the gadgets I make for these bikes.

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Offline jonboycox

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Re: Can someone actually help me?
« Reply #8 on: December 02, 2011, 08:25:53 PM »
Awesome responses.
 All four cylinders are firing, all the pipes are hot as hell and I have the burns to prove it. The bike starts and runs really well, just not getting strobe to the timing light. I have tried with the tank off to access the entire length of the spark plug wire. The battery connection is totally solid. The plug caps are new NGK's all the way around. Should I check how they are threaded on to the wire? Is it possible to be getting enough current to fire the plug but not register on the inductive pick up? How can I test the ignition coil? Could this be the beginning of a bad coil? Keep it coming boys.

Offline FuZZie

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Re: Can someone actually help me?
« Reply #9 on: December 02, 2011, 08:56:18 PM »
Follow HondaMan's directions and post back, he didn't get that cape for nothing. ;)

Offline HondaMan

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Re: Can someone actually help me?
« Reply #10 on: December 02, 2011, 09:44:00 PM »
The plug caps are new NGK's all the way around. Should I check how they are threaded on to the wire? Is it possible to be getting enough current to fire the plug but not register on the inductive pick up? How can I test the ignition coil? Could this be the beginning of a bad coil?

Which plug caps did you get? The best bet for these bikes is the 5k (5000) ohm version with stock coils, or 10k ohms with Dyna's 3-ohm coils.

Yes, a weakening coil can cause this: you can check for this by opening the gap on a fresh pair of sparkplugs to 3.5mm each and see if the spark will jump that far (plugs resting on the fins) on both plugs at once. If not, the coil may be "slowing down", and usually it then acts up when hot, working OK when cold. Internally, the insulation is then flaking off some of the wires.

Also, give a tug to those wires where they enter the coil. If one comes out, it's done for.
See SOHC4shop.com for info about the gadgets I make for these bikes.

The demons are repulsed when a man does good. Use that.
Blood is thicker than water, but motor oil is thicker yet...so, don't mess with my SOHC4, or I might have to hurt you.
Hondaman's creed: "Bikers are family. Treat them accordingly."

Link to Hondaman Ignition: http://forums.sohc4.net/index.php?topic=67543.0

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Offline Deltarider

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Re: Can someone actually help me?
« Reply #11 on: December 03, 2011, 12:03:58 AM »
Could there been interference with the neighbouring 2 and 3 leads?
Quote
... or 10k ohms with Dyna's 3-ohm coils.
Hondaman, can you shed some light on this?
« Last Edit: December 03, 2011, 12:08:24 AM by Deltarider »
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Offline bryanj

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Re: Can someone actually help me?
« Reply #12 on: December 03, 2011, 12:21:50 AM »
My personal opinion is strobes are a wast of money for the Hondas, get the points gap set at 0.35mm or 14 thou---NOT JUST SOMEWHERE IN THE TOLLERANCE---and set the static timing exactly on the F with a bulb---(N.B. it can take quite a lot of time and perseverance to get BOTH gap AND timing spot on) and the motor will run like a sewing machine---assuming of course that all the other service items are attended to
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Offline dave500

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Re: Can someone actually help me?
« Reply #13 on: December 03, 2011, 12:31:04 AM »
even if you use the most finnesse and evil eye you have setting points on these,the strobe will show up a shortfall which will be so obvious,more so these days i think to the low quality points available now,if its static timed accuratley it will run,,and run well,the strobe light gets it just that little bit more perfect,the hardest thing is marrying up the timing between 1/4 and 2/3,,youll have the gap or dwell correct but still the "sync"between the pairs can be a mongrel to set,you can be sloppy with low rpm engines in this reguard but these little engines spin fast and the less the pair of cylinders fight or lag the better,it results in a smoother running engine that is easier to vacuum sync,giving rise to a better riding experience.
« Last Edit: December 03, 2011, 12:36:30 AM by dave500 »

Offline Scott S

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Re: Can someone actually help me?
« Reply #14 on: December 03, 2011, 03:54:08 AM »
 Did you cuoff a small piece of the plug wire when installing the new caps? Maybe a 1/4" or slightly less, just enough to expose some fresh wire for the caps to screw into.
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Offline becken

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Re: Can someone actually help me?
« Reply #15 on: December 03, 2011, 06:04:57 AM »
Sometimes if you use a separate battery to power your strobe light (not the bike's battery) you will need to run a wire from the negative of the battery used to power the strobe to ground on the bike to make the light function properly.
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Offline jonboycox

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Re: Can someone actually help me?
« Reply #16 on: December 03, 2011, 06:37:12 AM »
I am using the 5k plug caps. I did cut back to fresh wire before twisting them on. I am remembering seeing the wire coming out of the 1-4 coil rotating a little when I reinstalled them. I will try the trick with gaping the plug and seeing if the coil can push hard enough to jump 3.5mm, I suspect this is the culprit, as it is one of the things I had to repair. It looked as if the #1 plug cap had been yanked off in a crash, there was a length of yellow replacement wire threaded on with the wrong ohm plug cap on the end, this lined up with some scratches on the motor. The #4 looked fine however. I will also try to tug on the wires at the base of the coil on 1-4 and see if they are secure.
  Thanks for the best answers I have had so far on this sight.

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Re: Can someone actually help me?
« Reply #17 on: December 03, 2011, 07:35:21 AM »
Have your ohm meter hooked up to the coil while you are doing the pull and tug. If your meter has the buzzer on the low setting you may hear it.

Offline HondaMan

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Re: Can someone actually help me?
« Reply #18 on: December 03, 2011, 01:21:42 PM »
I am using the 5k plug caps. I did cut back to fresh wire before twisting them on. I am remembering seeing the wire coming out of the 1-4 coil rotating a little when I reinstalled them. I will try the trick with gaping the plug and seeing if the coil can push hard enough to jump 3.5mm, I suspect this is the culprit, as it is one of the things I had to repair. It looked as if the #1 plug cap had been yanked off in a crash, there was a length of yellow replacement wire threaded on with the wrong ohm plug cap on the end, this lined up with some scratches on the motor. The #4 looked fine however. I will also try to tug on the wires at the base of the coil on 1-4 and see if they are secure.
  Thanks for the best answers I have had so far on this sight.

If the wire has been replaced, it is junk. The OEM wires are welded to the coil wires inside the coil (before they slip the insulation over it), and are not removable. This might be pointing directly to the problem...
See SOHC4shop.com for info about the gadgets I make for these bikes.

The demons are repulsed when a man does good. Use that.
Blood is thicker than water, but motor oil is thicker yet...so, don't mess with my SOHC4, or I might have to hurt you.
Hondaman's creed: "Bikers are family. Treat them accordingly."

Link to Hondaman Ignition: http://forums.sohc4.net/index.php?topic=67543.0

Link to My CB750 Book: https://www.lulu.com/search?adult_audience_rating=00&page=1&pageSize=10&q=my+cb750+book
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Offline jonboycox

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Re: Can someone actually help me?
« Reply #19 on: December 03, 2011, 01:33:00 PM »
Some resolution at least. The ignition coil is officially dead, no spark from either 1 or 4 plugs.  Coil to wire joints where not in bad condition. Caps where reading right on 5 ohms, but when I reassembled everything I got no starting and only the 2-3 pipes getting warm. I pulled the 1-4 plugs individually, grounded them out on the motor and saw no spark at all.  I think HondaMan hit the nail on the head once again, that coil was going, going then gone. So moving forward, where should I look for new ignition coils. I would like to replace them both, and preferably with something new. Any links to available options would be greatly appreciated!

Offline HondaMan

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Re: Can someone actually help me?
« Reply #20 on: December 03, 2011, 04:00:27 PM »
Some resolution at least. The ignition coil is officially dead, no spark from either 1 or 4 plugs.  Coil to wire joints where not in bad condition. Caps where reading right on 5 ohms, but when I reassembled everything I got no starting and only the 2-3 pipes getting warm. I pulled the 1-4 plugs individually, grounded them out on the motor and saw no spark at all.  I think HondaMan hit the nail on the head once again, that coil was going, going then gone. So moving forward, where should I look for new ignition coils. I would like to replace them both, and preferably with something new. Any links to available options would be greatly appreciated!

Today's version of Honda's own coils are actually much better than the 1970s version. They also give a longer duration spark than any of the aftermarket coils, and are always my first choice on a rebuild for someone, even a racer. The coils are good past 14k RPM.

The other options out there each have issues: the Dyna 5 ohm coils are pretty good, but have a shorter spark duration than stock coils. The Dyna 3 ohm coils make more voltage, but if the plug caps and wiring is good in the bike, there is little or no difference from the voltage change because the duration of the spark is VERY short unless you add some things to those coils. Those 'tings' are: add a series resistor to the power side of each coil, 1 ohm (this is even Dyna's own recommendation for the SOHC4 bikes), and change the plug caps to 10,000 ohms instead of 5,000. These two things together will let the 3 ohm coils generate about 1.1mS spark duration at about 25kV at the plugs, but the stock coils make 1.2 to 1.5mS duration, much better in comparison. The stock coils make about 7500V (7.5kV) spark, but these engines (stock) only need a little over 4kV to fire and run well.

The main advantage of the Dyna coils is in the long run: the wires can be replaced, where the stock coils won't let you change them.
See SOHC4shop.com for info about the gadgets I make for these bikes.

The demons are repulsed when a man does good. Use that.
Blood is thicker than water, but motor oil is thicker yet...so, don't mess with my SOHC4, or I might have to hurt you.
Hondaman's creed: "Bikers are family. Treat them accordingly."

Link to Hondaman Ignition: http://forums.sohc4.net/index.php?topic=67543.0

Link to My CB750 Book: https://www.lulu.com/search?adult_audience_rating=00&page=1&pageSize=10&q=my+cb750+book
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Offline Kanticoy

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Re: Can someone actually help me?
« Reply #21 on: December 03, 2011, 04:11:54 PM »
The GL1000 coils are awesome replacements for our bikes.  With little effort they will fit the stock bracket, they have replaceable leads, and they produce a very nice spark.  I have them on a cb550 and 2 cb400f's with zero problems.

The only modification I had to do was cut off the little plastic surround on the two end grounding/mounting lugs.  Then it bolts right in.


Offline dave500

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Re: Can someone actually help me?
« Reply #22 on: December 03, 2011, 07:27:33 PM »
make sure what ever coils you get the primary resitance is 5ohms,,in your reply i think you meant your caps have 5000 ohms or 5kohms?

Offline cben750f0

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Re: Can someone actually help me?
« Reply #23 on: December 03, 2011, 09:25:27 PM »
The GL1000 coils are awesome replacements for our bikes.  With little effort they will fit the stock bracket, they have replaceable leads, and they produce a very nice spark.  I have them on a cb550 and 2 cb400f's with zero problems.

The only modification I had to do was cut off the little plastic surround on the two end grounding/mounting lugs.  Then it bolts right in.



just remember that the screw on leads will hit the inside of the tank if you dont modify the mount.... had that issue when i fitted them to the F, in the end fitted VF750/1000 coils and all is good.

http://forums.sohc4.net/index.php?topic=48400.0
peace
« Last Edit: December 03, 2011, 09:30:08 PM by cben750f1 »
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Offline bryanj

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Re: Can someone actually help me?
« Reply #24 on: December 03, 2011, 11:44:35 PM »
GL 1000 coils are not 12volt as they run through a ballast resistor on the GL so yes they will give a great spark as they are being over voltaged but who knows for how long
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Offline dave500

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Re: Can someone actually help me?
« Reply #25 on: December 04, 2011, 12:37:46 AM »
do the gl1000 run a 12 volt on crank/start and say 8-10 volts on run via a switchable ballast similar to older cars bryanj?

Offline bryanj

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Re: Can someone actually help me?
« Reply #26 on: December 04, 2011, 06:55:43 AM »
From memory yes Dave, I do have an "executive" to re-buid sometime and at least 2 Honda manuals here so given incentive i could look it up!
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Offline jonboycox

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Re: Can someone actually help me?
« Reply #27 on: December 04, 2011, 07:59:52 PM »
I have an old set of coils from a bin of Honda parts I purchase awhile ago. How can I tell if the coils are from a GL1000? Is there  a part number on the coil to look for? I see one on the posted pic that I will check, but is there any other way to tell? They do look very similar.

Offline Deltarider

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Re: Can someone actually help me?
« Reply #28 on: December 05, 2011, 04:13:09 AM »
Quote
do the gl1000 run a 12 volt on crank/start and say 8-10 volts on run via a switchable ballast similar to older cars bryanj?
Quote
From memory yes Dave, I do have an "executive" to re-buid sometime and at least 2 Honda manuals here so given incentive i could look it up!
Is any of you capable of producing the wiring diagram of that old Goldwing setup? I wonder how much Ohms and how many Watts that resistor is and I suppose there's some diode involved.
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Offline josephus

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Re: Can someone actually help me?
« Reply #29 on: December 19, 2011, 12:19:10 PM »
have you tried stripping some of the outer most rubber off it doesnt seem like it but some of the cheap induction lights have a hard time picking the pulse up. dont strip it to the core just the outer most layer. its just a thought ive had to do this on my own bike.

Offline HondaMan

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Re: Can someone actually help me?
« Reply #30 on: December 19, 2011, 04:56:58 PM »
Quote
do the gl1000 run a 12 volt on crank/start and say 8-10 volts on run via a switchable ballast similar to older cars bryanj?
Quote
From memory yes Dave, I do have an "executive" to re-buid sometime and at least 2 Honda manuals here so given incentive i could look it up!
Is any of you capable of producing the wiring diagram of that old Goldwing setup? I wonder how much Ohms and how many Watts that resistor is and I suppose there's some diode involved.

There is a bypass relay that shunts across the resistor(s) at startup, much like old cars like Chevys, which used the starter solenoid with extra contacts for the purpose. The resistors are between 1.50 and 2.2 ohms on the several Gold Wings I have measured, depending on the year.

Interestingly, some riders have reported better starting when the relay fails, especially with our ethanol-laced fuels. This is likely due to the resistors providing a longer-duration spark by slowing down the discharge decay via the condensor when a resistor is involved. Some old airplanes also did this.
See SOHC4shop.com for info about the gadgets I make for these bikes.

The demons are repulsed when a man does good. Use that.
Blood is thicker than water, but motor oil is thicker yet...so, don't mess with my SOHC4, or I might have to hurt you.
Hondaman's creed: "Bikers are family. Treat them accordingly."

Link to Hondaman Ignition: http://forums.sohc4.net/index.php?topic=67543.0

Link to My CB750 Book: https://www.lulu.com/search?adult_audience_rating=00&page=1&pageSize=10&q=my+cb750+book
Link to My CB500/CB550 Book: https://www.lulu.com/search?sortBy=RELEVANCE&page=1&q=my+cb550+book&pageSize=10&adult_audience_rating=00
Link to website: https://sohc4shop.com/  (Note: no longer at www.SOHC4shop.com, moved off WWW. in 2024).

Offline 78 k550

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Re: Can someone actually help me?
« Reply #31 on: December 19, 2011, 05:14:22 PM »
GL1000 coils are just like the 750's in they cant be changed out, there sealed wire to coil.
The GL1100 you can swap out wires.

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Offline Mainer4

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Re: Can someone actually help me?
« Reply #32 on: December 20, 2011, 07:43:10 AM »
It would be interesting to ohm out the "dead" coil and compare it to the "good" coil.  Have you confirmed that the coil is really bad as opposed to a bad voltage to the coil or loss of ground?  I have experienced both on my 400F at various times.  Definitely sounds like the 1-4 spark voltage was too low to trigger your light, but not low enough to affect engine operation.  Wonder if both plug boots are actually 5K?
In Christ

Offline jonboycox

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Re: Can someone actually help me?
« Reply #33 on: December 27, 2011, 11:13:44 AM »
I checked the plug boots individualy and they where all OK. I am also not %100 that the coils are bad, but the wire powering the coil and the wires leading out to the points all check positive for continuity. I guess the coils I have are for a GL1100 because the wires are replaceable. Since I purchased them with a  bunch of other parts I needed a while ago, the best way for me to check if the coil is indeed bad or not is to just replace and see what happens, not a major operation. Does any one have any tips on installing coils? It seems pretty straight forward aside from carving a bit of plastic so the tank fits back on. Does the positive to negative have any effect? I suppose they should work regardless of which side the power come in from. Usually power should go to the positive terminal I suppose.