• Required reading for all forum users!!!

    Welcome!
    Register to access the full functionality of the GSResources forum. Until you register and activate your account you will not have full forum access, nor will you be able to post or reply to messages.

    A note to new registrants...
    All new forum registrations must be activated via email before you have full access to the forum.

    A Special Note about Email accounts!
    DO NOT SIGN UP USING hotmail, outlook, gmx, sbcglobal, att, bellsouth or email.com. They delete our forum signup emails.

    A note to old forum members...
    I receive numerous requests from people who can no longer log in because their accounts were deleted. As mentioned in the forum FAQ, user accounts are deleted if you haven't logged in for the past 6 months. If you can't log in, then create a new forum account. If you don't get an error message, then check your email account for an activation message. If you get a message stating that the email address is already in use, then your account still exists so follow the instructions in the forum FAQ for resetting your password.

    Have you forgotten your password or have a new email address? Then read the forum FAQ for details on how to reset it.

    Any email requests for "can't log in anymore" problems or "lost my password" problems will be deleted. Read the forum FAQ and follow the instructions there - that's what we have one for...

  • Returning Visitors

    If you are a returning visitor who never received your confirmation email, then odds are your email provider is blockinig emails from our server. The only thing that can be done to get around this is you will have to try creating another forum account using an email address from another domain.

    If you are a returning visitor to the forum and can't log in using your old forum name and password but used to be able to then chances are your account is deleted. Purges of the databases are done regularly. You will have to create a new forum account and you should be all set.

Coil voltage question

willie

willie

Forum Mentor
Past Site Supporter
Had a strange problem yesterday. I started my GK after installing a new battery. It stalled after a minute or so of running on the choke. Took awhile to get it started again. Not normal. When it did start, it was running on #2&3 cylinders. I pulled #4 plug and cranked it over. Sparking but not a strong spark. Cleaned the plugs and it ran on all 4 but 1 & 3 pipes weren't as hot as 2&3. FWIW, I checked voltage to the coils. Here's my question....not only what would cause the problem I just described but also why would there be voltage (11.8 volts) on both the + & - terminals of the coil for cyl.s 1&4 when the ignition was turned on? There is 11.8 volts on just the + terminal of the other coil when the ignition is turned on. I can't believe the coil just happened to fail at that moment when its been running great before yesterday.
Thanks in advance.
Willie
 
If the engine stops with the points open, you will get battery voltage on both sides of the coil. The points or electronic Ign. will ground one side of the coild only when they are closed. The problem with 1-4 could be the coil, wiring, or your points / electronic trigger.
 
if you were to turn the engine over with the key and ignition "ON& RUN"
the positive side stays hot constant and the negative will alternate or turn on and off as the pick up or points opening and closing with every crank revolution

wet wires any where? loose wires? clean contacts. if there is a spark but it is weak and things were fine before the battery swap re check every thing you did last to the bike. it is probably something simple. like resistance/looseness in a connection on the secondary side of the coil, coil to the points = pick up plate to brain box =or brain box to coil connection.
 
Thanks for the advice. I agree that looking at the last thing I did is the wisest route to take when troubleshooting. The bike has factory electronic ignition so point position isn't an issue. I checked all connections everywhere imaginable and all is fine.
Today I tried cranking it. It just won't fire at all. Pulled all plugs and checked for spark. Every plug is firing fine although the 2 outboard cylinders are slightly weaker than the 2 inners. I'm surprised it didn't run on the 2 cylinders that have a healthy spark.
Is there any way that timing could have jumped? I didn't mess with it but when there isn't even a pop while cranking I have to wonder what the h*ll is going on. Whats really got me stumped is that it was starting and idling beautifully up till this happened. Its as though the handlebar kill switch is in the OFF position but I even traced those wires and they're fine.
Please offer more suggestions.
Willie in TN
 
Thimbles full of advice

Thimbles full of advice

Hi Mr. willie,

I'll take a stab in the dark. Was your new battery fully charged when you installed it? Do you think you may be having charging issues now? Does your r/r output give you 13.5-14.5 volts DC at the battery? I'm just speculating that a weak battery and a weak charging system will give you lousy spark, maybe not enough to run right. Have you tried push starting it? Try disconnecting the headlight fuse to take that drain off the charging system.

After I replaced my r/r and stator my lights were much brighter and my bike ran better because it was getting a full spark. Please take the comments from this nooby with a grain of salt.

Thank you for your indulgence,

BassCliff
 
Thanks BassCliff for your suggestions. I appreciate them all. The battery was fully charged per the instructions that came with it. In fact, I was surprised to read in the instructions that using a Battery Tender to charge the battery prior to use could reduce the battery's life. as to the other comments/suggestions....The r/r output is well within spec at both idle and 5K RPM. I removed the headlight fuse from the very beginning. I agree with you completely re: the added voltage available when that fuse is removed. I didn't try push starting it only because the motor is spinning over very well using the starter. No need to push it.
This really has me stumped.
Thanks again,
Willie
 
I suppose it could be, but this isn't feeling like an electrical problem to me based on everything you've said, even though the last thing you touched was the battery. Sounds more like a fuel problem. Have you checked the gas flow? Are the plugs wet? Are the carburetor bowls full?
 
Ya know, I thought about fuel flow being the culprit since I didn't smell any gas even after I'd cranked it for awhile with the choke on. Like I stated earlier, I pulled all the plugs. They were sooty (from the choke being on the last time it ran) but NOT wet. I then loosened the carb bowl plugs to see if there was any gas in them. Gas came out of each BUT, I didn't see just how much gas was in each. Hmmm, we may be on to something here. I'll check them again tomorrow and see just how much gas is in the bowls. I'm using an auxiliary tank so I'm doubtful that the bowls don't have enough gas.
To be contd.
Thanks ALOT
Willie
 
Start by cleaning the start/run switch. Check for coil voltage, should be the same as battery voltage. If not check for a voltage drop thru the ign switch
 
coil voltage question

coil voltage question

if your using an auxiliary tank,did you plug the vacuum line.
 
I believe I found the cause of the problem. Thanks for the help.
Willie in TN
 
Mr. willie,

Please share your fix. It will add to the collective experience. Thanks!

Thank you for your indulgence,

BassCliff
 
I stated that I believed I had found the cause of the problem. If I'm correct, its embarrassing to admit what it was. But I will.
I turned the valve on to the auxilliary tank and hit the starter button a couple of times today. It fired right up and settled into a smooth idle every time. The cause of the problem...was an air bubble in the fuel line that prevented gas to flow into the carbs. Like I stated up front here, its embarrassing to admit it, but on the other hand doing so could prevent someone else from going thru the same frustration I did.
Thanks again for all the suggestions.
Willie in TN
 
You stated that you were getting 11.8V at the coils? This is a problem in itself!!! Your bike is 12V!!! 12V is a minimum figure!!! you need to trace the power wire to the coils (Orange\white on my GS's) there is a splice in this wire that is a common cause of excess resistance, leading to a voltage drop as described.

Dink
 
Yeah, that issue has been in the back of my mind. I've already cleaned all the connectors. I'm considering installing a relay to activate seperate wires from the battery to the coils as detailed in another thread on the board. I can only wonder if .2 volt will make a difference. None the less, its worth finding out. Thanks for responding.
Willie in TN
 
willie said:
Yeah, that issue has been in the back of my mind. I've already cleaned all the connectors. I'm considering installing a relay to activate seperate wires from the battery to the coils as detailed in another thread on the board. I can only wonder if .2 volt will make a difference. None the less, its worth finding out. Thanks for responding.
Willie in TN
Click to expand...

Yes it will!!! 12 volts is 12 volts, less is surprisingly not:shock:

Dink
 
You must log in or register to reply here.
Back
Top