1982 Suzuki GS650L STARTING PROBLEMS!!!

[IanDMacDonald]

'82 Suzuki GS650L

Hey all-

I just purchased the above bike and brought it home on Friday. It was not firing on all cylinders when I brought it home, but, that was okay with me for the time being, as I just had an engine seizure on my newly restored '78 Yamaha XS750E.
Anyways, she still rode well. I changed the handle bars to some Euro bars (chrome), and changed the oil and plugs.
Short story, today, she decided that she was not going to start. I got it going on one or two cylinders for a sec, then she died on me. I swapped the battery out, as for some reason the one I had in it was suddenly dying. I looked at the coils, and they look ugly! I had absolutely no idea what I was doing as far as testing the coils. I went from battery to + terminal on wire hooked upto the coil and got 8+v. Same on other side. How do I know whether my coils are bad? I ordered a pair off ebay just-in-case. But, what if it's the CDI module? How do I know if it's one or the other?

Thanks fellas!

Mac

[Digitus]

First thing I usually do is look at the plugs.
Plugs wet -> electrical/ignition problem
Plugs dry -> no fuel / carb problem

You can also try and spray some brake cleaner into the air intake while starting..if she runs, you prolly have a fuel problem

[mike_of_bbg]

First, welcome.

8V at the coils is too low. Usually that's due to dirty connections, mostly at the ignition switch and the engine cut-off. It can be hard to get those connections thoroughly cleaned and tight, so many of us do a "coil relay mod", which is to use a relay to get a full +12V using a line from the battery to the coils.

BassCliff will be along before long I'm sure with the welcome wagon. He has archived a lot of information on his site, which is here:

http://members.dslextreme.com/users/bikecliff/

And there's a write-up on doing a coil relay mod there.

[mike_of_bbg]

BTW, I'm assuming that your battery is putting out way more than 8V (like ~12+V) when I say 8V is too low.

[Steve]

The good news is that you don't have a "CDI module".

What you do have is an "ignitor". It is just an electronic version of points, nothing more.

Simply measuring 8+ volts at the coils does not really mean that much. What was the voltage at the battery under the same conditions?
Not while the bike is turned off, but turned ON, just like you had it when you measured the coil voltage.

If your battery also measures 8+ volts, I would put my vote for "battery problems". If your battery measures about 11.5 to 12.5, you have problems with the wiring between the battery and the coils.

To do a static test of the coils, unplug them from the bike, measure the resistance between the primary contacts. You should see 3-5 ohms. To measure the secondary side, stick your meter probes up the spark plug caps, you should see 30-35,000 ohms.

.

[mike_of_bbg]

To do a static test of the coils, unplug them from the bike, measure the resistance between the primary contacts. You should see 3-5 ohms. To measure the secondary side, stick your meter probes up the spark plug caps, you should see 30-35,000 ohms.

.

IF one is running stock plug caps on stock coils, then 30-35k is a good measure for the secondary. The recommended NGK replacement caps are only 5k each vs. 10k ohms for the stockers, so subtract 10k from your range if you're running those. Stock coils seem to run about 14k on the secondary copper-copper (caps removed, which is probably the best way to test the secondary; measure the caps separately and trim about 1/4" off of the wires before screwing the caps back on if they're good).

[BassCliff]

Greetings and Salutations!!

Hi Mr. IanDMacDonald,

You are now the proud owner of a 30 year old motorcycle that needs 20 years worth of maintenance. If you go through the maintenance lists in your "mega-welcome" and address every task, you will have a safe, reliable, fine running machine. If you skip any steps or take any shortcuts then you will be left stranded on the side of the road at best, injured or severely killed at worst. So, take your time, do it all properly. Then you and your bike will be insanely happy.

Anyway, let me dump a TON of information on you and share some GS lovin'.

I just stopped by to welcome you to the forum in my own, special way.

If there's anything you'd like to know about the Suzuki GS model bikes, and most others actually, you've come to the right place. There's a lot of knowledge and experience here in the community. Come on in and let me say "HOoooowwwDY!"....

Here is your very own magical, mystical, mythical, mind-expanding "mega-welcome". Please take notice of the "Top 10 Common Issues", "Top 15 Tips For GS Happiness", the Carb Cleanup Series, and the Stator Papers. All of these tasks must be addressed in order to have a safe, reliable machine. This is what NOT to do: Top 10 Newbie Mistakes. Now let me roll out the welcome mat for you...



Please click here for your mega-welcome, chock full of tips, suggestions, links to vendors, and other information. Then feel free to visit my little BikeCliff website where I've been collecting the wisdom of this generous community. Don't forget, we like pictures! Not you, your bike!

Thanks for joining us. Keep us informed. I will put you on my prayer list.

Thank you for your indulgence,

BassCliff

[tom203]

IanDMac said..."I looked at the coils, and they look ugly"

Well, after 30 years, they are dingy, but usually functional. Do what others have said.You need to have about 11 volts to coils at a minimum. The ignitor also shares this positive feed; follow Basscliff's link and scoop a color wiring diagram for this mode, cuz it makes troubleshooting easier.If you don't know or trust the maintenance history of this bike, expect the worst- lots of stuff to check. Fixed up right, these are a joy to ride! Don't go crazy buying stuff until you need them; except for stator (and battery), all the electrics on my bike are original.

[IanDMacDonald]

You guys are Awesome!

I'd have to say, belonging to two other bike forums (XS11, and XS750), this forum has provided me with the best welcome! Thank you!

So, I have not had time to really mess with the bike after she quit on me. I will do some measurements tomorrow after school work to see if what the impedance on the coils are.

On a side note, went to Autozone and picked up a EP-34 Relay for my turn signals. Could not find the relay socket, so I'll just use the female connectors. That was an excellent write-up by the way!

I think I am gonna pull the kill switch off tomorrow and check to make sure all is well with that! I did change the handlebars, so, who knows if that is a problem. They are chrome like the stock ones, so, I doubt it.

The ignitor and coils will be here by Saturday, coming from Oregon. Same seller off Ebay. I think if it's one or the other, I can send whatever one I do not need back to him. I was not too happy to see the Clymer manual telling me to replace the coil if there is any doubt as to whether they are bad! Did not give anymore explanation beyond that! If it was not for this forum, I would not know how to check them. I will try the relay mod as soon as they arrive.

Once again, thank you for your help guys. I hope to bring good news by the close of the weekend if I got her running!

[IanDMacDonald]

Will Test Ignitor and Signal Generator Tomorrow!

Hey-

Went out and checked my coils primary resistance, 4.5 ohms on left, 4.6 on right. However, testing the secondary from plug cap, to plug cap, I got an OL reading on my Fluke meter. Not good?

I am starting to lose patience with this bike! I am really confused with the relay mod write-up, as it looked kind of intimidating. I just hope reading it four or five times, I will understand it better.

I am sick, so, I really do not feel like putzing around with it anymore today. My gut tells me it's something more than the coils, possibly the ignitor or the signal generator. I will test those tomorrow and get a reading. I'm crossing my fingers it's just bad coils!

Thanks.

[mike_of_bbg]

Make sure you're resetting your range to something like 200k ohms or 2 meg ohms. The open reading is likely just a cap or two. The resistors in them are prone to going way high impedance when they fail. The caps unscrew from the wires painlessly enough. Then you can cut off about 1/4" of the wire to expose fresh copper and test from wire-wire (instead of cap-cap). You should get about 14k ohms there. New NGK caps cost about $5 each.

[IanDMacDonald]

Replaced the Coils last night!

So, my day went to waste with the rain, so, I screwed around with the turn signal relay mod, which turned out to be a bust.

After that, I replaced the coils, which I certainly noticed a difference in during starting! Sounded very strong! However, I skipped over everything else, and failed to do any testing, and it bit me in the butt! The bike was only running on two cylinders when it finally started.

I will do all the proper testing with the ignitor, signal generator, etc. to see if I missed anything. After that, a coil relay mod. If she still bogs down, gotta pull the carbs. All day project.