GS300L: Replacing a malfunctioning CDI box
 

Hello,
Last year I purchased a 1982 Suzuki GS300L and just recently the CDI box stopped firing on the left side. Here is a link to the model history: http://www.suzukicycles.org/GS-series/GS300L.shtml

Does anyone have a solution? (i.e., CDI box from another motorcycle with similar engine or replace the ignition system.)

Thank you for your help.

82 gs300l
 

I have one recently purchased with same problem. Looking at all the other Suzuki twins of that era, GR650, GS 450, etc., they all use the same wiring configurations and same ignition system. I have purchased a new module from overseas and expect it within a few weeks. In the mean time, i have corrected a problem with the wiring system in the vicinity of the voltage regulator and ignitor box. The negative (black / white) wire is a bit wimpy to transfer all the voltage in that area without heating up. It will benefit from at least a direct connection with the battery terminal. I changed out about a 6" section of that wire with a larger gage, equipped it with plug in connectors to the various other negative wires, and connected it directly to the negative battery terminal. Should help a lot.

Gs300l
 

Well new box is installed. Good thing they warn one about ensuring the voltage regulator is doing the right thing. The new electronics are quite sensitive to unregulated voltage, apparently. Bike started fine, but the voltage output rose from what should have been no more than 15 volts to up to 17 volts. No wonder the original ignitor box failed. New rectifier / regulator box coming now too. Oh well. Once I purchased the little bike, there was no turning back. Good thing it did not cost me a fortune to start with. Later...

Hmm if you can still find the correct cdi for you bike that would be the easiest and fastest solution. Or else you may need to install a aftermarket cdi that can be tuned with your needs.

Where did you buy the new cdi box?

captkerk did the motor ran efficiently after installing the new cdi?

GS300L ignition
 

I got the ignition from an outfit in Bree, Belgium, called Horsepower Ignition. (HPI | Horse Power Ignition)
Yes the firing problem was repaired. What I did find right away though is that they cautioned the user of the new component to ensure that the regulator was working ok and did not allow more than 15 vDC to contact the ignition module. The bike when started did run ok and initial output was 14 vDC but as soon as it revved up it went to 17 vDC The regulator was obviously pooched too. (likely the cause of the failure) So bought one of them quite inexpensively on this continent from of a distributor in Quebec, (Motovan.com), who got it from Electrosport Industries in Irvine California. (Electrosport.com). perfect.
Now all I have to do is figure out why I am getting gasoline coming out of the intake throat of the right side carb.
Checked float levels and gasoline level in float bowls already. Cannot see anything there yet. A bit more checking...
Pete

Wow cool... Many thanks for your review and reply!

I had a delay in my tinkering. Had to move. Slowly getting set up again and will tackle the little Suzuki further soon. I think that due to the age of the bike, one of the carb floats may have become "gas logged" and likely does not act on the float needle valve as forcefully as needed. I checked needle valves and seats. They look ok and stop fluid when closed. More in a week or two.

What part numbers did you order from Belgium?

These old mitsubishi cdi boxes had 2 problems. Moisture and cracking solder points. 1st thing you need to try is to remove the cdi box and place it in a pre heated oven at 275° for 15 minutes. This will bake off any moisture inside without damaging anything. Next, if the bike runs great, seal up any cracks or vent holes. If it is still not running good you can repair it by gingerly splitting the case with a hacksaw and re soldering any cracked solder points. I know its tedious work but its worth it.once inside the box, you will encounter a gel coating that can be removed with acetone, make sure to use gloves and eye protection and let it soak gel side down in a 1/2" of acetone. After 8 hours or so, you should be able to gently pick chunks of gel away and expose the back side of the circuit board and solder points

Many thanks Bob for the suggestions. I have the same bike as the original post, a 1982 Suzuki GS300L, and the same issue, a failed CDI box. It's discontinued and hard to find, so I'll open it up and see if I'm able to repair it. Fingers crossed!