1978 GS 400 Ignition w/ CDI wiring diagram

[Mailo]

I have found this file please look it, it seems to be the same ignition system ( at least have the same name oki mps 200) and have the exact wires colors

http://www.pazon.com/files/PDF/HONDACB.pdf

The pulse generator on my bike has 2 wires, one of them go to the Ignition Unit and the other to ground, acording to the file that is wrong and both wires have to go to the IU.

[posplayr]

I'm reluctantly posting this. If that was the correct part number then it seems someone is trying to fire your 2cyl with a 4 cyl setup by getting rid of one of the ignitors and one of the pickups. I posted about 4 cyl timing vs 2 cyc and I think you still need two pickups . Not sure this ever ran on more than 1 cyl.

[tom203]

That PDF file said you needed to use the original or equivalent pickups . It was an interesting read with explanation of how to wire it.

[posplayr]

That PDF file said you needed to use the original or equivalent pickups . It was an interesting read with explanation of how to wire it.

And he only has one.

[Mailo]

I'm reluctantly posting this. If that was the correct part number then it seems someone is trying to fire your 2cyl with a 4 cyl setup by getting rid of one of the ignitors and one of the pickups. I posted about 4 cyl timing vs 2 cyc and I think you still need two pickups . Not sure this ever ran on more than 1 cyl.

The part number is correct, i think the guy who did this addapted this to work on a 2 cyl.
the end of the crank have a washer with two teeth disposed 180 degrees one from other that triggers the sensor ( These are the 2 pick ups? )
now, the only thing that i dont understand is why in my bike only one of the 2 wires that comes out of the sensor goes to the IU and the other goes grownd, when according to the diagram below both of them wires have to go to the IU.

Sin título.jpg


Thanks for your pattience pals!!

[tom203]

The technical specs seem to imply it's just a transistorized ignition module- not cdi- and I was hoping for something exotic like I put on my mustang 45 years ago.

[tom203]

"....now, the only thing that i dont understand is why in my bike only one of the 2 wires that comes out of the sensor goes to the IU and the other goes grownd, when according to the diagram below both of them wires have to go to the IU."

ok, try it ,what have you got to lose ?

[Gorminrider]

Yes, it looks like you have found its secret out.....It's got to fire both coils together but I guess that's ok given the valve timing on this bike? ....hmm.

[Mailo]

Yes, it looks like you have found its secret out.....It's got to fire both coils together but I guess that's ok given the valve timing on this bike? ....hmm.

sorry i didn't understand you

[Mailo]

Sin título3.jpg


Do you think it will work this way if i connect the battery that way?

[Gorminrider]

I have an issue with the diagram itself- The text of the pdf says there's a white wire. But the diagram shows three blues. I assume it's the third blue in your diagram. As it is, you apparently only have its position on the device to indicate which is which.

Having the same colour implies "commonality". It may be the wrong assumption the Previous owner made by Assuming that all the blues were negative polarity and therefore grounded it to be clever. But the previous owner might have been right, for all I know, but following the directions in that case appears to be the same thing....
I would follow the manufacturers instructions...first.

This Electronic Control you have is apparently replacing a single set of points in the original bike with a transistorized version... and supplys pulses to the coils in the same way. My comment merely is saying that the coils fire together . Being a 4 cycle engine,the spark will only have fuel to use on one of these, as the valves allow it....and the valve timing controls the firing order of the cylinders.

Turn the engine over with the starting motor using a good car battery that itself is not connected to a running vehicle with the spark plugs out... and attached to the leads. The threaded/:wrenching" portion is clamped to the engine fins (-grounded, I mean) or anywhere you can hold them securely with a clamping device. You should see them spark.

Make sure both the plugs are connected to their leads and "grounded". Do one at a time if you must to ensure this, by leaving the other connected and threaded into its hole.. I have heard it can be bad for the device to spin the engine and activate the ignition if spark plugs are not connected and grounded, in some cases at least.

[posplayr]

I have an issue with the diagram itself- The text of the pdf says there's a white wire. But the diagram shows three blues. I assume it's the third blue in your diagram. As it is, you apparently only have its position on the device to indicate which is which.

Having the same colour implies "commonality". It may be the wrong assumption the Previous owner made by Assuming that all the blues were negative polarity and therefore grounded it to be clever. But the previous owner might have been right, for all I know, but following the directions in that case appears to be the same thing....
I would follow the manufacturers instructions...first.

This Electronic Control you have is apparently replacing a single set of points in the original bike with a transistorized version... and supplys pulses to the coils in the same way. My comment merely is saying that the coils fire together . Being a 4 cycle engine,the spark will only have fuel to use on one of these, as the valves allow it....and the valve timing controls the firing order of the cylinders.

Turn the engine over with the starting motor using a good car battery that itself is not connected to a running vehicle with the spark plugs out... and attached to the leads. The threaded/:wrenching" portion is clamped to the engine fins (-grounded, I mean) or anywhere you can hold them securely with a clamping device. You should see them spark.

Make sure both the plugs are connected to their leads and "grounded". Do one at a time if you must to ensure this, by leaving the other connected and threaded into its hole.. I have heard it can be bad for the device to spin the engine and activate the ignition if spark plugs are not connected and grounded, in some cases at least.

I soreted this out a while back. Bottom line is that there needs to be a spark every 180 degrees of the crank for 4 cyl or 2 cyl.

Using a single pickup but a double headed rotor will get the pulse each 180 of the crank.

The wasted spark ignitions put both spark plugs in series so they both need to be grounded to get a spark.

Agree to be careful about getting the wire colors correct, other than that the schematic looks reasonable.

http://www.thegsresources.com/_forum/showthread.php?168652-GS-Ignition-Firing-Order-Diagram&highlight=timing

[Mailo]

Thank you all! This week i have midterms in college, so next one ill fix the wiring and tell you if it worked!

[Mailo]

Hello friends! i rewired the ignition as the last picture i posted and it worked! i used provissionaly a Fiat 1500 car coil becouse the one of the bike was broken and also changed the pickup coil too. and i have spark

thanks to you all for the help!

[Gorminrider]

That's excellent, Mailo! Thank you for reporting your progress! It will help others who read this thread for help.