2 STROKE WORLD .net

The 2-Stroke Garage => Turning Wrenches => Topic started by: KANDY on January 05, 2022, 09:55:48 AM

Title: 1979 RD400 Daytona Special Ignition Questions
Post by: KANDY on January 05, 2022, 09:55:48 AM
Hi All,

Happy New Year

I am in the process of Building RD400 Daytona Special Canadian Bike. It has CDI Ignition.

All the wiring done all the lights works as it should, No Spark. Found out coil is defective - Secondary resistance is infinite

Could you guys guide me how diagnose to make sure Stator and other related parts are in working order.

While I am waiting on the Ignition Coil(going to use RZ350 Coil), could I be able to test by using 1977 RD400 coil.

Please help out.

Thanks to all
Title: Re: 1979 RD400 Daytona Special Ignition Questions
Post by: rodneya on January 05, 2022, 10:43:31 AM
A coil from a points bike will not work with the CDI ignition.
Im pretty sure the RD350LC stator was the same as the daytona, so you may find more testing info on one of those

Found the LC specs
Title: Re: 1979 RD400 Daytona Special Ignition Questions
Post by: KANDY on January 05, 2022, 12:11:11 PM
Thanks rodney,
Will update after testing.
Title: Re: 1979 RD400 Daytona Special Ignition Questions
Post by: m in sc on January 06, 2022, 05:09:42 PM
hook up a meter to the wire that goes to the coil, and kick it over, should see a spike of ac voltage.
Title: Re: 1979 RD400 Daytona Special Ignition Questions
Post by: 1976RD400C on January 09, 2022, 08:06:44 AM
Here are the resistance values
Ignition coil   primary .33 ohms     secondary  3.5K
Source coil that charges CDI   red to brown 5.3   brown to green  225
Pick up coil  115
Charging stator coils   .4
Title: Re: 1979 RD400 Daytona Special Ignition Questions
Post by: KANDY on January 10, 2022, 08:07:00 PM
This is what I got
Red to Brown = 5.1   
Brown to Green  249
Pick up coil  84
Charging stater coils   .7

Hope this will work.
Waiting for YFZ350 Coil
https://www.ebay.ca/itm/254835446461
Title: Re: 1979 RD400 Daytona Special Ignition Questions
Post by: rodneya on January 10, 2022, 10:26:48 PM
Those cheap Banshee coils can be a headache. A lot of people dont trust them. OEM, Dyna or Nology are the only ones that work reliably and consistently.
Title: Re: 1979 RD400 Daytona Special Ignition Questions
Post by: KANDY on January 18, 2022, 03:59:05 PM
Quote from: m in sc on January 06, 2022, 05:09:42 PM
hook up a meter to the wire that goes to the coil, and kick it over, should see a spike of ac voltage.

I connected the meter on the Orange and Black wires that go to the coil, there was a spike in AC (something like 76, 97,106 while I kick)
But still no spark. Does this spike mean Alternator, Regulator Rectifier and CDI are good.
Please help out.
Title: Re: 1979 RD400 Daytona Special Ignition Questions
Post by: m in sc on January 20, 2022, 10:27:10 AM
if it were me id try another coil. initial assumption is that yes, the rest seems good. also worth doing the same at the ign pickup wire, it should throw a slight voltage spike when kicked over.
Title: Re: 1979 RD400 Daytona Special Ignition Questions
Post by: rodneya on January 20, 2022, 11:39:13 AM
How are you checking spark? Are both leads grounded. If only 1 lead is grounded it will not spark
Title: Re: 1979 RD400 Daytona Special Ignition Questions
Post by: m in sc on January 20, 2022, 10:18:21 PM
yup. BOTH plugs need to be touching ground for them to spark. If one is just 'open' the other one wont spark either. rodneya is correct
Title: Re: 1979 RD400 Daytona Special Ignition Questions
Post by: KANDY on January 21, 2022, 09:12:39 AM
Thanks,
Need to look at the wiring. Flasher is giving trouble.

Both plus were Ground while testing. I will get back to you.

The coil i was using was brand new, the one from the link provided above.
Title: Re: 1979 RD400 Daytona Special Ignition Questions
Post by: KANDY on January 27, 2022, 08:27:41 PM
Renewed all wiring. All lighting works good. But no spark.
I must have checked wrong, There is no spike of AC on Orange and Black Wire going to the Coil primary, when I kick over. But I could see AC spike on the wire which is coming from the pick up White/Red and Blue
New Ignition coil and both Spark plugs were Ground.
Title: Re: 1979 RD400 Daytona Special Ignition Questions
Post by: Striker1423 on January 27, 2022, 09:51:00 PM
Short to ground somewhere along the wire. Check your points for grounding. Broken insulators, misaligned etc.
Title: Re: 1979 RD400 Daytona Special Ignition Questions
Post by: 1976RD400C on January 28, 2022, 08:48:49 AM
I would check for a voltage spike with a meter on the red to brown and then the green to brown wires as you kick it. That will tell you if the source coils that charge the cdi are trying to work. Your ohm readings on those coils seem ok as you previously measured. If you get a reading that they are trying to charge, and the pick up coil seems to be doing it's thing, and the coil is new, then I think you got it down to a bad cdi unit.
Title: Re: 1979 RD400 Daytona Special Ignition Questions
Post by: KANDY on January 28, 2022, 10:01:04 AM
Just Checked. Actually I have here Red, Brown and Black wires. Red to Brown and Black to Brown I saw the spike in AC when Kicked. I guess I should Look for a CDI :bang:
May I know any suggestion on CDI, I mean any compatible. If Someone have a good one Please let me know.
Title: Re: 1979 RD400 Daytona Special Ignition Questions
Post by: 1976RD400C on January 28, 2022, 10:22:14 AM
Does this look like what you got? https://www.ebay.com/itm/331083831960?hash=item4d16225a98:g:GfkAAOxyNo9SpczI
Title: Re: 1979 RD400 Daytona Special Ignition Questions
Post by: KANDY on January 28, 2022, 10:54:56 AM
I think they look similar.
Mine in the pic
Title: Re: 1979 RD400 Daytona Special Ignition Questions
Post by: 1976RD400C on January 28, 2022, 01:01:18 PM
Looks like that's the one you want. It is made by HPI in Belgium.   https://www.hpi.be/item.php?item=CD4402
Title: Re: 1979 RD400 Daytona Special Ignition Questions
Post by: 1976RD400C on January 28, 2022, 01:19:17 PM
I can't see where the black with white stripe wire goes in your diagram but I think that is the shutdown wire so make sure that is not being grounded out at either the key switch or kill switch, or anywhere else after leaving the cdi box before ordering any parts.
Title: Re: 1979 RD400 Daytona Special Ignition Questions
Post by: KANDY on January 28, 2022, 01:39:07 PM
Thanks,
The Black with White stripe wire is going to the Kill switch.
I checked all the input and Output for CDI bunch of wires and found for sure CDI is Faulty.
The conclusion came from Following measurements.

1. Resistance of Black/White to Ground is Infinite when Ignition ON position and Kill Switch RUN position. Resistance is 0 when Ignition OFF or Kill switch OFF position

2. Brown and Red AC Spike while kicking.

3. Brown to Black AC Spike While Kicking

4. Red/White to Black AC Spike While Kicking

5. Orange to Black No AC Spike While Kicking : This means to me that All in puts to CDI are correct but there is no output from CDI to Primery of the coil.

Please correct me if I am Wrong

Going to Order the CDI you Recommended.