CDI and stator testing

i've got real weak spark on a 1985 XR600R. she's got a new plug and ignition coil so it's down to the CDI and/or stator.

question is, how do i test either unit, or is there a way to know which it is for sure without buying new units?

EDIT - also looking for a parts XR600, running or not


I bet it is the stator going bad. My '87 did the same thing. Replaced it with a unit from for $150 delivered. the early XR's are know to have weak stators.

Now, how to check.....

Remove the seat and find the two wires coming up from the left crankcase cover - they should be black/red (ignition exciter coil) and blue (lighting coil). Using a good digital meter, measure the resistance from the black/red wire and ground. It should be 230-320 ohms. I bet yours reads somewhere around 150 or so.

To check the CDI....without special tools you can't, but you can check all the inputs to the CDI and see if they are within spec. Remove the tank to do these checks.

1) Remove the two connectors to the CDI. You will measure the resistance between the following wires:

2) Check the ignition pulse generator: The resistance between the Blue/Yellow and Green/White should be between 360 - 440 ohms.

3) Ignition coil primary: Blue/yellow and Green 0.1 - 0.3 ohms

4) Ignition coil secondary: Blue/yellow and spark plug cap (remove fromthe spark plug and check where the spark plug makes contact within the cap). You should measure 7,400 - 11,000 ohms.

5) Recheck the resistance from the exciter coil at the CDI (remember to reattach the black/red wire fromthe previous check)- find the Black/Red and Green wires in the CDi connectors - you should have the same 230 - 320 ohms resistance.

If these are all good, then replace the CDI.

Hope this helps.

stevePSD -

that helps a lot. thanks.

BTW, which PSD do you have?


A 2000 F-350 Crew-Cab, Dually, 4x4

good to know. i really like the 7.3 PSD. great engine.

i've got a 93 dodge 3/4 4x4 CTD.


I know this is nearly 12 years old, but I don't believe the facts have changed.  my tests revealed 822Ohms between blk/red wire from stator and grnd.  370 for the pulse generator blu/ylw and grn/wht.  open between the blu/ylw and green and also open between blu/ylw and spark cap.  am I correct in believing my stator and ignition coil are bad?  retested after turning engine over a few times.  this is on 1989 xr600r btw  has weak spark if I kick it over fast with plug out.  very erratic also

I've been looking for this info for 2 months! Lol. Everthing described sounds same as my '93. Hope the measurement are same .

ign coils rarely if ever ohm out on these bikes,,,,,,,anyone that has said different found out it was NOT the coil and was indeed the stator,,,if the CDI fires on an XR600R it is very unlikely the issue,,,,,stator failure is as common on these bikes as dandelions on my neighbours lawn,,, :lol:



thanks so much!  will be ordering a rickystator next week. 

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