Greetings all
im  new to DT ownership and have bought a 1975 DT175B which isn't sparkling 
I have done all the checks for coil ground kill and ignition switches etc but still no spark.
Digging deeper the stator has been replaced as the connector wire colours don't match. It connects as follows 
From stator to main loom
Black to black and white
Red to green and red
Yellow to yellow 
Green to green and yellow 
No blue neutral switch wire present
My question is should it spark given how it is wired ?
And best way to test the stator please ?
Thanks guys
Regards
Dave Burn Sheffield UK 

 from near Salisbury, Dave.

Not a direct answer to your question, sorry, but maybe have a look at Rex's and Vape sites, to see if the whole ignition system has been changed over for one of theirs. If it has, then a further internet search, or a direct request to the company, might produce the wiring set up instructions that you need.

Also, what markings are on the rotor and stator? Here is a link to a new original one in Australia, although the wiring might differ slightly from the one for US bikes.

GENUINE YAMAHA PARTS STATOR ASSEMBLY DT175FA 1974 DT175B 1975 458-81300-10 | eBay

 

Wiring is the same as mine 
my flywheel is marked F140-04408
I'm hunting for resistance figures for the coils on the stator 
I can't find a readable wiring diagram online 
If any one can assist please do
Thanks 

Does the stator have points and condensor?
 

Points and condensor yes
I have spoken to rex speed shop and they do a refurb service at a very reasonable price, worth talking to if anyone is looking for ignition systems 
 

first I see poss of different plate.  Is that the orig magneto on a diff plate? Matched pair? 

as wired, it appears it would likely spark but I don't know what plate you have there. the black wire from stator plate has 3 connections for main harness. The rest are just lights or charging.

key switch, run switch R handlebar, primary side of coil. any of these are grounded and no spark is result.

a quick test I like is to spin over rotor w/drill and watch for arcing at points. when grounded, they won't arc. if they don't arc, unplug harness to localize and try again. If still no arc, check over points/condenser, magneto, woodruff key, etc. nothing wrong w/replacing 50 year points/condenser.

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Black to black and white (primary of coil and also key sw and handlebar kill sw)
Red to green and red (when lights on, sent to white wire, rectified and charges battery)
Yellow to yellow (sent to headlight dimmer sw )
Green to green and yellow (same as green red, but lights off)
No blue neutral switch wire present (ground for instrument light, no affect on spark)

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