Without the red it wouldn't get past pretty much idle. Be like a PW50 Peewee yamy where you start it on the safety switch then flick it to go fast mode. Go & enjoy your ride.

lol - clearly I'm not the brightest crayon in the box re hi-lo rpm speed - of course it wouldn't' be mph

appreciate the clarification how the lo / hi coils act - right now it idles and revs, so I'm going to take RT325's advice, and just ride the thing

when I get to trying to set it up for the street, I'll sort out a proper CDI and clean up the harness.

thank you again!

That's all good. Mark is more onto things like that than me but i only know what i know more from mistakes haha but would be nice to know what changes sometime if you feel like pulling that wire then start it. In the mean time-- enjoy ya ride. Ps the way it's set up could be a good trick for anyone in a similar situation that might be short of cash or can't find the new coil on eBay.

Hello guys,

These are new to me ,"two-speed start coil"
Is there any chance of picture or link for the said Coil and the CDI box that suppose ment for it?

TIA



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1979 DT175 shows it. 1980 doesn't have it if partzilla can be trusted.
www.partzilla.com/catalog/yamaha/motorcy...dt175f/c-d-i-magneto
This pic below would be the box with a red & a brown.
Brown being the main ignition source & Red being the top up for high revs. But i think that without the red plugged in it might start but not get past a missfiring fast idle revs on full throttle.
photos.app.goo.gl/nS9M3H122CzaAu4r7
Could run it minus the high speed coil if you use the right cdi box designed for the single source coil but i'm only going by what i did with out yz490k--long story but i used a scooter cdi box which by memory was a yamaha Jog or similar with i think a black/red which would go to the source brown. Then the white/red is for the little trigger coil & think a black in that bunch goes to the stator black which is earth to the stator plate. Other bunch are orange to the plug coil & a black to the main loom plus & a black/white into the loom which is ignition kill switch & ignition off which kills the spark.
If i'm wrong i'll rely on MarkT to sort me out as think he cleared up any confusion a while back on another post with similar issues.
Simple Yamaha CDI box below
photos.app.goo.gl/3DMY9e6wvkJPfXyB9

which reminds me now that some clever dude had use one of the lighting coil wires to power into the box red i guess because he must've had a fauly high speed coil so topped it up with the lighting charging--one of the wires--so it would run as normal i think. Can't get over that trick.

78 and 79 had 7 wire CDI.  80 on had a 6 wire CDI.  If you have a 7 wire on an 80 bike it is likely the wrong un, the red wire from stator being the small high speed coil.

80 stator does not have high speed Coil, so a 79 cdi will have a spare red.

I will be very interested to find out if you have a 80 stator running a 79 cdi without problems.  It would be very helpful if my high speed coil packed in.

Having said that, it is not the first maybe crossover between models i came across.  The italians were famous for using up their earlier parts bins on later models causing much confusion in past years.

was there any update on this.i have the same problem but not finished restoring bike yet.

Hey ogre, deep regrets on the extra long delay - I did not see your post (must have notifications off on my side ffs).

I ended up leaving the wiring as it was - 79 CDI on an 80, and am using it for trails only at this time. I don't believe any ignition issues or the like, does not miss and will happily go past red line. stock carb with new oem jets (22.5 and 150, third clip down on the needle), and needle valve/seat. several hours on it now, even entered it in a 'vintage enduro' in august - finished, but no threat for the podium lol seems to run and handle way better than a '78 DT125 or 175 I have

drive.google.com/file/d/1evgnF0Z7WauRbcb...9Kn/view?usp=sharing

drive.google.com/file/d/1yELTAIubiYWa8NI...Fjv/view?usp=sharing

Regrets if this is against etique, no affiliation, but this place seems to have new aftermarket CDI's for the 80-81 fwiw
www.rpmmoto.com.au/cdi-module-for-1980-1981-yamaha-dt175

Gosh they're a great little bike, so popular.
Thanks for the pics. What country are you in?.
I'm going to remember that wiring trick substituting topping up the high speed part of the cdi box using the lighting yellow when original high speed fails or is missing due to mix & matching stators & boxes.