Never thought of the "leaving the coil poles in place". On my 360 i just have the ignition coil only. goes ok but ya got me worried now lol. Maybe its trying to gallop down the paddock like horse instead of even pulses. I'll loose sleep now damn it. I'm outa here--getting nothing done today, nearly got something done then came back for another look haha.

We used to remove the coils too... Years ago I read an article someplace that talked about these types of magnetos and how the magnetic fields "balance" between the coils to give better output or something... way over my head... it's only after that article and many years that I noticed what Yamaha did...

For something that looks so simple, the magneto ignition/lighting systems have a lot of engineering in them.

A few pics... These are the points I purchased


To my mind, this measurement is critical - on these points .185" which is .030" less than the originals. Since the gap that results after timing is supposed to be .012" - .015" these points will never open.



This is the failure of the new condenser - it's a mechanical break.



I take it that original Mitsubishi parts are no longer available.

The correct prefix for the early 250 / 360 points is 214 not 218 . These points may have been
incorrectly tagged for DT / RT fitment .
Although the tang has separated from the condensor , if you were still able to solder to the
remaining stub , everything will work fine .

The points BigDog posted from eBay seem to have the Mitsubishi logo stamped in them.

My guess is the OEM Yamaha points you can still get from your dealer will too?

DEET will almost certainly have the correct points and condenser so you could just buy from him.

P.S. The points you received having a 218 prefix as Swoop noticed likely means they are just plain wrong. I just want to caution that measuring only the rubbing block is not reliable. Different brands could have different arm dimensions that require different rubbing block dimensions by design. Overall, the rubbing edge of the rubbing block should be in the identical relative position (which is much harder to measure) but the block itself could have different dimensions.

Swoop56 - yes indeed - my typo. I went back and found my original order for the points. It was an eBay order for NOS part no. 214-81321-20 which specified "DT1 DT2 DT3 RT1 RT2 RT3" without a year stated. For a DT-1B on Partzilla I get 1M1-81321-20. I found and ordered a NOS pair with this number that included a good close-up. In the pic the cam riser on these points looks to be appreciably longer than the points I installed, which clearly don't work.

You're right I could solder the tab back on and might do that. Since I took out the lighting coils I have plenty of space and might install a higher grade component if I can find one.

MarkT - I getcha - certainly true. I'll place old by new and see what I find regarding the geometry. One thing for sure - these are not the points for this bike. With everything off the motor and putting the rotor and stator plate together and lining things up to have the rubbing part over the highest spot on the cam it's not even close to contacting it. It's hard to see in there but with good lighting I can see a significant distance no matter where how I adjust the points.

Lesson learned - check those part numbers very carefully and watch out for claims about a part fitting your machine. And don't assume you've gotten the right part or real part even when you do check.

There are a set of Genuine Yamaha points being listed on Ebay # 292424020199 .
They aren't cheap , but they don't come up often either . I hunted down and bought a few spare sets
for my DT1 B , so I can vouch for their correct fitment .

Thanks Swoop56 - I had just bought NOS points under 1M1-81321-20 but I added the set you identified to my watchlist. I'll know if the ones I purchased don't work in a few days; if the flop I'll order these straight away.

Related question - any reason why the condenser can't be mounted next to the coil? Easier to access and plenty of room.