Twin spark ignitions were used on YZ465 factory MX bikes. Currently used on factory Beta world enduro championship team bikes. Works very well, especially where fuels of low calorific value are being used. The cost of converting a single spark CDI system is low, as it's a simple matter of fitting a dual lead coil.

Twin spark system on a TY175 motor, makes starting much easier, low speed running is improved, and when cylinders which have been modified to increase transfer flow are being used, over rev is slightly better.

Here is a supplier of ignitions for TY175 (and many other bikes), which are low cost, and very reliable:
www.ohtokc.com/

Some Chinese made carbs such as Nibbi are directly comparable to Japanese carbs, costing twice as much, all carbs are easy to tune, and genuine Keihin parts fit. Nibbi US can be found here: nibbiracing.com/en-gb

The tuning guides for the various Nibbi carbs struck me as very well done, and should be helpful for anyone without much knowledge of jetting/tuning.

Found video of TY twin spark ignition being tested if anyone is interested:https://imgur.com/a/gji3JHz


imgur.com/Ac396MSimgur.com/Ac396MS

Random aside on dual plugs; the last larger Suzuki snowmobile engines (800cc and 1000cc twins used from 2007-2017) had two plugs per cylinder. They did it to help with emissions at idle as turbulence is too low for clean combustion. No power gain, but they don't foul plugs between the dual plugs, fuel injection and the oil pump all (mostly) working like a charm.

Like SNEEZLES61I too had an '86 Nissan 4x4 pu with a NAPS-Z engine and can confirm it did not help with power, with that 2.4l making a whopping 106hp, climbing hills was a leisure activity at best. The aforementioned Suzuki .8l makes ~160hp, but isn't that part of why we love two strokes?

I also had a 1982 Nissian truck 2 wheel drive with the z22 engine that had 2 spark plugs per cylinder. It was a good engine but was not speedy.

MarkT very good honest and factual write up I read it 3 times no snakeoil here Thanks 

So I`ve read all the posts, bottom line I use period after market parts. The stock 74-75 mx175 top end is good as it gets combined with a close ratio gear box, my 30mm short barrel mikuni is from a 76 mx125c. It`s all about the right combination light weight and suspension. So I have a 200 pound bike with a VanTech leading link front end and Curnutt shocks on both ends and close to 30 hp up against over 300 pound machines with about the same hp. Guess what.

You won I hope!
Sneezles61

Is the leading link front end lighter than telescopic forks?

6 pounds lighter.

That sounds very effective. Is it made from Ti and Magnesium?

Won a few.