Beta twin spark plug 300cc....

My bet is the drilled the first plug hole in the wrong spot.

Some CZ’s in the ‘70’s had twin plugs also. 

Dad had 1974 Husky Desert master with an etxtra plug, no spark plug lead going to it though.

Many two stroke flat track bikes had an extra hole in the head for a compression release, buddy removed the relase and plugged it with a spark plug, not sure why.

Why not 3 spark plugs?

My dad said they did this so when they were out riding and you fouled a plug you just switched the wire over to the other side and you could keep on truckin. This was in the 70’s also. 

Twin plug heads are a thing in the air cooled Porsche world, helps with detonation I believe 

Arctic Cat/Suzuki 800cc snowmobile engines have 2 spark plugs per cylinder as well. Not sure why, probably emissions related.

Three way can be a lot o fun...

How are the spark plugs positioned and are they both functional at the same time?  Curious, because I remember an engine builder in the past talking about this and  how he said it could be beneficial. 
Also what I find interesting is that the 250 says it uses a 72mm crank vs the 300 uses a 69.9mm crank. Could the 250 crank be dropped into the 300 bottom??? 

My 78 Husqvarna CR390 is the same.   One plug, the primary one, in the middle of the head.  The secondary plug, without a cap or wire attached, off to the left of center.  Primary one fouls, simply unplug it and attached the cap/wire to the secondary plug to get you home.    

According to the article, this carb'd Beta 300 is using two plugs for better ignition (both live), a higher level of combustion and efficiency.  I'm not enough of an engineer to say if it's really that much more efficient combustion or not considering there are plenty of efficient single plug bikes.  Dunno....  like to see the science, and results behind it.   

Alfa Romeo were big on production twin spark engines also. Porsche and Merc and probably others did indeed mess with it too.

Initially it started in an attempt to squeeze additional power and yep avoiding det, but later on the multivalent engines it was almost solely for more efficient combustion - probably with sketchy Italian engine management and relatively strict euro emissions standards 😂

Weird shit putting it on a two stroke, especially considering how well the KTM group two strokes work without this gimmick.

I dont know the reason, but I know they have been racing with it for a few years in the EnduroGP bikes of Brad Freeman.... Whatever it is the reason, it is a proven idea for Beta.

Datsun nissan did this for a little while. I owned one of the little trucks, think it was an 89. Legit had 8 spark plug wires, never ran especially good when I owned it.

Hemi's have 2 spark plugs per cylinder. That was a 'cheap' tune up in my truck. lol 

I'm sure someone is already in the process of getting a one spark plug head to market ,just cause.

Beta needs to double up on crank bearings before spark plugs

I would guess the reason is to speed up the combustion as in a large bore cylinder it takes time for the flame front to travel from the center to the sides which gives the unignited charge more time to heat up and a risk of detonate. 

I can see it now, "Lighter weight, cheaper servicing, less clutter", although it does sound like a win 😂

From that article it sounds like the same as why the hemi in my truck has 16 plugs on an 8 cylinder engine, efficiency in the combustion chamber.

I had a 93 ford ranger 2.3 liter it had 8 plugs I believe they said it was for emissions lol it certainly wasn't for performance it was a sled lol 

My dad had a 71 suzuki tm 400 if I remember correctly it had two plugs only one wire so you could get back to the truck when the first one fouled lol not sure if that was stock or something he did! That damn bike vibrated your feet numb lol

Because one is "beta" than two. 

They've been testing this for I believe the last few years on one of their riders bikes. Nothing new, just new to the production bikes. 

https://www.thumpertalk.com/forums/topic/1330313-brad-freemans-factory-…