Only for the technically minded

It's a perfectly valid point, though.

The order could be: 12, 12, 12, 12 IYSWIM (ie. both cylinders firing together).

Could also be 2,1 - especially important to know if it has an uneven firing cycle like my old bike did - 270 degree crank.

Out of interest, any idea why a 270 degree crank would be preferable to 180? I think I'll have a Google...

Si

Honda also uses a 360 cycle too - both pistons are in the same position, just one cycle apart.

That seems the most logical for a 2-cyl 4-stroke engine, it will probably give the smoothest gait, assuming an inline engine.

Maybe his 270 degree crank belongs to a 90deg V engine?

The idea was to make a parallel twin feel and sound like a V-twin.

There's supposedly a traction advantage for a bike, in that there's 2 power pulses close together and then a gap to allow the rear tyre to regain some grip, IYSWIM.

I think it was quite common on British bikes to have identical firing cycles on 2-cyl bikes, it gave the characteristic bike thumping sound. Maybe is was to simplify the ignition mechanism or some other reason? But it gave a lot of vibration of course.

Unlikely

especially important to know if it has an uneven

I don't think it was. Every (twin) Brit bike I had anything to do with had one up one down.

Steve

Are you sure about that? - it was the Japs who did the 180 degree firing cycle - old Brit. bikes were famous for firing both pistons at the same time.

I'll give you that, I tangled myself up there :-))

Steve

The one's I'm thinking of are, yes. It was used a lot in the Honda 2 cyl. cars and vans from the 70's and 80's.

Dunno, I've not seen a strange angled crank, but certainly they exist.

That is there to stop you firing it up in reverse.... ;-)

Smooth power delivery but a horrible thing to balance. Suzuki tend to have them 180 degrees out - easy to balance but lumpy power delivery from idle. I've ridden both and prefer the Suzuki - much more smooth at speed.

My father's Triumphs, (Bonneville and Speed Twin) fired alternatly but the pistons rose and fell together.

I've only ever ridden a CB400N twin, and I honestly couldn't remember what layout that was. It was a rough old thing anyway.

The one's I have in mind are indeed used in cars, they were fitted in the old N and Z model Hondas of the 70's, both as 360cc air cooled and a