Engine firing order?

[blueSTormer]

I'm just curious about it. I know the crack is 360 degrees, but do the cylinders in each side fire together or on alternating power strokes.
Thanks to those in the know.

[Scaredy Cat]

Blue,
I kicked myself when I saw your question, cos it's something I thought I would know. When I think about it, I don't even know which cylinder is 1 or 4!
What I don't understand though, is how come a 90 degree V twin (or V4) is "perfectly balanced". Surely a 180 degree engine is more balanced? BTW, I am not a BMW troll, I have smoooooth ST.
Just a theoretical/discussion point before anyone gets upset.... :p:

[JZH]

1-4-3-2

Ciao,

[Gonzo]

Actually, there is no way any 4-cyl 4-stroke engine can be perfectly balanced, no matter which configuration is used. Each has its own problems. This V-4 can be considered as two vertical twins where on each side, the pistons rise together and fire alternately. This makes the power for each side balanced.
However, the V configuration causes imbalance when the front pair or the rear pair are considered, since as a V-twin, the power strokes are very uneven.
The reason we don't feel this imbalance is because of the counterbalance shafts (which really should be called counter IMbalance shafts) which introduce another imbalance calculated to be the same magnitude and opposite in phase to the main imbalance components of the crankshaft.
Clear as mud, yes?
gonzo

[tomS.T]

blueSTormer, 2 and 4 fire together and 1 and 3 fire together. So each coil is firing twice per rotation. 2 fires on compression and 4 fires on exhaust. At least ,this is how my ST is running.

[blueSTormer]

Thanks guys, this is what I thought but needed confirmation. Not that I am ever going to DO anything with this information, but it's nice to know just how the fire is working down there.

[ST1300 Alicia]

blueSTormer, 2 and 4 fire together and 1 and 3 fire together. So each coil is firing twice per rotation. 2 fires on compression and 4 fires on exhaust. At least ,this is how my ST is running.

The COIL PACK may fire both COMPANION cylinders at the same time with one on the compression stroke and one on the exhaust stroke. The exhaust stroke firing however is called waste spark. The only time a cylinder develops power is when it fires at the top of the compression stroke. Cylinders #1 & 3 Are companion cylinders and Cylinders #2 & 4 are companion cylinders. Companion cylinders rise and fall together however their power strokes are 360 crankshaft degrees apart. The camshaft sets the firing order when it sets the timing for the valve opening and closing. What we really have here boy's is two V-Twins in tandem running 360 crank degrees out of time from each other.

[Putt]

Next time someone does a valve check.. See if the companion cylinder valves
are closed when the timing mark is at TDC.. If so, we have a v-4 firing as a
V twin... Honda lists the firing order as 1-4-3-2. 1 at 90deg, 4 at 270
3 at 90 and 2 at 270..... Huh?? if it is firing sequentially, should it not be
1 at 0, 4 at 180, 3 at 360 and 2 at 540 degrees of crankshaft rotation??...
heck, listen to the exhaust... It sure does not sound like a sequentially firing 4
(to me anyway)..

Putt...