Firing order

Firing order? It's only a 2 cylinder. :roll:

 

Firing order

Firing order? It's only a 2 cylinder. :roll:

2 cylinders yes 2 coils 4 plugs a coil on each side

 

Re: Firing order

Firing order? It's only a 2 cylinder. :roll:

Yeah, but is it 1 then 2 or 2 then 1?

 

but it has 4 plugs, 2 per head, do they both fire at the same time

 

Yes, both plugs on a cylinder fire at the same time. It seems to me that I've heard (on this forum) that the plugs fire on every stroke too, not just the compression stroke.

 

Yes, the plugs in each cylinder fire simultaneously, and on most models (I think there may be a few very rare exceptions.) they fire on every revolution, not every other. It keeps the ignition simpler to do ti this way, and it doesn't matter if the plugs fire on the exhaust stroke as well as the compression stroke.

--Justin

 

The blue wire goes to the ignition coil for the front cylinder, the yellow wire goes to the rear cylinder, the spark plug wires with the square flat thing goes to the spark plugs sticking straight out, the other wire goes to the plugs that is sticking out at an angle.

That is all you really need to worry about.

 

From the VT1100C/T factory manual:

Firing order: Front- 495 degrees - Rear - 225 degrees - Front -
Cylinder number: Front: #2, Rear: #1

I hope you find the specs on your model a little clearer... Because this is as clear as mud to me...

I thought there was only 360 degrees in a crankshaft rotation...

So they must be saying they are actually firing once every two revolutions..... at 225 degrees and at 495 degrees (360 + 135)....

I may have to draw this to "picture" it... LOL!

Oh, cool, drawing ta circle, 0 and 360 being at the top, mark off 225 degrees and 495 degrees, you get a PEACE SIGN!

Must be why it makes that "puh-ta-to" exhaust noise?

 

Yes, there is only 360 degrees in a rotation, however, there are two rotations in a four stroke sequence, making a total rotation cycle of 720 degrees.

Intake, Compression (360 degrees)
Power, Exhaust (360)

From the specs you listed, the front cylinder fires first at 225 degrees. This means it fires "first".

They call the rear cylinder #1, that is because it actually "leads" the front cylinder (see picture). The rear cylinder is 270 degrees after the front, which makes the firing order make since, 225 + 270 = 495.

Beyond that, it doesn't make since to me. For cylinder #1, spark should happen slightly before TDC. So from my figures, #1 should fire somewhere just before 360 or 720 degrees (when the piston #1 is highest in the cylinder). The ignition timing doesn't make since to me.

 

I figured it out!!!

I thought this was going to keep me up all night!!!

I looked at the factory service manual, and it actually doesn't say that the timing is 225 and 495 degrees. This is what it says verbatum:

Front-225-Rear-495-Front

What it is saying with the 225 and 495 are the degrees between events, which makes perfect since.

Here we go:

Timing at idle is 5 BTDC, but for the ease of everything lets just say that iit is 0 degrees. (timing is relative to engine speed)

0 degrees: Front Cylinder Fires
225 Degrees Rear Cylinder Fires
495Degrees Later,
AKA 720 Total Degrees, Front Cylinder Fires (new cycle)
AKA 2 full rotations,
AKA 0 Degrees,

The spacing seems weird, until the take into account that the pistons are only 90 degrees separated on the crankshaft, which then balances the sequence.

 

1,2,1,2,1,2.... :lol:

 

Y
They call the rear cylinder #1, that is because it actually "leads" the front cylinder (see picture).

The reason they call the rear cylinder #1 is because Honda engines run backwards.

The later model V6's run normal, but Honda engines have always run backwards.

 

Firing

I thought it was 2-1-2-1-2-1 :roll: I figured all the garage engineers would speak up on this and make it a debate. He just asked for the firing order.

 

Re: I figured it out!!!

I thought this was going to keep me up all night!!!

I looked at the factory service manual, and it actually doesn't say that the timing is 225 and 495 degrees. This is what it says verbatum:

Front-225-Rear-495-Front

What it is saying with the 225 and 495 are the degrees between events, which makes perfect since.

Here we go:

Timing at idle is 5 BTDC, but for the ease of everything lets just say that iit is 0 degrees. (timing is relative to engine speed)

0 degrees: Front Cylinder Fires
225 Degrees Rear Cylinder Fires
495Degrees Later,
AKA 720 Total Degrees, Front Cylinder Fires (new cycle)
AKA 2 full rotations,
AKA 0 Degrees,

The spacing seems weird, until the take into account that the pistons are only 90 degrees separated on the crankshaft, which then balances the sequence.

Okay... That makes sense... It's like decoding the Mayan alphabet to come up with 2012! LOL!

 

Y
They call the rear cylinder #1, that is because it actually "leads" the front cylinder (see picture).

The reason they call the rear cylinder #1 is because Honda engines run backwards.

The later model V6's run normal, but Honda engines have always run backwards.

So then the firing order really is 2, 1, 2, 1, 2, 1.... ?

 

Firing order

running backwards? Does that mean you have to put it in reverse to go forward? :? :lol: :lol:

 

Just to add to the confusion, maybe the rear cylinder is number 1 because it is the left cylinder. But when you look at it, the left cylinder looks like the right cylinder because of the chain to drive the overhead cam.
Or is it the other way around :?:

 

It really doesn't matter why they call each cylinder what. It is just for reference. They could call the rear cylinder purple and the front cylinder square, it doesn't matter.

In all actuality, the FSM refers to the cylinders as front and rear 90%+ of the time to avoid confusion.

The majority of engines (automobile) turn clockwise when looked at from the "front" (where the pulleys are). Until the early 2000s, Honda motors turned counter-clockwise. They started phasing those engines out so they could use a wider range of transmissions in their cars. I'm assuming some part of this applies to their motorcycle engines as well.

 

Yes old thread, but fun reading about he 1-2 1-2 firing order chatter that went on.