[rsw81]

Hey Guys,
I've looked in the service manual and did a search on the forum, but can't seem to find the firing sequence on our bikes. Is it 1-2-3-4 or 1-4-2-3?
Thanks,
Rob

 

[lollypop]

it should be 1 & 4 together follow by 2 & 3 together.
tat's how an inline works.
correct me if i'm wrong.

 

[Moldmaker]

1-2-4-3

 

[rsw81]

it should be 1 & 4 together follow by 2 & 3 together.
tat's how an inline works.
correct me if i'm wrong.

Not all inlines fire in the same order, that is why I asked. Some just go sequencially down the block and some do 1-4-2-3. Almost no engine has multiple cylinders firing at the same time as you've implied.

 

[rsw81]

1-2-4-3

Can you please point me to your reference for this? I looked through the service manual and didn't find it.

 

[QldRobbo]

I don't know specifically for the fz6, but nearly all inline fours are actually 1 - 3 - 4 - 2

When 1 is on its firing stroke at tdc, 4 is on its exhaust stroke at tdc, which might be what lollypop was thinking

 

[massimo]

This thread has a good discussion. They came to the same conclusion as Robbo:
http://forums.sportbikes.net/forums/showthread.php?t=364797

 

[rsw81]

This thread has a good discussion. They came to the same conclusion as Robbo:
http://forums.sportbikes.net/forums/showthread.php?t=364797

That thread is exactly why I asked this specific question in the FZ6 forum. The position of the piston and the firing sequence got me all twisted up in my thinking because of those guys. I need a fellow FZ6er to point me in the right direction.

The reason I ask is someone told me in the past the FZ6 was weird in this regard, not sure why though.

 

[QldRobbo]

Well reading that post it sounds like the FZ6 does what I thought it does... So I'll try and explain

I'll asume you understand the workings of a 4 stroke engine, and understand what the 4 different strokes are...

Piston number 1, and piston number 4 are positioned in the cylinder the same way, ie they are both at the top of their stroke at the same time. Piston number 2 and piston number 3 are the same, when 2 is at the top of its stroke, 3 is as well. However, when piston 1 is at the top of its stroke, pistons 2 and 3 are at the bottom of their stroke.

When piston number 1 is at the top of its *compression* stroke, piston number 4 is at the top of its *exhaust* stroke.

Number 1 now needs to spark and ignite the mixture, and because piston 4 is at the top of its exhaust stroke there is no issue with sparking in that cylinder as well. So number 1 and number 4 spark at the same time. This is known as a wasted spark setup. The exact same thing happens when number 4 is at its compression stroke. Number one is at its exhaust stroke, so the same spark fires for both 1 and 4. This means the engine can run fine with 2 coils instead of 4.

Same thing with numbers 2 and 3.

Does that make sense?

 

[QldRobbo]

see flash animation on this page

Just imagine that when number 1 fires, there is also a wasted spark in cylinder 4

Animation of 4 cylinder 4 stroke engine

 

[rsw81]

Well reading that post it sounds like the FZ6 does what I thought it does... So I'll try and explain

I'll asume you understand the workings of a 4 stroke engine, and understand what the 4 different strokes are...

Piston number 1, and piston number 4 are positioned in the cylinder the same way, ie they are both at the top of their stroke at the same time. Piston number 2 and piston number 3 are the same, when 2 is at the top of its stroke, 3 is as well. However, when piston 1 is at the top of its stroke, pistons 2 and 3 are at the bottom of their stroke.

When piston number 1 is at the top of its *compression* stroke, piston number 4 is at the top of its *exhaust* stroke.

Number 1 now needs to spark and ignite the mixture, and because piston 4 is at the top of its exhaust stroke there is no issue with sparking in that cylinder as well. So number 1 and number 4 spark at the same time. This is known as a wasted spark setup. The exact same thing happens when number 4 is at its compression stroke. Number one is at its exhaust stroke, so the same spark fires for both 1 and 4. This means the engine can run fine with 2 coils instead of 4.

Same thing with numbers 2 and 3.

Does that make sense?

Yep, I get this. I appreciate you taking the time to explain this, but I am very versed in the engineering of an engine. Just want to verify the firing order as 1-2-4-3 in the FZ6. Someone once told me it was a big-bang engine (mulitple cylinders firing at the same time) and then someone told me it is a screamer engine (typical engines), hence the question about firing sequence. I am aware that it is a screamer-type now and that there is a wasted-spark.

 

[QldRobbo]

I thought that other post had varified that the firing order was 1-4-3-2

Why do you want the know the firing order anyway

Have you looked in the workshop manual (not owners manual)?

 

[ster1]

it goes like this: "bang bang bang bang..." repeat as necessary

 

[rsw81]

I thought that other post had varified that the firing order was 1-4-3-2

Why do you want the know the firing order anyway

Have you looked in the workshop manual (not owners manual)?

I have a pdf of the full service manual (not owners manual) and did a search for various key terms related to the topic with no results. The only thing that came up even remotely related was the valve adjustment page telling you at what angle each cylinder could be adjusted. The post by Moldmaker stated 1-2-4-3 which is what I inferred from my manual as well. I wanted to confirm with you guys to settle a conversation I was having elsewhere. I'm pretty sure I got the answer I was looking for now, thanks guys.

it goes like this: "bang bang bang bang..." repeat as necessary

:lao nfloor

 

[QldRobbo]

The only thing that came up even remotely related was the valve adjustment page telling you at what angle each cylinder could be adjusted

I just looked and on that very same page in the service manual there is a table showing that the firing sequence is indeed 1-2-4-3, I'm assuming you missed that

 

[rsw81]

I just looked and on that very same page in the service manual there is a table showing that the firing sequence is indeed 1-2-4-3, I'm assuming you missed that

I am looking at page 3-12 which notes that the sequence that you check the valve clearance in is 1-2-4-3, not the firing sequence. As stated previously, in a screamer-style engine these sequences are the same thing. In a big-bang engine these do not always equate as some cylinders fire at the same time.

What page are you looking at?

 

[QldRobbo]

this table (attached) is at the bottom left of 3-12

It is showing the firing order (D is combustion stroke).

 

[rsw81]

this table (attached) is at the bottom left of 3-12

It is showing the firing order (D is combustion stroke).

Bueno, gracias.

 

[QldRobbo]

I knew we'd get there in the end

 

[leorojasma]

Hey Guys,
I've looked in the service manual and did a search on the forum, but can't seem to find the firing sequence on our bikes. Is it 1-2-3-4 or 1-4-2-3?
Thanks,
Rob

The answer is in two parts.

1 First, the FZ6 engine CYLINDER firing order, is 1,2,4,3 as other as mentioned, that makes it a screamer engine, in fact the first Crossplane and in turn big bang engine from Yamaha, was in the Yamaha Racing M1 and in the Yamaha YZF-R1 2019 so on.

2 Now the second part of the answer is, althought the engine is screamer, the cylinder 1 and 4 are linked together on the ignition the same goes for the 2 and 3, so it only has 2 spark ignition coils, i assume that the 4 cylinder spark plug gets activated at the start of the admision time when the 1 cylinder is igniting.

This is in contrast to other bike ignition designs like R6s, althought the engine is the very same, on the R6 you have a ignition coil for every cylinder apart, and on the FZ6 only 2 ignition coils so is simpler and i figure less expensive.

This... makes me thing. Maybe if you change the FZ6 spar plug caps with entire R6 ignition coils for direct ignition and you just link together the coils, it could work no?

Interesting question.