Kawasaki Vulcan Forum banner

1 - 20 of 20 Posts

·
Registered
Joined
·
6 Posts
Discussion Starter #1
Hi, new here.
Please tell me which of the 4 plugs are primary.
I just this 96 1500 "D" for my girlfriend.
Thanks
 

·
Registered
Joined
·
6 Posts
Discussion Starter #3
2 cylinders, 4 spark plugs. In some vehicles, some years, for smog reasons, 2 sets of plugs were used. Primary plugs do 99% of the work, the 2nd set were for burning leftover fuel. Hence, cleaner air. I just got this bike for her and I'm trying to work it.
 

·
Registered
Joined
·
11,756 Posts
2 cylinders, 4 spark plugs. In some vehicles, some years, for smog reasons, 2 sets of plugs were used. Primary plugs do 99% of the work, the 2nd set were for burning leftover fuel. Hence, cleaner air. I just got this bike for her and I'm trying to work it.
I have never heard of that. My curiosity is piqued.
Could you give me an example?
 

·
Registered
Joined
·
6 Posts
Discussion Starter #6
only one plug fires on compression stroke, on the other side of motor at the same time a plug is firing on the exhuast stroke for better emissions, totally useless.
06 and other years of Dodge Ram hemi. Some are for smog and some not. Most Mercedes have 2 but the new ones can have 3 or 4 plugs and way too many valves.
Both plugs in the cylinder fire on every revolution, not every other, like in most 4-stroke engines.

The reason they fire on every revolution is for simplicity of the system, not for anything other than that. You just "waste" a spark on the exhaust cycle. Such a system is called a "wasted spark" system.

The reason you have two spark plugs is to create two flame fronts in the cylinder. This is slightly more efficient and allows you to have a different shaped combustion chamber which also adds to overall efficiency.

Personally, I think Honda used 2 plugs per cylinder on the first Shadow (in 1983) because most of the "big" bikes Honda was making at the time were 4 cylinders. A 4 cylinder bike has two coils, each with two spark plugs on it. That gives you 4 spark plugs, one for each cylinder. Instead of designing a new ignition system and coils for the new Shadow, I think they just used the existing ignition modules and coils, and put both spark plugs in the same cylinder. Just my opinion, not based on anything factual I have come across.
 

·
Registered
Joined
·
11,756 Posts
Any day one learns something is a good day, and today I learned something about the Dodge Hemi I did not know.
 

·
Registered
Joined
·
6 Posts
Discussion Starter #8
We should all lean something every day.
If you put two inline spark testers on one cylinder, one each wire, you will see weather it is "wasted" spark or not.
The Vulcan has a "wasted" spark in the USA.
 

·
Premium Member
Joined
·
3,146 Posts
The Vulcan has a "wasted" spark in the USA.
The Vulcan has two coils and four plugs. How can this be if one coil is firing two plugs at he same time? :confused:
 

·
Registered
Joined
·
11,756 Posts
The Vulcan has two coils and four plugs. How can this be if one coil is firing two plugs at he same time? :confused:
The Vulcan uses one coil per cylinder to fire both plugs.
Wasted spark means that the plug fires once for power stroke and once on exhaust stroke.
The reason for this is that spark timing is taken off of crankshaft pickups which will generate a signal every 360 degrees of crankshaft rotation. If they used camshaft timing or a combination of both, spark would only occur once per 720 degrees as it should (aka 900 and 2000).

Many cars used wasted spark ignition with Ford even specifying different plugs depending on coil polarity for a certain cylinder.
 

·
Registered
Joined
·
6 Posts
Discussion Starter #12
One coil fires at TDC for the front cylinder and one fires at TDC for the rear cylinder. One plug connected to each coil is for igniting the fuel vapor at TDC and the other plug is for firing during the exhaust stroke.
 

·
Registered
Joined
·
233 Posts
The Vulcan has two coils and four plugs. How can this be if one coil is firing two plugs at he same time? :confused:
Simple really. Can you plug up more than on device to a power outlet? Like a cord with a splitter. Yet you can power multiple devices at the same time with the same outlet. I guess it would work the same here. Just need to make sure there is enough 'spark'.
 

Attachments

·
Registered
Joined
·
11,756 Posts
How it does that is the current leaves one side of the coil, travels down the plug wire, down the center electrode of the plug, jumps the gap to the ground electrode, through the cylinder head to the ground electrode of the other plug, jumps the gap to the center electrode, up the plug to the ignition wire and over to the other end of the coil. The coil, wires and plugs form a loop.
In this system, there is no ground on the secondary side of the coil.
You can see Ford's thinking by putting the precious metal on the ground side of half of the plugs as the spark is jumping in the opposite direction on these plugs.
 

·
Registered
Joined
·
233 Posts
Simple really. Can you plug up more than on device to a power outlet? Like a cord with a splitter. Yet you can power multiple devices at the same time with the same outlet. I guess it would work the same here. Just need to make sure there is enough 'spark'.
How it does that is the current leaves one side of the coil, travels down the plug wire, down the center electrode of the plug, jumps the gap to the ground electrode, through the cylinder head to the ground electrode of the other plug, jumps the gap to the center electrode, up the plug to the ignition wire and over to the other end of the coil. The coil, wires and plugs form a loop.
In this system, there is no ground on the secondary side of the coil.
You can see Ford's thinking by putting the precious metal on the ground side of half of the plugs as the spark is jumping in the opposite direction on these plugs.
So, maybe it's not as simple as my post??? Seems to me you could just send an electrical impulse down both lines at the same time. Why not?? Just asking.
 

·
Premium Member
Joined
·
3,146 Posts
How it does that is the current leaves one side of the coil, travels down the plug wire, down the center electrode of the plug, jumps the gap to the ground electrode, through the cylinder head to the ground electrode of the other plug, jumps the gap to the center electrode, up the plug to the ignition wire and over to the other end of the coil. The coil, wires and plugs form a loop.
In this system, there is no ground on the secondary side of the coil.
You can see Ford's thinking by putting the precious metal on the ground side of half of the plugs as the spark is jumping in the opposite direction on these plugs.
Ah! Well, there ya go, leaned something new today. I always thought the coils on these motorcycles fired both plugs simultaneously, not in a loop sequence. :surprise:

 

·
Registered
Joined
·
11,756 Posts
They fire together, with the speed of current flow being the limiting factor which is near the speed of light.
 

·
Registered
Joined
·
1,025 Posts
both coils fire every time.
compression and exhaust. every time each piston approaches top dead centre, every thing fires.
makes for a very cheap ignition system and ecu.
The spark on the exhaust has no effect on engine performance, therefore its a wasted spark.
 
1 - 20 of 20 Posts
Top