How do I check for spark?

[Stringbean781]

Hello my fellow FZ6 lovers!

Recently my o7 fz6-shg started running rough one morning(rough idle and barely any throttle) and I parked it right away. I did some research and thinking it was running on 2 cylinders, I figured it was spark related. After work that day, I ran it again and it continued to run rough idle dropping, and then it wouldn't start after that. I changed the spark plugs, checked the battery, the coils, plug caps, and crank position sensor(all check out).

(3 months prior) I had gotten the tank repainted and I was afraid the fuel pump went bad after sitting for a month so I changed that last night. The old pump had a bunch of paint chips on the filter and there was some water in the gas tank. I refilled with fresh fuel and it cranks but wont start. I almost sounds like a cylinder is firing, but it could just be the compression noise. I am suspecting that the fuel injectors are clogged, but before I do that, I want to check to make sure all cylinders are sparking. Does anyone have info on how I can test sparking of each cylinder? I can find a tutorial anywhere online. Additionally, any info on removing the fuel injectors would be awesome too! Any help would be greatly appreciated!!!

 

[Gary in NJ]

To answer your question...

1. Remove the spark plugs from the cylinder head.
2. Reinsert the spark plugs into the spark plug caps
3. Rest the ground electrode or thread on the engine head to create a ground path between the plug and the engine
4. Engage the starter and observe if the is a blue spark between the electrode and electrode ground. If the spark is red, the plug should be replaced

Now, with that said...

If you are SURE that all four plugs are good, you don't need to remove the plugs to check for spark. You can follow steps 2-3, using any spark plug that fits the cap.

Some other questions...

Do you hear the fuel pump priming when the key is moved to the run position?
Has this bike been tipped over?
Are you sure that the spark plug caps are secure on the spark plug wires?
When you removed the fuel tank to replace the fuel pump, did you replace the filter assembly?
When you removed the fuel tank to replace the fuel pump, did ensure that the fuel line was reinserted properly?
When you removed the fuel tank to replace the fuel pump, did you accidentally or intentionally disturb the spark plug wires from the coils?

Using a infrared thermometer (which everyone seems to have now) you can check the temperature of each exhaust pipe to check and see if you have a dead cylinder on a running engine. If 3 are at 700-900 degrees about an inch from the flange...and the other is at 100-150...you found the dead cylinder. In the old days before infrared thermometers were available I'd use spit on the tip of my finger to find the dead cylinder....and that worked...but it also removed a few layers of skin. Not recommended.

 

[Stringbean781]

Thanks for your response! Awesome for the step process!! I figured it was that simple, but I didn't want to make any mistakes! I will do that tonight!

I do hear the fuel pump prime.
Yes the bike has been dropped before. I have dropped it twice.
Yes, the fuel pump i bought came with a new filter to attach to the bottom.
If you mean the fuel line outside of the tank; Yes, it gets pressed on and a clip snapped into place.
I don't believe I disturbed the spark plug wires because they are so far from the fuel pump location(on the other side of intake)

I would love to check the exhaust and I should have when it was running for the hour before it quit. Now because it wont start, I doubt it'll get to those temps with just the crank.

 

[trepetti]

To answer your question...

1. Remove the spark plugs from the cylinder head.
2. Reinsert the spark plugs into the spark plug caps
3. Rest the ground electrode or thread on the engine head to create a ground path between the plug and the engine
4. Engage the starter and observe if the is a blue spark between the electrode and electrode ground. If the spark is red, the plug should be replaced

Now, with that said...

If you are SURE that all four plugs are good, you don't need to remove the plugs to check for spark. You can follow steps 2-3, using any spark plug that fits the cap.

Some other questions...

Do you hear the fuel pump priming when the key is moved to the run position?
Has this bike been tipped over?
Are you sure that the spark plug caps are secure on the spark plug wires?
When you removed the fuel tank to replace the fuel pump, did you replace the filter assembly?
When you removed the fuel tank to replace the fuel pump, did ensure that the fuel line was reinserted properly?
When you removed the fuel tank to replace the fuel pump, did you accidentally or intentionally disturb the spark plug wires from the coils?

Using a infrared thermometer (which everyone seems to have now) you can check the temperature of each exhaust pipe to check and see if you have a dead cylinder on a running engine. If 3 are at 700-900 degrees about an inch from the flange...and the other is at 100-150...you found the dead cylinder. In the old days before infrared thermometers were available I'd use spit on the tip of my finger to find the dead cylinder....and that worked...but it also removed a few layers of skin. Not recommended.

If you don't have an IR Thermometer, have a spray bottle with water nearby. Start the bike and periodically mist each exhaust pipe. Once the exhaust comes up to temp, the water will steam off as soon as it hits the pipes. When that starts happening, any dead cylinders will not turn the water to steam.......

 

[Gary in NJ]

Yes the bike has been dropped before. I have dropped it twice.

Was the last drop coincident with the lack of starting? There is a tip-over switch that prevents spark firing after a tip-over.

 

[Gary in NJ]

If you don't have an IR Thermometer, have a spray bottle with water nearby. Start the bike and periodically mist each exhaust pipe. Once the exhaust comes up to temp, the water will steam off as soon as it hits the pipes. When that starts happening, any dead cylinders will not turn the water to steam.......

That is the same principle as spit on the tip of the finger...except the steam on the finger is followed by pain.

 

[Stringbean781]

Was the last drop coincident with the lack of starting? There is a tip-over switch that prevents spark firing after a tip-over.

No, it occurred a month before. I checked the tip sensor in diag mode and it checked out.

 

[TownsendsFJR1300]

As it's NOT running now, you can't check for the header for heat.

Check for spark, as noted above and confirm there is good spark on all 4 plugs.

If there IS good spark, pull out the air filter and while cranking, spritz some fuel, (spray bottle), or starting fluid down the intake. If it kicks, you know there's a fueling issue...

Make sure your battery is fully charged before / especially, doing the spark test.


Plz post back what you find..


.

.

 

[TownsendsFJR1300]

1. Remove the spark plugs from the cylinder head.
2. Reinsert the spark plugs into the spark plug caps
3. Rest the ground electrode or thread on the engine head to create a ground path between the plug and the engine
4. Engage the starter and observe if the is a blue spark between the electrode and electrode ground. If the spark is red, the plug should be replaced

Huh? Typo or?

 

[Gary in NJ]

Huh? Typo or?

From my own personal experience, a blue spark is strong, and a red spark is at the end of its life. It may work...but not for long.

 

[TownsendsFJR1300]

From my own personal experience, a blue spark is strong, and a red spark is at the end of its life. It may work...but not for long.

Interesting... Agreed, a blue spark is strong but I've never seen a red spark, never..

Weak, intermediate, none, never red..

.

 

[trepetti]

That is the same principle as spit on the tip of the finger...except the steam on the finger is followed by pain.

I recall reading somewhere that the spray bottle was invented to eliminate finger pain.....

 

[TownsendsFJR1300]

I recall reading somewhere that the spray bottle was invented to eliminate finger pain.....

Said the 9 fingered man!

 

[Motogiro]

Maybe pull each plug and it may reveal which plug has been running bad. This would also give an opportunity to do a leakdown/compression test to eliminate a miss due to poor compression at the offending cylinder.

 

[trepetti]

Thanks for your response! Awesome for the step process!! I figured it was that simple, but I didn't want to make any mistakes! I will do that tonight!

I do hear the fuel pump prime.
Yes the bike has been dropped before. I have dropped it twice.
Yes, the fuel pump i bought came with a new filter to attach to the bottom.
If you mean the fuel line outside of the tank; Yes, it gets pressed on and a clip snapped into place.
I don't believe I disturbed the spark plug wires because they are so far from the fuel pump location(on the other side of intake)

I would love to check the exhaust and I should have when it was running for the hour before it quit. Now because it wont start, I doubt it'll get to those temps with just the crank.

So I am rereading this, and if it was me, this is how would proceed.

Engines (even modern complicated engines) need only 3 things..... air, fuel, spark. Air is rarely an issue, so start with fuel and spark. If I read this correctly, the bike ran poorly until you replaced the fuel pump, after which it will not run at all. So the problem worsened / changed after the fuel pump replacement.

I would prop up the tank, remove the top of the air box and spray starting ether into each throttle body individually, and crank the bike to see if it starts. If it runs, then you need to focus on the fuel system, if not then its spark.

And remember, it could be BOTH. You may have a bad coil reducing to 2 cylinders, underlying a fuel system issue created with the pump replacement.

Be patient and make only 1 change at a time. All problems can be fixed..

 

[Stringbean781]

As it's NOT running now, you can't check for the header for heat.

Check for spark, as noted above and confirm there is good spark on all 4 plugs.

If there IS good spark, pull out the air filter and while cranking, spritz some fuel, (spray bottle), or starting fluid down the intake. If it kicks, you know there's a fueling issue...

Make sure your battery is fully charged before / especially, doing the spark test.


Plz post back what you find..


.

.

This sounds like a good plan and makes sense to me!! I will try an attempt this today and update with my findings! Thanks for all the responses!!

 

[trepetti]

As it's NOT running now, you can't check for the header for heat.

Check for spark, as noted above and confirm there is good spark on all 4 plugs.

If there IS good spark, pull out the air filter and while cranking, spritz some fuel, (spray bottle), or starting fluid down the intake. If it kicks, you know there's a fueling issue...

Make sure your battery is fully charged before / especially, doing the spark test.


Plz post back what you find..


.

.

....yeah, like Scott said

Sorry for duplicating your idea.... next time I'll read the entire thread before chiming in.....

 

[Gary in NJ]

Engines need only 3 things..... air, fuel, spark.

You missed one....
.....
.....
.....compression

Suck, Squeeze, Bang and Blow.

 

[Stringbean781]

So I was able to get into this morning. With starter fluid sprayed into the intake, it fired up for a few seconds each time! Now next steps are to remove the tank and air box to reach fuel injectors + fuel rail. I plan on sending the injectors to Mr. Injector. Any suggestions for cleaning out the fuel rail etc?

 

[trepetti]

JM2C. For me, step 1 of troubleshooting is to figure out the trouble.

While it is possible that all 4 injectors have failed to a point where none are working, the single point of failure is fuel pump / fuel pressure. Verify your fuel pressure before sending anything out for repair.