FZ6-S2 ABS Fuel/Plugs/Coil issue

WastedWrath

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Hi,
I feel like a complete leech but you guys are the absolute number 1 place to come for these bikes, I've used it for years now; so even if you can't help, thanks.

I have a: 2008 FZ6-S2 ABS
27000 miles, not done valve clearance.
Kept outside, no cover ( I know) in South England weather

Mon 18th Jan
Not used or maintained for a while (covid, perhaps once a week for 30 mins). After 10 minutes, completely dies. Running on 2 cylinders. Showing error code 34 on the screen (afaik this is a coil ignition issue).

Decide to ride it to bike shop, completely lose all power during ride (high rpm).
Get to bike shop, they get it running somehow and show that the coil has gone (sprayed water on headers).
End up replacing the ECU with a used one (burned out, that was why I lost all power)
Replaced the broken coil as well .

Beginning of Feb
When I get it back, take it for two 25 mile rides (working perfectly fine) and then don’t use it for a week. As soon as I start it up I can tell its running on two cylinders again.
Get it recovered to the shop, they change the other coil over.
So at this point both coils had gone on two different ECUs

Middle of Feb
I then do maintenance, replace all spark plugs (gapped to manual spec), new air filter,new oil, oil filter.
Rides smooth and purring for about 300 miles until last week on a hot days ride. Turned the bike off whilst having a break and ignition really struggled to get it started again. Seemed to be ok whilst riding.

Decided to test if it would start again (stupidly in the middle of nowhere) and it would turn over but I wouldn't get started. Managed to push start it however anything above 4k RPM or a heavy twist of the throttle the bike would give no more power and judder somewhat. Felt like two cyclinders were fine and the other two would "activate" when engaging throttle but would sputter.

When idling at lights I had to engage the throttle a little otherwise it would drop down to 500~ rpm.

Managed to get it home and it wouldn't start again. Video of what it sounded like all over the bike and starting it again here:

Today:
I have started it twice in a week and it starts up fine) however I haven't ridden it.
I have charged the battery (was on 12~V and now on 13.5V.)
12.5 with key on and no start, 13.23 bike on and idle.
Checked fuses are all working fine in the fusebox.
Checked for fuel line kinks, nothing I can see.
Idled the bike to 70degC and checked headers temperature with gun. Finding that header 1 and 3 are 190-200 degC and 2 and 4 are 140-160 degC. Not sure if this is normal on a cold to idling bike? video here:

Things I plan on doing:
1. Get Fuel and add in Redex
2. Unseat and seat spark plugs and add dielectric grease on caps
3. Check gapping of spark plugs again
4. Measure resistance of plug caps
5. Swap spark plugs and see if temperature of headers changes
Also plan on follow some pointers from here, here and here

I don’t think (amateur opinion) it will be the coil again or the ECU as they have just been changed (all bought used).
I would really appreciate some opinions on what to do at this time as I am time limited due to moving country in October, I won't be taking the bike and it might not be worth the money (I have time) to get this all checked and possibly not fixed even at a garage. (do people buy bike with these sorts of problems?)

Thanks.
 

Gary in NJ

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Something is wrong with the charging system. The battery should hold around 12.7VDC static and it should read around 14.4 @ 3,000 rpm while under charge from the stator. Even at idle it should be closer to 14VD than 13VDC. It could simply be a bad battery. Can you take to a shop for a load test? You don't need to bring the entire bike, just the battery. If you can't bring the battery to a shop, then use your multimeter. The volatge should remain above 11VDC with the starter engaged.

Also, it sounds like the bike has sat a lot over the last 6-9 months. How fresh is the fuel? If it is 6-9 months old, dump it and top off with fresh fuel. I'd probably add a can of Seafoam too. And while we are talking about the fuel system, we've come to learn that a lot of strange running issues are usually the result of a clogged fuel pump filter. While you are dumping fuel, it's probably worth the effort to inspect the screen on the fuel pump.
 

Motogiro

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I agree with Gary on the voltage, but you did say Idle charging and you've probably been beating the battery so it might not show a good static voltage. The intermittent drop of the 2 cylinders I'm hearing makes me think there is a fuel injector problem with regard to possible blockage or varnish.
As Gary mentioned, old fuel is a concern. If the temp of 1 and 3 are close and temp of 2 and 4 are close I don't think it would be a coil or injector signal problem because the computer controls 1 and 4 together as it controls 2 and 3 together. So the coils and injector are paired as far as control. So I'm thinking a fuel problem.
 

WastedWrath

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Something is wrong with the charging system. The battery should hold around 12.7VDC static and it should read around 14.4 @ 3,000 rpm while under charge from the stator. Even at idle it should be closer to 14VD than 13VDC. It could simply be a bad battery. Can you take to a shop for a load test? You don't need to bring the entire bike, just the battery. If you can't bring the battery to a shop, then use your multimeter. The volatge should remain above 11VDC with the starter engaged.

Also, it sounds like the bike has sat a lot over the last 6-9 months. How fresh is the fuel? If it is 6-9 months old, dump it and top off with fresh fuel. I'd probably add a can of Seafoam too. And while we are talking about the fuel system, we've come to learn that a lot of strange running issues are usually the result of a clogged fuel pump filter. While you are dumping fuel, it's probably worth the effort to inspect the screen on the fuel pump.
I agree with Gary on the voltage, but you did say Idle charging and you've probably been beating the battery so it might not show a good static voltage. The intermittent drop of the 2 cylinders I'm hearing makes me think there is a fuel injector problem with regard to possible blockage or varnish.
As Gary mentioned, old fuel is a concern. If the temp of 1 and 3 are close and temp of 2 and 4 are close I don't think it would be a coil or injector signal problem because the computer controls 1 and 4 together as it controls 2 and 3 together. So the coils and injector are paired as far as control. So I'm thinking a fuel problem.


Thanks for the reply guys.
Battery
The 12.5V reading is when the key is turned to on (fuel pump engage/hud on/daytime side lights on) but bike never actually started which also starts the headlights.
13.5V reading directly from battery when nothing is on.
I will get it to 3000RPM today and report back on the voltage.
The battery is a 3 year old gel battery.

Fuel
The last fuel put in was about a month ago, it was premium and I was essentially empty on fuel then. I have only put half a bottle of redex at the beginning of this issue, Feb~. I live in the UK, would redex be the same effect as seafoam here?
I will get fuel in the next couple of days and put redex in and report back on the outcome. It's my only vehicle so its a bit of a job to sort that out right now.

Thanks!
 

WastedWrath

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Update: apparently I don't have unlimited time so it's taken me a while to do this.

Fuel
I siphoned the fuel from the tank. Had to remove the tank completely, and take out the fuel pump (this was obscenley hard compared to videos/the manual) and i felt like I broke the fuel level meter at one point to get it off but it was fine.

There was some residue in the tank and what I assume was liquid sitting underneath the fuel
Finally got to the fuel pump filter and this was on it:
Wasn't prepared enough so I've just had to try and get as much off the filter as possible:
and clean out the fuel pump casing ( didnt get a before but there was a medium amount of muck here:

Long day.....
https://imgur.com/LZbGHQl

Cleaned out the tank with my hand and sloshed some Redex around the tank and then siphoned that again, seemed to get more stuff out. Filled it up with 10L of fuel and....it started! Even though it was starting before anyway haha.

Testing it

Then, I took it for a ride and it seemed as responsive as it always did. No issues at all with stopping and start until... I let it idle up to 100degC, killed the engine. Same ignition issue as before; not quite getting started. At this point I gave it 1/4 bottle of redex and perhaps by coincidence it started to life when starting. Rode it home (no juddering). Once I got it home, had the same starting issue. Video here.

Got out the multimeter and the values are:

12.70V completely off
12.63 On and idling
13.08 at 3k RPM
13.30 at 4k RPM

Conclusion
So.... Juddering issue seems to be resolved (althought I feel like I didn't ride it long enough to recreate it) but the starting issue still ongoing... so the next step is to try a new battery I guess.

Is that what you guys would suggest? Are these battery readings low enough to cause these issues or should I sell it on to someone else?
 

TownsendsFJR1300

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Your charging system is barely working.

When CRANKING OVER, what does the battery drop to?

I don't think that would be the "starting issue" as you seem to have good cranking speed.

The fuel tank wasn't nearly as bad as I thought.

To help determine on the "crank, no start", when it's doing that (AT THAT TIME ), a spritz of starting fluid/fuel down the throttle bodies would help pin point the issue-
IE, if it then starts, you know you have a fuel issue. If no start, very likely ignition.


Just for yourself, here's video of my bike's charging system. Notice the charge at 1,100, idle (I keep my idle there on purpose) and then up to 4k RPM... Dual low beam headlight mod too.
The battery that was in the bike at the time was being replaced as it was showing signs of failure.

 

trepetti

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Good job on the fuel pump. It can be a little tricky, but you did it, and cleaning the screen is a good thing.

Don't know if this is related to your issues, but I am concerned about the voltage readings.

^^^ Scott beat me AGAIN!!!!! :)

Think of things simply. In order to pass current INTO a battery, it has to be done at a voltage higher than what the battery has. Voltage is electrical 'pressure' and always flows from high to low. So at idle, your 'charging' system is putting out less voltage than the battery... no bueno. There is no charging happening. Scott's video shows the numbers you should be seeing.....
 

WastedWrath

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When CRANKING OVER, what does the battery drop to?
I'll get this reading for you tomorrow, thanks.

Your charging system is barely working.

The fuel tank wasn't nearly as bad as I thought.

Just for yourself, here's video of my bike's charging system. Notice the charge at 1,100, idle (I keep my idle there on purpose) and then up to 4k RPM... Dual low beam headlight mod too.
The battery that was in the bike at the time was being replaced as it was showing signs of failure.

Good job on the fuel pump. It can be a little tricky, but you did it, and cleaning the screen is a good thing.

Don't know if this is related to your issues, but I am concerned about the voltage readings.

Think of things simply. In order to pass current INTO a battery, it has to be done at a voltage higher than what the battery has. Voltage is electrical 'pressure' and always flows from high to low. So at idle, your 'charging' system is putting out less voltage than the battery... no bueno. There is no charging happening. Scott's video shows the numbers you should be seeing.....

This sounds, worrying? I think I understand the charging not happening but I'm not sure of how to resolve that, checking my manual it looks like a pretty intricate internal process and not something I'll be able to swap out for £50?

Thanks again for working with me on this.
 

bigborer

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Check the stator plug (it's below the tank) ASAP.

If it's the plug, that's a fire hazard. Mine could have caught fire- discovered it after the battery discharged and left me stranded.


photo_2020-05-16_14-54-57-jpg.73582
 

WastedWrath

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When CRANKING OVER, what does the battery drop to?

To help determine on the "crank, no start", when it's doing that (AT THAT TIME ), a spritz of starting fluid/fuel down the throttle bodies would help pin point the issue-
IE, if it then starts, you know you have a fuel issue. If no start, very likely ignition.
Think of things simply. In order to pass current INTO a battery, it has to be done at a voltage higher than what the battery has. Voltage is electrical 'pressure' and always flows from high to low. So at idle, your 'charging' system is putting out less voltage than the battery... no bueno. There is no charging happening. Scott's video shows the numbers you should be seeing.....

Ambient temp 22degC

First crank after sitting lowest voltage is: 9.56v.
This idled at 14.00v

Rode it for 15 minutes: 90degC FanOff
Lowest voltage at this start is: 9.2v

Rode it for another 15 minutes to get it HOT: 108degC FanOn
Lowest voltage first start: 9.82v
Video

Second crank: 100C FanON, 9.99v (This sputtered a bit but started)
Video

Third crank: 96C FanOff, 9.91v (Not much of a sputter)
Video

Fourth crank: 95C FanOff, 10.08v (The biggest sputter, really didnt want to start)
Video

So from this, the problem is definitely an improvement even after riding a similar amount of time at similar temperatures.

Does the idle at 14V imply its charging now? could it be a bad battery? (3year old gel that im pretty sure wasn't brand new when i got it)
 

trepetti

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Ambient temp 22degC

First crank after sitting lowest voltage is: 9.56v.
This idled at 14.00v

Rode it for 15 minutes: 90degC FanOff
Lowest voltage at this start is: 9.2v

Rode it for another 15 minutes to get it HOT: 108degC FanOn
Lowest voltage first start: 9.82v
Video

Second crank: 100C FanON, 9.99v (This sputtered a bit but started)
Video

Third crank: 96C FanOff, 9.91v (Not much of a sputter)
Video

Fourth crank: 95C FanOff, 10.08v (The biggest sputter, really didnt want to start)
Video

So from this, the problem is definitely an improvement even after riding a similar amount of time at similar temperatures.

Does the idle at 14V imply its charging now? could it be a bad battery? (3year old gel that im pretty sure wasn't brand new when i got it)

Something just occurred to me..... Read post 225: https://www.600riders.com/threads/vibration-a-cure-for-bad-vibrations-spark-plug-caps.48874/page-12
where I had a starting / sputtering problem caused by excess voltage draw on the circuit that fed both the fuel pump and the cooling fan. It reminded me that this circuit is very sensitive to lower than normal voltage. In my case, I had a healthy battery and charging system that was over taxed due to the fan laboring against an obstruction. In your case, you have low voltage to start with.

Lesson I learned was that is the voltage to the fuel pump is too low, everything will sound on, but there will not be enough fuel pressure to start / sustain the running of the engine.
 
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WastedWrath

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Something just occurred to me..... Read post 225 where I had a starting / sputtering problem caused by excess voltage draw on the circuit that fed both the fuel pump and the cooling fan. It reminded me that this circuit is very sensitive to lower than normal voltage. In my case, I had a healthy battery and charging system that was over taxed due to the fan laboring against an obstruction. In your case, you have low voltage to start with.

Lesson I learned was that is the voltage to the fuel pump is too low, everything will sound on, but there will not be enough fuel pressure to start / sustain the running of the engine.
Having trouble finding post 225, checked your profile and used search and can't find it.

It always seems to start fine first time and subsequent times after its just after riding it for a while and its hot (fan is on or has been on) that the problem is prevalent. I rode it for 30 mins in 20-30mph traffic and stopped and started a couple times just fine. Voltage is 14v during ride all the time pretty much.
 

trepetti

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Having trouble finding post 225, checked your profile and used search and can't find it.

It always seems to start fine first time and subsequent times after its just after riding it for a while and its hot (fan is on or has been on) that the problem is prevalent. I rode it for 30 mins in 20-30mph traffic and stopped and started a couple times just fine. Voltage is 14v during ride all the time pretty much.
... forgot to post the url :)

I just edited my post, take a look now.
 
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