Date: 28-03-24  Time: 19:13 pm

Author Topic: Stuttering engine below 4k (FZS600)  (Read 4895 times)

feral kid

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Stuttering engine below 4k (FZS600)
« on: 14 August 2017, 04:35:56 pm »
Hi Everyone, for couple of weeks I've been having a problem with my FZS600 ('02, 40k). The engine stutters below 4000RPMs very badly. Sometimes I can fully open the throttle and it won't accelate for couple of seconds. Sounds really weird too.
I took it to the workshop; the spurk plugs where changed, air filters, ignition pipes, have done 1000 miles since then and the problem persists.
My mechanic told me that he will have to open the engine to check the valves and other stuff, but it's not going to be cheap.
Anyone has a clue what could be the problem?


darrsi

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Re: Stuttering engine below 4k (FZS600)
« Reply #1 on: 14 August 2017, 05:12:15 pm »
Have to start with a TPS check, they cause jerkiness when they're on their way out.
Also make sure your spark plug caps are screwed on to the HT leads properly.
If air filter's been changed and the TPS is showing up okay and in the correct position then my next step would be a carb balance.
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Re: Stuttering engine below 4k (FZS600)
« Reply #2 on: 16 August 2017, 03:22:02 pm »
Have to start with a TPS check, they cause jerkiness when they're on their way out.
Also make sure your spark plug caps are screwed on to the HT leads properly.
If air filter's been changed and the TPS is showing up okay and in the correct position then my next step would be a carb balance.
Thanks Darrsi, I will check it with my mechanic

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Re: Stuttering engine below 4k (FZS600)
« Reply #3 on: 16 August 2017, 07:52:03 pm »
Dirty pilot jets before switching to main jets ???
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Re: Stuttering engine below 4k (FZS600)
« Reply #4 on: 16 August 2017, 08:52:07 pm »
I had this problem, had the wrong plugs in, 9E when they should have been 8E. Ran like a dream for the last 2k so might be worth a look which plugs you have fitted

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darrsi

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Re: Stuttering engine below 4k (FZS600)
« Reply #5 on: 16 August 2017, 09:20:37 pm »
I had this problem, had the wrong plugs in, 9E when they should have been 8E. Ran like a dream for the last 2k so might be worth a look which plugs you have fitted


Shouldn't really matter to be honest, i've tried both with no issues at all and they both also cover the heat range of our climate very easily.
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Re: Stuttering engine below 4k (FZS600)
« Reply #6 on: 16 August 2017, 11:11:12 pm »
Dirty pilot jets before switching to main jets ???


That would have been my guess, ignition is pretty constant (With a few variables) but if it all levels out at 4K and then does not miss a beat I would plump for partially blocked pilots.
Be interesting to know if the stuttering gets worse as the revs climb towards the 4K, before it clears, that would point to partially blocked pilots jets (not necessarily all of them) just one will cause a real power drop not just loosing the 25% but the drag of one lazy pot on the other pots would make it feel more like 50% down.   

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Re: Stuttering engine below 4k (FZS600)
« Reply #7 on: 16 August 2017, 11:14:12 pm »
I'm having the same trouble! Done all the usual checks I'm of the opinion the the tps is on the way out. I'm pretty sure it got some water leaked into it over a heavy weekend here recently.
My next step is to take it off and give it the hair dryer treatment followed by a spray of isopropyl alcohol. If this don't work then I think I'm looking for a replacement sensor- ouch!  :\

The last thing I want to do is much about with the carbs i'm not to confident with them tbh.
« Last Edit: 16 August 2017, 11:16:10 pm by celticdog »
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Re: Stuttering engine below 4k (FZS600)
« Reply #8 on: 16 August 2017, 11:36:15 pm »
I'm having the same trouble! Done all the usual checks I'm of the opinion the the tps is on the way out. I'm pretty sure it got some water leaked into it over a heavy weekend here recently.
My next step is to take it off and give it the hair dryer treatment followed by a spray of isopropyl alcohol. If this don't work then I think I'm looking for a replacement sensor- ouch!  :\

The last thing I want to do is much about with the carbs i'm not to confident with them tbh.


Darrsi seems clued up on the TPS units see what he thinks

darrsi

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Re: Stuttering engine below 4k (FZS600)
« Reply #9 on: 17 August 2017, 07:14:27 am »
The horrible thing about the TPS is that they don't tend to just peg out and stop working, they play silly buggers for a while until you just know something ain't right.
The obvious thing for starters is making sure the needle's sitting on the 5K position on the rev counter.
If it's not, then adjust it until it is but then keep doing quick checks on it every day if the bike doesn't quite feel like it should do.


If it keeps moving position, or stays on 10K or 0K, then it's on its way out.


You won't tend to notice it too much over 3000rpm, although it still won't be right, but under 3000rpm it will feel very jerky and you will need to use the clutch lever much more than normal to keep some kind of proper control over it.
It's possible you may suffer starting problems too, and also the tick over may not appear to be very stable either.

Unfortunately a dodgy TPS can also resemble a badly unbalanced set of carbs as well so keeping an eye on what the RPM needle is doing is important.
If that is showing as being stable on the 5K mark then it could be that the carbs just need syncing. If this is the case then you need to make sure your air filter isn't in a bad way either as any stuffed up airways can give false readings on balancing.


If you do think you may need another TPS unit, don't bother with a used/second hand one. These bikes are at least 14 years old now so, as i learned twice already, if you buy an electrical part that's 14+ years old with unknown mileage on it then it's just waiting to die as well so just buy a new replacement part and be done with it.


These will work on all models.


http://www.ebay.co.uk/itm/Yamaha-FZS-600-H-Fazer-2002-Tourmax-Throttle-Position-Sensor-/331848912138?hash=item4d43bc8d0a:g:~wYAAOSwQNRXK4wG
« Last Edit: 17 August 2017, 07:17:02 am by darrsi »
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celticdog

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Re: Stuttering engine below 4k (FZS600)
« Reply #10 on: 17 August 2017, 07:37:47 am »
The horrible thing about the TPS is that they don't tend to just peg out and stop working, they play silly buggers for a while until you just know something ain't right.
The obvious thing for starters is making sure the needle's sitting on the 5K position on the rev counter.
If it's not, then adjust it until it is but then keep doing quick checks on it every day if the bike doesn't quite feel like it should do.


If it keeps moving position, or stays on 10K or 0K, then it's on its way out.


You won't tend to notice it too much over 3000rpm, although it still won't be right, but under 3000rpm it will feel very jerky and you will need to use the clutch lever much more than normal to keep some kind of proper control over it.
It's possible you may suffer starting problems too, and also the tick over may not appear to be very stable either.

Unfortunately a dodgy TPS can also resemble a badly unbalanced set of carbs as well so keeping an eye on what the RPM needle is doing is important.
If that is showing as being stable on the 5K mark then it could be that the carbs just need syncing. If this is the case then you need to make sure your air filter isn't in a bad way either as any stuffed up airways can give false readings on balancing.


If you do think you may need another TPS unit, don't bother with a used/second hand one. These bikes are at least 14 years old now so, as i learned twice already, if you buy an electrical part that's 14+ years old with unknown mileage on it then it's just waiting to die as well so just buy a new replacement part and be done with it.


These will work on all models.


http://www.ebay.co.uk/itm/Yamaha-FZS-600-H-Fazer-2002-Tourmax-Throttle-Position-Sensor-/331848912138?hash=item4d43bc8d0a:g:~wYAAOSwQNRXK4wG



Hi darrsi, thanks for this.  :thumbup You're spot on about the tick over not being stable, it's not excessive yet but it does fluctuate a bit too much for my liking.

Unfortunately I'm going to have to live with it until the weekend when I can get a chance to look at it properly.

I'm in the middle of laying 90 x 60 x 5cm slabs in the back garden and I've got about 6 tonne of stuff to move about so god knows when I'll get it done.

Again spot on with the ebay link fella- it's a reasonable price, I was expecting a lot worse. If I do need to buy( I'm almost certain) I'll defo get a new unit.
« Last Edit: 17 August 2017, 07:38:27 am by celticdog »
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darrsi

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Re: Stuttering engine below 4k (FZS600)
« Reply #11 on: 17 August 2017, 01:12:05 pm »
The horrible thing about the TPS is that they don't tend to just peg out and stop working, they play silly buggers for a while until you just know something ain't right.
The obvious thing for starters is making sure the needle's sitting on the 5K position on the rev counter.
If it's not, then adjust it until it is but then keep doing quick checks on it every day if the bike doesn't quite feel like it should do.


If it keeps moving position, or stays on 10K or 0K, then it's on its way out.


You won't tend to notice it too much over 3000rpm, although it still won't be right, but under 3000rpm it will feel very jerky and you will need to use the clutch lever much more than normal to keep some kind of proper control over it.
It's possible you may suffer starting problems too, and also the tick over may not appear to be very stable either.

Unfortunately a dodgy TPS can also resemble a badly unbalanced set of carbs as well so keeping an eye on what the RPM needle is doing is important.
If that is showing as being stable on the 5K mark then it could be that the carbs just need syncing. If this is the case then you need to make sure your air filter isn't in a bad way either as any stuffed up airways can give false readings on balancing.


If you do think you may need another TPS unit, don't bother with a used/second hand one. These bikes are at least 14 years old now so, as i learned twice already, if you buy an electrical part that's 14+ years old with unknown mileage on it then it's just waiting to die as well so just buy a new replacement part and be done with it.


These will work on all models.


http://www.ebay.co.uk/itm/Yamaha-FZS-600-H-Fazer-2002-Tourmax-Throttle-Position-Sensor-/331848912138?hash=item4d43bc8d0a:g:~wYAAOSwQNRXK4wG



Hi darrsi, thanks for this.  :thumbup You're spot on about the tick over not being stable, it's not excessive yet but it does fluctuate a bit too much for my liking.

Unfortunately I'm going to have to live with it until the weekend when I can get a chance to look at it properly.

I'm in the middle of laying 90 x 60 x 5cm slabs in the back garden and I've got about 6 tonne of stuff to move about so god knows when I'll get it done.

Again spot on with the ebay link fella- it's a reasonable price, I was expecting a lot worse. If I do need to buy( I'm almost certain) I'll defo get a new unit.



Don't forget you'll need a T25 security torx tool to undo the screws if you need to adjust or remove the TPS.
They're only cheap and worth having in your tool kit.
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Re: Stuttering engine below 4k (FZS600)
« Reply #12 on: 17 August 2017, 05:03:36 pm »
ddddddddddddddddddddddddddddddddid yoyoyoyoyoyoyoyoyyoyoyoyoyoyoyoyoyoummmmmmmmmmmmmmmmmmmmannnnnnnnnagggggggggge ttttttttttttttoooooooooooo fffffffffffffffffffffffffffffffffix yourrrrrrrrrrrrrrrrrrrrrrrrrrrrrr sssssssssssssssssssssssssssttttttttttttttttttuuuuuuuuuuuuutttttering eeeeeeeeeeeeeeeeegine yyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyet

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Re: Stuttering engine below 4k (FZS600)
« Reply #13 on: 17 August 2017, 06:35:07 pm »
ddddddddddddddddddddddddddddddddid yoyoyoyoyoyoyoyoyyoyoyoyoyoyoyoyoyoummmmmmmmmmmmmmmmmmmmannnnnnnnnagggggggggge ttttttttttttttoooooooooooo fffffffffffffffffffffffffffffffffix yourrrrrrrrrrrrrrrrrrrrrrrrrrrrrr sssssssssssssssssssssssssssttttttttttttttttttuuuuuuuuuuuuutttttering eeeeeeeeeeeeeeeeegine yyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyet


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Re: Stuttering engine below 4k (FZS600)
« Reply #14 on: 23 August 2017, 05:28:27 pm »
Thanks for asking, but not yet. I'm taking it to the workshop tomorrow. Thanks again for all advice. Will let you know what was the cause, hopefully next week

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Re: Stuttering engine below 4k (FZS600)
« Reply #15 on: 23 August 2017, 05:41:22 pm »
Before I take it away; could it by caused by loose exup valve cables?
I've read somewhere that someone had simmilar problem with 2001 R1 and it turned out that exup valve was causing the stutter by staying open, not allowing enough back pressure at the low RPMS, because of loose cables.

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Re: Stuttering engine below 4k (FZS600)
« Reply #16 on: 23 August 2017, 06:23:02 pm »
although I think FZS600 doesn't have it, only 1000  :rolleyes

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Re: Stuttering engine below 4k (FZS600)
« Reply #17 on: 23 August 2017, 06:30:57 pm »
although I think FZS600 doesn't have it, only 1000  :rolleyes


No, doesn't apply to 600's.
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Re: Stuttering engine below 4k (FZS600)
« Reply #18 on: 06 September 2017, 11:46:30 pm »
I finally go the Fazer back from the workshop. The problem was with the carboratour and valves. There was too much fuel getting into it and that was a reason why it was losing power. Proper cleaning, including some liquid added to the fuel, solved the problem. Now it runs like brand like :) Thanks again for all advices.

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Re: Stuttering engine below 4k (FZS600)
« Reply #19 on: 07 September 2017, 07:09:19 am »
I finally go the Fazer back from the workshop. The problem was with the carboratour and valves. There was too much fuel getting into it and that was a reason why it was losing power. Proper cleaning, including some liquid added to the fuel, solved the problem. Now it runs like brand like :) Thanks again for all advices.


Hold on a minute, you need to explain this one a bit more?
Too much petrol can also mean not enough air, so could simply be a stuffed up air filter, or badly adjusted carb screws, or something sticking in the carbs.
And what liquid exactly was added to the petrol?
I've never ever known a mechanic to do this, they would much rather clean carbs manually for proper results and earn a few quid out of it in the process?
"Proper cleaning" would never involve additives, it would involve a 3-4hr labour charge.


Bit more info please?
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Re: Stuttering engine below 4k (FZS600)
« Reply #20 on: 07 September 2017, 08:34:36 am »
Too much fuel sounds like the float level was wrong.
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Re: Stuttering engine below 4k (FZS600)
« Reply #21 on: 07 September 2017, 08:50:57 am »

I finally go the Fazer back from the workshop. The problem was with the carboratour and valves. There was too much fuel getting into it and that was a reason why it was losing power. Proper cleaning, including some liquid added to the fuel, solved the problem. Now it runs like brand like :) Thanks again for all advices.

Strange ending to the story.
To much fuel means flooding and that points to stuck float bowl needles usually, or completely blocked air intake, although that would have been diagnosed as choked rather than flooding.

I would be interested to know what his workshop charged for the fix as it might indicate the amount of time was spent on it.
Fuel additives can be helpful in giving the the old carbatooters a freshen up and can help with descale or varnish removal, but if something like the needle valves or jets are completely blocked the answer is to blow them out with a powerful air line or replace them if they don't comply.
The bodies of carbs of yesteryear had fuel ways or capillaries running through the main cast alloy bodies if this still applies to the more modern carbs then theses need blowing out with the airline as well as it's no good having a nice clean jet with a mountain of crud behind it.

As Darrsi said a bit more info would be helpful to know and could help others diagnose their own problems.
« Last Edit: 07 September 2017, 08:52:07 am by tommyardin »

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Re: Stuttering engine below 4k (FZS600)
« Reply #22 on: 07 September 2017, 03:25:36 pm »
As you've probably noticed I'm not very good with technical details, but I will try to explain what I understood and remembered.
I took it to the workshop twice.
That's what's been done at the first visit:
- Air filters changed,
- Inlet manifolds Gaskets changed (I think),
- Spark plugs changed,
- Spark plugs cups changed.
Above things didn't solve the problem, so few weeks later I took it back and here what's been done:
- Carborauter cleaned using ultrasonic cleaner,
- Adjusting and syncing carborauter,
- Checked valve clearance,
- and that fluid for carborauter cleaning
After the second visit it runs awesome, the stuttering problem is gone and it feels like it has much more power than before the problem started, but I had to spend £300.
« Last Edit: 07 September 2017, 03:29:32 pm by feral kid »

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Re: Stuttering engine below 4k (FZS600)
« Reply #23 on: 07 September 2017, 06:12:25 pm »
Okay, so the carbs were cleaned properly, hence the bill.
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Re: Stuttering engine below 4k (FZS600)
« Reply #24 on: 08 September 2017, 08:09:26 am »
Expensive but sucsessful, jobs done  :thumbup :thumbup :thumbup