Slow return to idle after closing the throttle

[unfazed]

For those chasing a slow return to Idle after closing the throttle on the FazersI had been chasing this slow return to idle on my 2003 Fazer 600 for a while and bike was a bit lazy on the throttle, response not as positive as it used to be. 
Everything checked out, nothing was wrong, I was totally baffled by it.
I took the carbs off to go through everything. Checked each of the diaphragms twice for holes and splits. Checked Inlet manifolds, and all vacuum caps, all were fine.
Evertyhing was absolutely as it should be
When putting the carbs back I was looking at how the air equalises at the top of the diaphragms. Removed the little gauze filter housing which allows the air to the vents in and out as slide rises and fals. Looked at it and it looked fine. Stuck a small LED light into the the back and could only see a few specks of light through it. Decided to try cleaning it and used Carb cleaner and an old beard trimmer brush as I could not remove the gauze.
See pictures of location of filter, what it looks like off the bike, plus the before cleaning and after cleaning. Bike is back running like new since and throttle response is back to normal. My theory was that since it couldn't breath in and out through the vents it was using the small holes on the base of the slide near the needles to equalise the air above the diaphragm and was slowing the rate of ascent and decent of the slide. It happened so gradually it wasn't notice. I have since checked my sons 600 and my 1000 and both were partially blocked. Cleaning these also improved the throttle response. My 600 has 955000 miles on it and both my sons 600 and my 1000 have about half that.

[Trebus]

Thanks Unfazed, excellent bit of knowledge.

[beuleux]

Useful info if anyone else comes across this problem, not an obvious thing. Thanks for sharing 👍

[fazerscotty]

Nicely found - I'm wondering if these could be cleaned in an ultrasonic cleaner.

[Dave48]

Don't see why they shouldn't be safe in an ultrasonic cleaner. Maybe use a mild detergent solution. I am more than happy with mine and it cleans some very delicate components no problem

[robbo]

Excellent fault finding unfazed, thanks for sharing

[unfazed]

I must put it up on the Facebook group as some members there are not on this forum.

[FazThou]

Another great piece of advice
Well done unfazed

[Kenyun]

 Nine hundred and fifty five thousand miles!!!!...no wonder it was feeling a bit lazy, poor old thing.

[unfazed]

Nine hundred and fifty five thousand miles!!!!...no wonder it was feeling a bit lazy, poor old thing.

That's what I thought also

[b1k3rdude]

Added link to FAQ.

[unfazed]

For those chasing a slow return to Idle after closing the throttle on the FazersI had been chasing this slow return to idle on my 2003 Fazer 600 for a while and bike was a bit lazy on the throttle, response not as positive as it used to be. 
Everything checked out, nothing was wrong, I was totally baffled by it.
I took the carbs off to go through everything. Checked each of the diaphragms twice for holes and splits. Checked Inlet manifolds, and all vacuum caps, all were fine.
Evertyhing was absolutely as it should be
When putting the carbs back I was looking at how the air equalises at the top of the diaphragms. Removed the little gauze filter housing which allows the air to the vents in and out as slide rises and fals. Looked at it and it looked fine. Stuck a small LED light into the the back and could only see a few specks of light through it. Decided to try cleaning it and used Carb cleaner and an old beard trimmer brush as I could not remove the gauze.
See pictures of location of filter, what it looks like off the bike, plus the before cleaning and after cleaning. Bike is back running like new since and throttle response is back to normal. My theory was that since it couldn't breath in and out through the vents it was using the small holes on the base of the slide near the needles to equalise the air above the diaphragm and was slowing the rate of ascent and decent of the slide. It happened so gradually it wasn't notice. I have since checked my sons 600 and my 1000 and both were partially blocked. Cleaning these also improved the throttle response. My 600 has 955000 miles on it and both my sons 600 and my 1000 have about half that.

Just to Add to this There are two slightly smaller similar filters on the 1000 one for carbs1 & 2  and one for carbs 3 & 4
I did not have the 1000 out until last Sunday, but  knew from the throttle response  after starting it when I had refitted the filters after cleaning them if was much impoived. What a difference it made to riding the bike, so much so even my wife noticed the difference and asked what I did to the bike since it felt like it was mad to go. It took me a while to get used to the throttle response. The full effect of Ivan's kit modification were finally unleashed