Shudder when decel below 3,000 RPM

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FZ648

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New to the forum and the site today, I hope someone can help a newbie.
Just bought a 2006 FZ6. (only 4700 Km on the ODO) Minty. It's my first streetbike, after riding off-road with a YZ.

I was able to take it out the other day for the first time and bike was fantastic. Very smooth and predictable. I did notice however, that when decelerating, (engine braking), when the RPM got below approx 3000, the bike would shudder. No brakes being applied. It almost felt as though the compression may be doing this, or the clutch may be involved somehow.
When I pulled the clutch in, it went away instantly.

Does this sound like a typical FZ6 attribute?

Thanks in advance.
 
well if i remember than 2k is the lowest number on the revs. so at 3k you are only just over tick over. maybe the bike was just begining to stall? like bouncing? thats all i can think of with that descripton is the bike stardard?

Hope it is only somehting minor if it is something
 
:welcome:to the forum!

The FZ6 is a revy engine. If it shudders with the throttle closed I would almost expect there could be some fuel still being introduced. My first conclusion might be an injector nozzle still allowing small amounts of fuel or the TPS (Throttle Position Sensor) telling the ECU there is intermittent throttle opening.

I would run a few tanks of fuel with some Sea Foam (or equivalent) to possible clean a dirty injector/s.

The TPS can be tested from placing your readout in diagnostic mode and seeing that it falls with in specs.
 
I wouldnt worry about it unless its a SERIOUS shudder, even in 1st goin like 10mph with the clutch out itll bounce a bit, even cars do it when they are kinda close to stalling out.....
 
Welcome!!!

What gear were you in? What you described sounds like is was about to stall out, simple solution if that was the case, go faster lol
 
Thanks for the quick replies.
It happens in 3rd, 2nd or 1st gears.
I know what a motor feels like, when it is getting close to stalling, but this just seems like too high of an RPM for that to happen.
( I would certainly expect it to be jerky below 1500 RPM or there-abouts )
The Sea Foam or fuel injector cleaner sounds like a good idea. I also did not know there were diagnostics on-board. (have not read the manual yet)

Thanks
 
10hp and even less torque at that low a rpm, its probably not even close to the powerband.... some clutch slipping is still needed even in 1st if you want it to be smooth.
we have 14,000 rpms to play with, why bother with the bottom 3,000? :BLAA:
 
My first thought was "why are you closed throttle with clutch engaged at 3k rpms?" There's your problem right there. Don't do that.

Next...
 
Congrates on the new bike and welcome to the forum!

Just an FYI, while riding home tonight on my 07, I let the bike in 6th gear slow fully down to 1200 RPM (no braking) with NO shudder before pulling in the clutch. (I do have the idle set at 1000 RPM's). I did the same in 1st,
2nd and 3rd, all the way down to 1,000 RPM's, again, No shudder...

BTW, the bike idleing IN GEAR (stock gearing, I'm about 200 lbs) would pull at 1000 RPMS, in 1st, 2nd and 3rd gears with no additional throttle, no shudder/bucking etc...(flat surface)

Something isn't right...

I normally downshift, with the clutch, one gear at a time as the bike slows (approx 1 gear per 10-15 MPH on de-cel)..
 
Thanks again everyone. I think a couple of people did not notice that I am decelerating when I have this problem, therefore the Hp and torque are not a factor.
The bike will pull just fine from these lower RPM's, I don't have any problems when ON the throttle, it is just when I am OFF the throttle approaching the lower RPM's.
TownsendsFJR1300 thanks for doing the tests for me. Your results sound like the way it should be. My riding was similar, 180lbs, flat surface etc. I am about 3500 ft above sea level, but the FI should take care of the mixture and compensate.
I have read that the fuel injection mapping was re-done for 2007, so I was interested to know if that had any bearing on my problem. (mine is 06)

If I can't figure it out in the next little while, I may run it into the dealer to let a mech take it for a spin. It is still March here in Canada, so riding right now is a little early anyway.:D
 
i also tested mine last night after reading this thred yesterday and i noticed that mine did start to judder when i had no throttle on at all and let the revs fall near the 2-3k mark all the way down to stall.

I have the 2005 model so should be same shape as yours.

Mine was barly noticable tho and nothing i would normally pay attention to. so try running some cleanren through it and see what happens and if the problem continues get the dealer to check it out
 
Your welcome.

I did forget to state, I am at sea level and use Seafoam/techtron and K100
( K100 Fuel Treatment : Fuel Additive, Fuel Saver )- K100-MG fairly often so I believe my fuel system is pretty clean.

The iridium spark plugs seem to work as well. It idles rock solid at 1000 RPM's, Yamaha wants the idle set around 1300 RPM.

Something you may look at is checking the throttle sync. If you have a good amount of vibration thru the bars/seat, its a good indication it needs syncing, especially if it hasn't been done in awhile (very easy with a manometer).
 
I also think some thing may be a miss. I ride my bike around the garden with the kids on the back at just over tick over speeds. No issues with closing throttle or accelerating.
Nelly
 
My bike does the same thing, but I only really noticed it after I changed my sprockets.

It's not that big of a deal because if you're down to 3k you should pull in the clutch, brake and shift into first so you're ready to take off.
This bike isn't really meant to cruise off-throttle at low speeds.
 
My bike used to do the same thing. I would let off the throttle in 5th or 6th, as I slowed down and started to downshift I would start to get a shutter all the way till I pulled the clutch in. I recently installed a Two Bro's juice box and the shutter went away and haven't felt it yet. My bike is a 2005 with almost 14,000 miles and Leo Vince cans.


Sent from my iPad using Tapatalk
 
TownsendsFJR1300 said:
Something you may look at is checking the throttle sync. If you have a good amount of vibration thru the bars/seat, its a good indication it needs syncing, especially if it hasn't been done in awhile (very easy with a manometer).
Click to expand...

That would have been my first thought!

Cheers,
Rick
 
Well, I did the diagnostic on the TPS and it goes from 16 - 101. Nice and smooth and repeatable. Tried it many times. Same figures. 16 - 101.
I know I could pull the clutch in at 3000, but it just does not seem right, to have to do this. I will poke around and see what else it could be and keep you posted. This forum has given me lots of things to chase down.
 
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