ODD JUDDER ON SLOW JUNCTIONS ETC

[TOM VR46]

This is something that came with the bike and i have sort of got used too,, but  always been thinking about.   And now something in [size=0px]Dman2019[/size][/color]'s clutch change topic has got me thinking again.
Symptoms,  a judder felt when taking slow junctions. One i take quite often is , off a main road , turning right ,into a small rise and sort of back on yourself again.
Solution , a touch of rear brake and no judder ..
It can happen on any slow junction and i have just learned to live with touch the rear brake gently and no judder. Nothing has ever changed it , for example new cush drive rubbers, new chain and sprockets, new rear wheel bearings, new clutch cable. Rear swing arm has no play but havent done that yet. But,,, back to [/size][size=0px]Dman2019[/size]'s topic. It mentions a JUDDER SPRING [/size][size=78%],,, mmm,,,, judder[/size] [/size][size=78%] ,,, well thats what im feeling,,, so any ideas.[/size]
This isnt urgent, as ive got used to it. But if i have spare time or even just serviceing the old bike , do you think it would be worth a wee look.
Any suggestions welcome.

[darrsi]

"...a judder felt when taking slow junctions..."


I'm not totally understanding what that actually means?


I had a "judder" feeling, as i called it, on my bike many years ago, but that was to describe a feeling when braking.
The juddering i was getting felt like l was braking on cobblestones with a very unsettling feeling at the front end of the bike.
After changing all sorts of things the only thing left to replace was the front brake lines, and the only reason i had previously left them alone was because they were aftermarket braided lines, but it turned out that the previous owner had somehow managed to damage one enough to send me crazy.


I'm guessing this is not the same issue as yours though?


Are you accelerating or decelerating at these slow junctions? Where is the juddering coming from, the front, the back, the middle, the whole bike?
Any noises associated with this feeling?


Need a bit more concise info please.

[Fazerider]

My guess is that what you’re feeling is the chain. Obviously the top run goes from being taut to slack and then taut again as you roll off and then accelerate. I normally apply a gentle drag with the back brake to make slow corners smoother.
Check the chain adjustment is correct.
Having the idle speed set too low (or unbalanced carbs) also makes throttle response jerky.

[TOM VR46]

Whats it like ?  Its like taking a 2nd gear junction in 3rd, and comes from the middle to rear of the bike. And starts just at the point of accelerating. Once straightened up all is fine.  And to cure it, as Fazerider does and i do , is gentle drag on rear brake .
But ive always thought it was just a little to much judder [size=78%], without the rear brake drag,,, and so its always been on my mind is there something else that would smooth it out a bit more. [/size]
[/size][size=78%]Everything thats been done to the bike has made no difference. Chain is all ok. Carbs were balance a year ago , no difference. Throttle is quite responsive and again new cables last year,, no difference. [/size]
[/size][size=78%]But,,[/size] ,, this wee judder spring in the clutch.  Would that make any difference?  I dont know how much work this spring does and its in an engine that is coming up for 70,000 miles. So , it was just a wee thought.
Ive always used rear brake at slow riding, just wondering if i could make things smoother without rear brake.

[fazersharp]

Wrong gear for the off throttle speed, that chain catching up with itself thing ?

[BBROWN1664]

When under acceleration, constant speed or when braking?

When under acceleration, it sounds like you are in too high a gear. Change down. Keep the revs about 4k.
If constant speed, probably the chain slapping around. Try a lower gear.
When braking, could be tyre shape or worn pads but these normally show themselves more at higher speeds

[TOM VR46]

Hard to explain.  . Not wrong gear choice. Like Fazerider i use rear brake to smooth out the likes of slow 2nd gear corners/junctions. 1st too slow, 3rd to high. On say a flat 2nd gear junction, just at the point of acceleration if i dont use rear brake you can feel a slight judder. Not before entering the junction, its the point that you would be round , applying throttle to change up again. But a little gentle rear brake when turning in and no judder.
But the sort of junction i first mentioned. Again a 2nd gear junction if no traffic. Turn right into junction, slight up and turning back on yourself.
 Now, 1st too slow, 3rd too high for up and round. So 2nd. Now , as i go up and round , if i was to not use rear brake youd feel the bike judder until round and straight.  But , gentle rear brake and all is fine. A bit like using rear to pull you round.


But on a flat junction where youd think , just glide round in 2nd and away,  theres that wee judder. 3d too high, 1st too slow.
As its been like this since i got the bike ive always thought about it. And when any work has been done wondered if it would smooth it out a bit, but nothing has ever changed.
Then up pops this wee judder spring in the clutch. Where and when does it stop judder?  Would over the miles become stretched or worn that would make the bike judder at any point. If at the point your putting load onto the bike to accelerate from slow speed would or does it take any pressure form the clutch to perform. Just a wee thought that made me think a bit. What juddering does it help and when?

[TOM VR46]

Wee confession time .  After a lot of reading and looking for a JUDDER spring as mentioned in Dman2019 post,, this is the Tension spring on the left of the engine. Oops . I thought there was another spring somewhere in or around the clutch basket,,,nope.
But as usual i have been looking and reading about clutch related problems from way back on the Fazer and there have been some weired problems, with some good ideas and results of what is causing the problem,,,,and alot of head scratching .


But for me i think its just one of those things that make my Fazer a wee bit different but dosent affect her running. One possible idea for me is up 1 tooth on engine sprocket. Going from 15 to 16 seems in afew cases seems to smooth ride out. But for now ill stick with 15.
There was alot of noise related problems but some did not affect the bike running.
So for me ill wait and see how she goes. Maybe in future if clutch needs changing then ill see what happens but for now dosent affect performance so ill ride on.
Well suns out , so time for wee spin. 

[darrsi]

You say you had a carb balance, but do you have any idea of what condition the air filter might have been in? Was it new, recent, old? Looking at it doesn't count!


If you had a carb balance with a filter that was on its way out then it's possible it could have made things worse.


Just a thought. I have a K&N filter on mine and will always give it a clean before I do a balance.
K&N let more air in though so they're not as critical, but a clogged paper filter can cause what to me sounds like a stutter.


A TPS that is breaking down can also cause this effect, as can a breaking down spark plug too.
Two more things that also need to be good before a carb balance can be done with best results.

[TOM VR46]

Thanks Darrsi.  Yep air filter and plugs and caps were done approx same month as carb balance. The reason for carb balance was poor running. And again it was one thing at a time,, till i found perished carb rubbers, in fact one was split. So after having everything of to fit new rubbers and also at that time i changed the throttle cable as the carb end was dry and a tad rusty.
And yep i use K&N filters, air and oil.


Because i use rear brake for tight turns i was never too bothered about the judder if i didnt use the brake as i thought it was cush drive related. But nope. And as i said theres no play any where else that i can find. Nothing was found when shes mot'd so onwards and forwards.


One thing that may have made a slight difference was when i changed spark plugs. There was nothing wrong with old ones i just decided to change to iridium ones,, just being nosey as i have read alot about them on here. I would say i found these smoother when bobbing in traffic. They seem more responsive when on/off throttle quick. Maybe just me.


After alot of reading i would say maybe the clutch has something to do with it. But theres no need for me to be in there at the moment.

[darrsi]

Iridium plugs all the way for me, i do notice a difference.


Years ago I had a different set of carbs put on my bike, I can't remember why but I think it was an easier and cheaper option than repairing the old ones.
After the bike was good to go I found that on hard acceleration the bike would stutter and bog down a bit.
Everyone was puzzled as to why this was happening until eventually another mechanic i use occasionally found that #2 carb rubber had folded in on itself on refitting, and was letting a tiny amount of air in. But due to where it is you couldn't see it at all. Thought it might be worth mentioning.

[TOM VR46]

Yep. I had a problem when refitting carbs too.  I was having trouble holding carbs in place while tightening up clamps. Id find that when i was tightening one side the other would start to slip back out.  I was trying not too over tighten the clamps  as i didnt want it to them to cut into the carb rubbers as there not cheep.
So i managed to hold the carbs in place with some cable ties and then tighten the clamps down slowly. Once i got everything in place , carbs into inlet rubbers, and air filter connected up i used some electrical spray to do the final tightening up.  With the bike running and the odd squirt of spray you could hear when the clamp was tight and making a good seal without over tightening clamps.