Author Topic: Irregular Knocking vibe from front (Read 3343 times)

Frosties · « **on:** 28 July 2015, 07:48:37 am »

Hiya fellas,
Hope you can help me out again.

Noticed over the last couple of days that on load and above 5-6k Rpm and 40mph there seems to be a slight irregular knock which feels like it's coming from the front of the engine - nothing rolling off or at idle or even when clutch dipped at any speed.

Now I know the cam chain has been noisy since I bought it some 16k miles ago and was wondering if this could be the culprit.

Any ideas welcome. Cheers

darrsi · « **Reply #1 on:** 28 July 2015, 10:17:12 am »

Cam chain noise is more like a sewing machine soft rattle rather than a knocking sound.
If it is that you may just be in between clicks of the tensioner. Took mine about 7 months last time before the noise just disappeared as the bike was ticking over while I was putting my lid on.
The silence was deafening, because I'd got used to the rattle.

celticdog · « **Reply #2 on:** 28 July 2015, 10:47:11 am »

Slight knock . . . is it more of a rumble, squawk or a tapping noise? A rumble could be the bottom end bearings at the crankshaft.
If it's a squawk sound is probably clutch wear and a ticking sound from the top of the engine could be worn tappets/shims.
She's getting on a bit, any bike after 15 yrs is probably going to have the odd knock, it's one to ponder, as long as it doesn't get
any worse

Frosties · « **Reply #3 on:** 28 July 2015, 11:30:44 am »

It's definitely not the cam chain noise, not a clutch sound (too far forward for that), and not tappets.
If you imagine a rumbling bearing, then take one rumble and make it irregular (about as regular as a tennis ball in a washing machine) then that's about the best I can describe it. Only on load and doesn't matter if it's on a constant throttle opening or increasing opening. I know this is going to be a bugger to pin down. Will try and gleem more info on my 50 mile route home tonight - different gears, revs, speed etc

unfazed · « **Reply #4 on:** 28 July 2015, 02:22:38 pm »

Put it on the centre stand, put it in neutral.

1. Start it, let it tick over is the noise there?

2. Rev it to 3000 revs is the noise there.

Do 1 and 2 above again, but this time with the clutch pulled in. Is the noise there?

Frosties · « **Reply #5 on:** 28 July 2015, 03:00:23 pm »

Quote from: unfazed on 28 July 2015, 02:22:38 pm

Put it on the centre stand, put it in neutral. Done

1. Start it, let it tick over is the noise there? Nope.

2. Rev it to 3000 revs is the noise there. Nope

Do 1 and 2 above again, but this time with the clutch pulled in. Is the noise there? Nope

unfazed · « **Reply #6 on:** 28 July 2015, 06:10:21 pm »

Ok, that is good.

Again on the centre stand in neutral. engine off

Can you lift the chain more than 5mm off the rear sprocket?

Spin the wheel as quickly as possible, any noise?

Frosties · « **Reply #7 on:** 28 July 2015, 07:23:14 pm »

Can only lift chain about 2mm off sprocket.

Checked chain - no tight spots. Gets lubed every 200 miles (2 days)

Noticed tonight on way home that I can feel the vibe through left foot peg - same irregular frequency as before.

unfazed · « **Reply #8 on:** 28 July 2015, 07:29:30 pm »

Again with the bike on the centre stand and in neutral.

Push the chain up where the swinging arm rubber protector is.

Does the chain touch the rubber swinging arm protector when pushed up?

Frosties · « **Reply #9 on:** 28 July 2015, 07:32:08 pm »

Quote from: unfazed on 28 July 2015, 07:29:30 pm

Again with the bike on the centre stand and in neutral.

Push the chain up where the swinging arm rubber protector is.

Does the chain touch the rubber swinging arm protector when pushed up?

Christ you're quick fella - hang on, I'll pop out

Frosties · « **Reply #10 on:** 28 July 2015, 07:35:14 pm »

Quote from: Frosties on 28 July 2015, 07:32:08 pm

Quote from: unfazed on 28 July 2015, 07:29:30 pm
Again with the bike on the centre stand and in neutral.

Push the chain up where the swinging arm rubber protector is.

Does the chain touch the rubber swinging arm protector when pushed up?

Christ you're quick fella - hang on, I'll pop out

Nope - chain won't touch swing arm protector.

unfazed · « **Reply #11 on:** 28 July 2015, 07:51:31 pm »

Tight Chain, most likely your problem.

Adjust the chain until it just touches the rubber and make sure the marks on the swinging arm line up.

Frosties · « **Reply #12 on:** 28 July 2015, 07:57:14 pm »

Quote from: unfazed on 28 July 2015, 07:51:31 pm

Tight Chain, most likely your problem.

Adjust the chain until it just touches the rubber and make sure the marks on the swinging arm line up.

Ohh no, what a plum

Thanks for your time and help fella - much appreciated

Frosties · « **Reply #13 on:** 28 July 2015, 08:56:12 pm »

Quote from: unfazed on 28 July 2015, 07:51:31 pm

Tight Chain, most likely your problem.

Adjust the chain until it just touches the rubber and make sure the marks on the swinging arm line up.

Ok, adjusted chain to give 30mm slack (had 20mm before). Been out for quick spin and still got the irregular knocking. Tried smooth and rough road surfaces, no change. No hesitancy on pick up, nice n smooth.

unfazed · « **Reply #14 on:** 28 July 2015, 09:05:55 pm »

Does it happen all the time or under braking and acceleration?

Check you head stock bearings.

Back on the centre stand again grab the two lower fork legs pull forward and push backwards.

If you can, get someone to push down the rear of the bike while doing the check.

Any sound?

Frosties · « **Reply #15 on:** 28 July 2015, 09:12:34 pm »

Only happens on an open throttle (part or full) - either accelerating or maintaining speeds above 40ish mph. Nothing on closed throttle, decelerating, braking or idle.

Cheers fella - going to have to check the bearings tomorrow at work cos the mrs cant be arsed to help.

Let you know tomorrow, cheers

mr wayneker · « **Reply #16 on:** 28 July 2015, 09:40:06 pm »

ive just had the same and it was the rear sprocket carrier bearing,,,,when off the bike the sprocket was really lose
like there was no grease in there...when you span the sprocket with your fingers in the bearings you could just feel the
irregularity in the bearing....only just but enough to cause a nock and a squeal...nock up to 60mph
and a squeal 5-30mph,,,,,,,started with a slight vibe first 200miles into my journey...had taken her up to 120mph
that day to......

a friend said its been on there probably 15years never changed and got to hot and gave up the ghost

unfazed · « **Reply #17 on:** 28 July 2015, 10:06:13 pm »

Best to check out one thing at the time, if the head stock bearings are ok then on to the wheel bearings.

Frosties · « **Reply #18 on:** 29 July 2015, 07:37:56 am »

Ok, with the help of a GS rider holding the back down, checked the head stock bearings this morning and no issue there. No play and as smooth as you like.
Now I know I failed on 2 counts a) Letting a GS rider touch my bike b) talking to a BMW owner - buuut he was the next guy to turn up at the bike bay. Nearly fell over when he spoke back to me and said yes he'd help

We going wheel bearings now?

unfazed · « **Reply #19 on:** 29 July 2015, 11:32:47 pm »

Quote from: Frosties on 29 July 2015, 07:37:56 am

Ok, with the help of a GS rider holding the back down, checked the head stock bearings this morning and no issue there. No play and as smooth as you like.
Now I know I failed on 2 counts a) Letting a GS rider touch my bike b) talking to a BMW owner - buuut he was the next guy to turn up at the bike bay. Nearly fell over when he spoke back to me and said yes he'd help

We going wheel bearings now?

Thats it! No more help from here

Frosties · « **Reply #20 on:** 30 July 2015, 07:41:01 am »

I know , I know........still feel totally shamed even now

. I have steam cleaned where he touched the bike and now require a new seat (disintegrated after 20 mins of high pressure steam - poor build quality I think) but consider it s a very small price to pay for removing all evidence relating to BMW contact.
Still don't know why I didn't wait for a scooter rider to turn up....2 mins later one of those tricycles turned up

unfazed · « **Reply #21 on:** 30 July 2015, 08:54:07 am »

Ok, your forgiven this time since you went to so much effort to erase all possible contamination/infection

Keep an eye on the rad, assimilation is slow but it the rad deteriorates first when the fazer tries to transform to being air cooled. Rider can be infected also with sudden urges to go to BMW garages to look at boxer twins

Do not leave a scooter rider near it or you will have sudden urges to put 40 mirrors on the front and spend years try to convert the fazer to twist and go,

there is no cure for that infection

Best way to check wheel bearing is with the calipers removed or at least have the pads pushed back into the calipers.

The pads close to the disk can mask bearing play.
Again on the centre stand, front off the ground. (you could use the GS rider again for this, but make sure he wears gloves, but under no condition allow him touch it if he is wearing BMW gloves)

.

Calipers off or pads pushed back
Spin the front wheel, it should be quite, no strange noises.
Hold the wheel top and bottom and try and rock it. There should not be any play or movement
You may as well do the back as well at the same time.

Frosties · « **Reply #22 on:** 30 July 2015, 09:25:38 pm »

Quote from: unfazed on 30 July 2015, 08:54:07 am

Ok, your forgiven this time since you went to so much effort to erase all possible contamination/infection
Keep an eye on the rad, assimilation is slow but it the rad deteriorates first when the fazer tries to transform to being air cooled. Rider can be infected also with sudden urges to go to BMW garages to look at boxer twins Assimilation started - bike dumped its coolant and ive stopped nodding to other riders
Do not leave a scooter rider near it or you will have sudden urges to put 40 mirrors on the front and spend years try to convert the fazer to twist and go, there is no cure for that infection The feccin wheels have shrunk

Best way to check wheel bearing is with the calipers removed or at least have the pads pushed back into the calipers.

The pads close to the disk can mask bearing play.
Again on the centre stand, front off the ground. (you could use the GS rider again for this, but make sure he wears gloves, but under no condition allow him touch it if he is wearing BMW gloves) .

Calipers off or pads pushed back
Spin the front wheel, it should be quite, no strange noises.
Hold the wheel top and bottom and try and rock it. There should not be any play or movement
You may as well do the back as well at the same time.

Ok, calipers removed and wheel spun (bag of sand on pillion seat) - nice n smooth, no hint of rumble. Top/bottom has no rocking. Rear the same.

Could a lost wheel weight cause this or uneven tyre wear. Metzeler Z6's fitted - front has 13,000 on it and just starting to square off with the extra angle from road camber just starting. Rear has done about 10,0000 and just starting to square off. Do 100 mile a day, half m/way at 90-100mph plus hustling round London and I don't hang about.

unfazed · « **Reply #23 on:** 30 July 2015, 10:00:25 pm »

13000 miles on a front tyre, 10000 on the back tyre,

foc, never got more then 8000 miles from a front or 6000 from a rear.

Everything seems to check out and loss of a weight would cause vibration and uneven wear especially on the centre of the tyre.

Since you have the box eye I wonder if the shroud over the left side bulb has fallen off. Look at the left lens and see if the shroud is still over the bulb. If it is take out the bulb and check with your fingers if there is any movement on the shroud.
Don't get to carried away there is no hair there and the edges are hard

Frosties · « **Reply #24 on:** 30 July 2015, 10:25:51 pm »

Quote from: unfazed on 30 July 2015, 10:00:25 pm

13000 miles on a front tyre, 10000 on the back tyre, foc, never got more then 8000 miles from a front or 6000 from a rear.

Everything seems to check out and loss of a weight would cause vibration and uneven wear especially on the centre of the tyre.

Since you have the box eye I wonder if the shroud over the left side bulb has fallen off. Look at the left lens and see if the shroud is still over the bulb. If it is take out the bulb and check with your fingers if there is any movement on the shroud.
Don't get to carried away there is no hair there and the edges are hard

Got 17,000 out of a set of Anakee 3's fitted to the Tiger and honestly I don't hang about - reckon it's the m/way mileage that eases the wear.

Bulb shroud is definitely in place, will check it out tomorrow.

Cheers fella