Got my zx12r running last week and took it out for a shakedown. All is well except I'm experiencing a heavy vibration in the drivetrain when pulling away in first gear.

This is a new noise since fitting the new engine.
I've tried 2 different clutches and different sets of springs. And it's still there.

Things in the drivetrain that have changed since engine swaps-

Prop has been shortened (I did force the prop in place putting pressure on the diff input flange before having it shortened 25mm )
Prop has increased angle from the centre bearing

No changes to the diff (Sierra LSD) itself but the noise sounds likes it's coming from there


The clutch works fine once rolling, no noises etc, it's only whilest pulling away from a stand still

Any help on this would be appropriated as I'm struggling.

My thoughts now are a diff issue (is it maybe just locking up with the increased torque?) or something like the clutch basket.

Sounds like clutch/flywheel alignment issue or a warped or uneven material deposited on the fly wheel.
I had a similar issue after my last clutch was changed on clio, when i replaced the box a few months back, i gave fly wheel a light rub down and carfully relocated the clutch and it went away.

[Edited on 28-12-16 by loggyboy]

quote:

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Originally posted by loggyboy
Sounds like clutch/flywheel alignment issue or a warped or uneven material deposited on the fly wheel.
I had a similar issue after my last clutch was changed on clio, when i replaced the box a few months back, i gave fly wheel a light rub down and carfully relocated the clutch and it went away.

[Edited on 28-12-16 by loggyboy]

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Sounds like it maybe a clutch issue then

Prop not balanced or worn centre bearing that is now more apparent due to changing positions/modifying length?

have you replaced the clutches complete, including the basket? If not I wonder if the clutch centre is failing.
I doubt the prop it the issue at such low speed unless you've really put a strong angle on it

Not the clutch basket, just the fibres and steels. It was exactly the same with both clutches., One oem and one was updated.

When the prop was shortened it wasn't re-balanced but I'm thinking the same...such low speed shouldn't be noticeable if it's out of balance but I'm certainly no expert here.

Deffo a clutch issue,propshaft would be at higher speeds,and diff would be all the time not just as you are taking up drive.

I had it with the original clutch in my R1 engine where I had not noticed the diaphragm Spring was meant to be fitted in a certain position.

Have you followed the tightening procedure up correctly on the clutch springs?

Is the clutch basket notched where the steels and plates move out, this would lead to poor take up.

quote:

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Originally posted by mark chandler
Is the clutch basket notched where the steels and plates move out, this would lead to poor take up.

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I've not checked the basket to be fair, so remove the clutch and look for imperfections on the basket?

Yeah where the square side pegs on the clutch plates sit in the slots on the basket.

You might find small dips/worn parts,the plates should be able to slide out smoothly but if there are indents they can catch on these and not release smoothly

Also check all your engine mountings are sound and tight, could be the torque reaction moving the engine on its mounts as you take up drive.

Ok so...took the car out for another drive yesterday.

Noticed a few things

My prop is definitely needing balanced as I'm getting a vibration around 60/70 mph.
The heavy vibration at take off is worse once the engine is hot
If I'm super careful with clutch control- not easy in a Bec i.e nice and slow with lower revs whilst pulling off, then it's much better
Diff has plenty of clean oil.

Other stuff if found out...
The ZX12r A1 engine can suffer from poor clutch lubrication, drilling the basket can help this.
It also has an 'anti judder' spring and spacer between the first friction plate and steel, this is in place and fitted correctly but I'm going to replace it just in case


It's a strange one, but I'm trying not to just throw parts at it aimlessly

Il will get the prop balanced and do the judder spring for starters.

It's Deffo a clutch issue then if engine heat alters it.

Are the plates/steels new?

Have you got enough engine oil in it?

Yup, sight glass is full when cold so if anything it's maybe a little over filled. The engine sits ever so slightly nose down in the chassis, I've had the sump shortened, baffle plate Fitted
I'm suspicious of this clutch lubricating issue that the A1 could suffer from.
Have a wee look at this link - http://kawasakiworld.com/racing/37186-not-enough-oil-clutch-pack-how-fix.html#/topics/37186?page=1&_k=4pepjn

Although I don't want to send myself on a wild goose chase if it's something simple (oil level or judder spring)

The oem clutch which is in it now isn't new but the other clutch I tried was new, so I've tried 2 full clutched (steels and friction) and the issue is no different

The issues wasn't present with my old engine and the bike ran fine before I broke it, although I think the extra weight of the car is probable exaggerating the problem since it's a take-off/loading issue

[Edited on 31/12/16 by flanders]

How much have you had taken off the sump?

They said approx 30mm, and increased lost capacity sidewards

ordered new clutch pull rod, pull lever, needle bearing, judder spring and washers.

when im back in there ill inspect the grooves in the basket and probably do the oil supply mod in the link above, also getting the prob inspected and re-balanced fingers crossed