Vibration

[chunky]

My ski has a strong feeling of vibration.
It seems to come from every where, i can feel it through my bars and under my feet!
I took out the pump and drive shaft and i could still feel it through the bars.
I took of the fly wheel cover and set a plunger gauge on the fly wheel and turned it over by hand, there was only 0.14mm of movement on the gauge.
I have no idea what is causing this.
Any suggestions??

 

[SuperJETT]

The engine probably needs to be aligned better or you have a bad engine mount.

Pull the engine, take the rubber dampener out, align it using a straight edge across the couplers and a light behind so you can see gaps, take the shims out, put the dampener back in, then reinstall the shims and tighten it down.

 

[chunky]

will try the engine alignment then.
engine mounts brand new, changed them when the wee ends and crank seals got done. this is when the vibs started!!

 

[kx454]

maybe a bent crank?

 

['Crockett]

Check your starter bendix . . . . may be sticking in the engaged position and staying there while the engine is running.

They rotate on bronze bushings and are not designed to turn at rpms above that of cranking speeds. Inspect the busings in the case and the cover to be sure they are not all ate out if you have run it for an extended time.

I've seen this on several SuperJets . . . . .

 

[chunky]

thanks guys
have to sign out now, getting late here.
:sleepy:
all posibilities welcome.

 

[Mike Serlin]

A quick way to semi align the motor is to make sure the rubber piece inbetween the coupler is "floating" by trying to see if it wiggles with your hand. If not you need to shim the motor, usually up, until you can wiggle it.

 

[sjetrider]

If you have new aftermarket motor mounts they will vibrate until they break in too. Usually 5 to 10 rides.

 

[SuperJETT]

And if you have Wammer mounts along with Kawi style billet couplers, like me, alignment is crucial.

 

[njfl]

There was a thead the other day about B pipe rubbing the side of the hull. Before mine broke through, I had noticed a vibration. It was due to the B pipe chamber hitting the side of the hull and shaking the entire boat. Take a look and see if this is a possibility.

 

[chunky]

The engine mounts i had fitted are monkey grip.
I will try the engine alignment first then and see how it goes, although i didnt realise that they made the ski vibrate until they got broke in.
Maybe this could be (part) of the problem.

 

[chunky]

Have noticed that the two faces of my coupler are tight together yet another ski a year old the two faces have a gap between them!
Should there be a gap and if so what should it be, and would the two faces meeting cause vibration??

 

[Kny21]

Have noticed that the two faces of my coupler are tight together yet another ski a year old the two faces have a gap between them!
Should there be a gap and if so what should it be, and would the two faces meeting cause vibration??

If they are touching your motor needs to come forward.... the spec if I recall is something like 2mm spacing or the thickness of a quarter.

 

[sjetrider]

Have noticed that the two faces of my coupler are tight together yet another ski a year old the two faces have a gap between them!
Should there be a gap and if so what should it be, and would the two faces meeting cause vibration??

yes there should be aprox .187" gap and yes this will cause vibration and eventually CARNAGE. Loosen motor mounts and move motor forward and also check for propper allignment w/ a straight edge before retightening. EASY FIX assuming no carnage yet.

 

[chunky]

Got it