The end of loose bolts

[Waternut]

I've got a fantastic ability to rattle bolts out of my exhaust pipes. I did helicoils on my 750 and still rattled the bolts out and eventually went to studs and nuts with JB weld on the threads after rattling the studs loose as well. I just helicoiled the threads on my SJ as well and decided to borrow a concept from aviations safety critical bolts...safety wire!

Well obviously I'm not paying the money for aviation bolts with predrilled holes so I bought a pack of 1/16" drill bits and some safety wire and started drilling. I drilled the first bolt successfully with one bit. 9 drill bits later and 3 wasted bolts with drill bit stuck in them, I finally got my second bolt drilled successfully. I'm out of drill bits for the 3rd bolt. I also tried to tie the bolts together but due to the complicated position, gave up and eventually just tied them into something else.

 

[ski4]

i don't understand why you are having such a problem . there has to be some underlying vibration issue or something.


i mean i have had intermittent loosening ( and even a chronic problem on my old hx) none needed extreme measures like you are discussing

usually a good engine alignment, proper torque and a generous supply of loctite solved each and every issue

 

[Idok]

i don't understand why you are having such a problem . there has to be some underlying vibration issue or something.


i mean i have had intermittent loosening ( and even a chronic problem on my old hx) none needed extreme measures like you are discussing

usually a good engine alignment, proper torque and a generous supply of loctite solved each and every issue

yeah no kidding!!!!

 

[Shonuff]

God Yamahas are some vibratin' sonsabitches.

 

[Idok]

God Yamahas are some vibratin' sonsabitches.

only if they're improperly setup........


broken mounts or too low an idle could both increase vibration.....I'd check the driveline as well..

have NEVER seen anyone ever have to safety wire anything outside of PV assemblies...

 

[ski4]

God Yamahas are some vibratin' sonsabitches.

nuthin compared to a sea doo hx and the dual drive shaft evil mess they were

lol thank god that was under warranty
if i would have had to fix that on my own i would have blown it up

thousands in parts and labor im sure . but they eventually figured it out ( after a summer of lost water time)

 

[Waternut]

Want to clarify something... The vibration issues have happened on two ski's. One 750 and one SJ and the 750 doesn't get aligned.

 

[ski4]

Want to clarify something... The vibration issues have happened on two ski's. One 750 and one SJ and the 750 doesn't get aligned.

doesn't matter
there is still something unusually wrong
there is too many fully modded 750's that don't have your problem

something isn't right, maybe it's not a harmonic vibration issue , maybe it is.
but there is something unique to how you are doing something that is causing you to have this chronic problem if not vibration on two skis

of course bad luck must also be ruled out

 

[McDog]

Bad luck you have in abundance....on both skis.

 

[SuperJETT]

Bolts/nuts loosening up like that is sometimes an indiction of detonation--it causes high frequency vibrations that will loosen/break anything over time. Motor vibration doesn't typically cause that.

 

[Waternut]

there is something unique to how you are doing something that is causing you to have this chronic problem if not vibration on two skis

I've always contributed it to riding style. I've noticed that right off idle is the most vibration intensive rpm area and that's unfortunately where I like to be just before hitting a small to medium sized wake. So most of the day is spent in that horrible vibration or landing jumps.

 

[ski4]

I've always contributed it to riding style. I've noticed that right off idle is the most vibration intensive rpm area and that's unfortunately where I like to be just before hitting a small to medium sized wake. So most of the day is spent in that horrible vibration or landing jumps.

Hmmm. I don't think your riding style is as unique as your problem though. I'd be suspicious

 

[Idok]

I've always contributed it to riding style. I've noticed that right off idle is the most vibration intensive rpm area and that's unfortunately where I like to be just before hitting a small to medium sized wake. So most of the day is spent in that horrible vibration or landing jumps.

its not your riding style, there is a mechanical issue no doubt.....


unless its something silly like assembling the pipe with a 1/4" ratchet and your getting enough torque on the bolts..

 

[WFO Speedracer]

There is a certain rpm on any given engine where the engine harmonics are God awful,you can move the rpm around with impeller pitch somewhat but you can never make it go away completely.On Seadoos that continually break exhaust bolts they told us to change the impeller pitch slightly to get it out of that range of rpm,usually 500 rpm or so will do the trick,I am not saying that is your problem here just giving you something to think about.

 

[Waternut]

unless its something silly like assembling the pipe with a 1/4" ratchet and your getting enough torque on the bolts..

No I torque them down properly initially. Then after the helicoils, I'll over torque them to 35-40ft lbs since the threads can withstand it.

I'm certainly not recommending everyone use safety wire on their bolts but maybe if you've tried all the common fixes and the problem still exists, this might be a solution. I'm just not willing to start paying big money and guessing what could be really causing the problem. Hopefully this works.

 

[sxi4evr]

im having the same prob. i just rattled loose my 7/16-20 socket head cap srews. :banghead:

 

[Waternut]

im having the same prob. i just rattled loose my 7/16-20 socket head cap srews. :banghead:

Sucks doesn't it?! Spend all that time and money putting helicoils in place and you're now worse off than before because you've got 3 huge holes in the manifold.

 

[ski4]

No I torque them down properly initially. Then after the helicoils, I'll over torque them to 35-40ft lbs since the threads can withstand it.
.

why would you do that? especially 30-40 lbs over?


speedracer has a point about certian places on a throttle that will make the motor run rough. but to have that problem on two brands of skis???????

you've go something going on there and wiring stuff in place is only a band aid for your problem more than likely

much luck man, i hope it works out or you

 

[SUPERTUNE]

Use 1211 on the shanks of the bolts to kill the vibration, torque to 42-45 ft-lbs. If your theads won't hold 42-45 ft-lbs, there's your problem too.
MUST use a quality ultimate green gasket! Never a home made gasket without a metal core.
Edit: Can also use like a all metal gasket like the OEM Kawasaki gaskets.

 

[Waternut]

why would you do that? especially 30-40 lbs over?

It's actually just 35-40...not 35-40 over normal.

Use 1211 on the shanks of the bolts to kill the vibration

I never thought of that. I've used a bunch of stuff but all of it cured hard. If the safety wire ever breaks, I'll give that a shot.