Where is this vibration coming from??? PROBLEM FIXED

[oxnard111]

So I am almost done getting my ski back together. All I have left is to install the ride plate and run some primer line. I fired her up for the first time and when I rev the engine I hear a really loud vibration. To me it sounds like the chamber is hitting something, but I can't tell. It may be rubbing on the hull since my re enforcement, but I don't think it is. It also sounds more like a metal on metal sound if that makes any sense.

The only difference to the engine setup since my previous install is I have added Kenny Keepers, re enforcement to the sides, and am now using a factory pipe coupler between the chamber and the water box.

I have heard this same noise before on other people's superjets so one of you out there must have come across this before. But never mine. Share your experiences and what you did to solve this problem.

Do you think that the chamber is too close to the head pipe, and the two surfaces are rubbing?

 

[Big Kahuna]

most likely the camber it hitting the bed plate. you may can fix this by just rotating the chamber.

 

[demolition_x]

or lifting up the water box with some turf or something.

 

[oxnard111]

it is neither of those. I have already have a thick layer of turf under the waterbox. I can almost fit my finger between the bed plate and the chamber. I spent like .5 hours just getting the correct rotation on the chamber. I have already dented my chamber to get it to clear. I can also stick a 1/8" piece of cardboard between the chamber and the side of the ski and it slides right through.

 

[demolition_x]

the the alignment on the coupler good?

maybe you left a bolt you left loose and something like the FA is chattering a bit?

do the kenny keepers touch the bead plates?

jst keep going through the whole motor compartment and you will find it.

 

[oxnard111]

the the alignment on the coupler good?

maybe you left a bolt you left loose and something like the FA is chattering a bit?

do the kenny keepers touch the bead plates?

jst keep going through the whole motor compartment and you will find it.

a loose bolt is a possibility, but I don't think so.

The keepers are not touching the bead plate.

seems like my alignment of the coupler is good, but i could be wrong. I just got my chamber ceramic coated, and the inside of the hull is re enforced with carbon, so I think I'll go take it for a ride, let it rub a little more, then pull the chamber and see where it is rubbing. Between the shininess of the chamber and carbon, I should see where it is coming from.

 

[ANT]

Did you install kenney keepers. If you did it is those, it doesnt seem like they are touching the motor but they are underneath they always touch there. Only thing you can do is grind them down or let them where in. If your b-pipe is rubbing the hull it wont make a noise like your talking about, but regardless take off your chamber and put a piece of turf on the chamber so it won't rub the hull, if you don't you'll eventually wear through the weld on the chamber and it will leak.

If you don't have Kenney Keepers, then your crank needs some new upper and lower bearings bad if you already didnt rebuild it.

 

[cambo au]

You Did The Jss Stator While It Was Apart Right?
Did You Put The Spring And Washer In The Front Cover For The Bendix ? That Will Also Make A Similar Noise I Know From Experience

 

[link]

Check the bolts on the keepers, I have had to trim a few as they bottom out on some skis, rattle like crazy.....

Have done 10+ sets & its happened on 3 of them...

 

[kevbo]

Throttle cable rubbing the hull?

 

[oxnard111]

Rode the ski with the vibration today. New tubbies felt great. Vibration/tinging was defiantly audible with the hood on while riding.

Just wondering but has anybody experienced breaking that single baffle on the inside of the chamber? Maybe it broke a little loose while dent the chamber??? :dunno: Just wondering if that seems plausible?

 

[oxnard111]

I'm going to check all your suggestions. I'll keep you updated.

When asked earlier if the keepers touch the bed plates, I only know that they are not touching between the keeper and the front of the plate, but underneath I cannot say.

 

[ANT]

I'm going to check all your suggestions. I'll keep you updated.

When asked earlier if the keepers touch the bed plates, I only know that they are not touching between the keeper and the front of the plate, but underneath I cannot say.

if you didnt check underneath then thats probably where your noise is coming from. if you want it to stop your gonna have to grind where it protrudes in front of the motor mount underneath the motor. If you don't feel like unbolting your motor and all you can just leave it, it won't hurt anything. A lot of people leave it and it just wears in over time. If you leave it, the small spot where it rubs underneath the bedplate will rub in maybe only 1/16" into the bed plate in that one spot then you wont hear it anymore. Really you will have no issues if you leave the Keepers alone.

 

[oxnard111]

You Did The Jss Stator While It Was Apart Right?
Did You Put The Spring And Washer In The Front Cover For The Bendix ? That Will Also Make A Similar Noise I Know From Experience

Finally fixed the problem. I had pulled the engine to check the keepers, no rubbing. Ground down the bed plate a little more for good measure, no help. Re shimmed my engine, no help. Added hydro turf between hull and pipe, no help.

Then finally the other night while working on another ski I had an epiphany. I put the large washer on the wrong side of the bendix!

Pulled the tank, flywheel cover, and flywheel, switch the washer, and what do you know? Once I put it back together the vibration is completely gone...

But some of the teeth on the flywheel are a little chewed up... So I might be looking for a good condition 61x flywheel I can send out to get lightened.

 

[Motorheads5]

that's interesting because I noticed on a 701 it had a spring in the housing cover side for the benbix gear and then a week later I was into my 650 kawi and there was not a spring in there so I looked it up on a part's breakdown and on the kawi diagram for that year of engine it did not show a spring . you sure see alot of bendix needed post's I wonder if I should tear apart my kawi and put a spring in there to preload the bendix. that's a drag to lunch a flywheel because of a small spring.

 

[Idok]

bendix issues can be tricky and VERY costly....glad you got her figured out!