Knocking noise at idle??

[Rampage]

I have the strangest knocking noise when the ski is at idle. I cant tell if its somthing vibrating in the hull or the motor. It goes away if I increase the RPM's at all. Even 2 or 300 more RPMs and its gone. Any ideas? I think if I had a bad bearing or somthing it would be worse at higher RPM's right?? I cheack all the motor mounts, and exhaust...and I just cant seem to find it.

 

[Dr Honda]

it's a normal "SeaDoo" knock. When the pump doesn't have enough pressure in it... it will shift back and forth on it's thrust bearing.

If it goes away, in the water, and just off of idle... don't worry.

 

[Rampage]

Doc, this is more in the hull area. I know the noise you are referring to. I can hear it at idle in the water, but def goes away with any throttle increase. Its bugging the crap out of me. If your water box was banging on the inside of your hull...that is what it sounds like.

 

[Dr Honda]

Since I don't have my head in your hull listening... I can't say for sure... but the pump knock will resonate up into that big hollow hull, and it will sound like it's right under your butt.


BUT... you could check for loose, or missing straps on the battery, and water box. Also, make sure all the bolts are in the exhaust, and tight.


Oh... one other thing... check for a busted motor mount, or missing bolts from the mounts. Grab the engine, and push it side to side. If you have a bad mount... you will feel it.

 

[Rampage]

Thanks!! Motor mounts are good and tight. I didnt see any loose straps or anything. But in your opinion you dont think this is somthing inside the motor?
Thanks for the help :cheers:

 

[Dr Honda]

Well.........


most of the time... and internal knock will get louder as you put a load on it. Also, if you don't have the knock out of the water... it's normally the pump.


But... If you want to rule it out for sure... take the pump, and drive shaft out, and start the engine. There are a very few, rare instances of the counter weight getting out of time, and ejecting thought the side of the engine. (in the 800 engines)

 

[Rampage]

once Im off idle it purrs nice!! Im hoping its just a rattle in the exhaust I am missing

 

[Dr Honda]

once Im off idle it purrs nice!! Im hoping its just a rattle in the exhaust I am missing

I'm sure it is.

 

[mikemopar]

Same knocking problem

With our '96 Gti it sounds like the same idle knock problem we've been experiencing since last year. At an idle it sounds like something is vibrating badly and resonating through the hull. We are original owners and can't seem to bear down on where it is coming from. It has about 200 hrs. on it. The engine mounts are in tact and tight. Is there anything else we should be looking for?

 

[LouDoo]

SeaDoo Rattle

There is a kit available for this problem, it consists of a new cone, a stainless spring and a teflon washer. It puts pressure on the drive shaft, not allowing it to move as much. The kit works moderately well, you will still have the knock but not as bad. I think this is standard in newer doos.

You might want to try, it's not real expensive, I think around $ 25.00.

Lou

 

[Rampage]

With our '96 Gti it sounds like the same idle knock problem we've been experiencing since last year. At an idle it sounds like something is vibrating badly and resonating through the hull. We are original owners and can't seem to bear down on where it is coming from. It has about 200 hrs. on it. The engine mounts are in tact and tight. Is there anything else we should be looking for?

I had a 97 gti with a knock almost like what I have now...and on that I found at the corner back side of the water box(around the area where the black exhaust hose comes out)...the corner was knocking or vibrating against the hull...I got a thick piece of rubber and pulled the water box hard to the opposite side and stuffed it in there. Now that worked for awhile but eventually it would vibrate back out. So then I got the thick rubber exhaust band from my GTX parts ski and wrapped it around just where the corner was vibrating. Not sure if this helps

There is a kit available for this problem, it consists of a new cone, a stainless spring and a teflon washer. It puts pressure on the drive shaft, not allowing it to move as much. The kit works moderately well, you will still have the knock but not as bad. I think this is standard in newer doos.

You might want to try, it's not real expensive, I think around $ 25.00.

Lou

Lou I think you are still talking about the pump noise when out of the water.

 

[LouDoo]

I had a 97 gti with a knock almost like what I have now...and on that I found at the corner back side of the water box(around the area where the black exhaust hose comes out)...the corner was knocking or vibrating against the hull...I got a thick piece of rubber and pulled the water box hard to the opposite side and stuffed it in there. Now that worked for awhile but eventually it would vibrate back out. So then I got the thick rubber exhaust band from my GTX parts ski and wrapped it around just where the corner was vibrating. Not sure if this helps




Lou I think you are still talking about the pump noise when out of the water.

Actually it's noise from the drive shaft, the spring takes some of the play out of the shaft where it meets the carbon ring.

Lou

 

[Chester]

I have the strangest knocking noise when the ski is at idle. I cant tell if its somthing vibrating in the hull or the motor. It goes away if I increase the RPM's at all. Even 2 or 300 more RPMs and its gone. Any ideas? I think if I had a bad bearing or somthing it would be worse at higher RPM's right?? I cheack all the motor mounts, and exhaust...and I just cant seem to find it.

It's normal when the idle speed is too low. Set your idle to specs and it will go away. As said before, it's the impeller hunting back and forth making a low pitched knock.

Chester

 

[Rampage]

It's normal when the idle speed is too low. Set your idle to specs and it will go away. As said before, it's the impeller hunting back and forth making a low pitched knock.

Chester

Im 1500 in the water and 3000 out of the water.

 

[Rabid]

I have the same noise. Its not coming from the engine compartment but somewhere outside by the nozzle by the sounds of it. the noise isn't bad just intermittent. I thought it was the reverse lid or some slack in the direction nozzle. Thanks for the info guys

 

[Rabid]

There is a kit available for this problem, it consists of a new cone, a stainless spring and a teflon washer. It puts pressure on the drive shaft, not allowing it to move as much. The kit works moderately well, you will still have the knock but not as bad. I think this is standard in newer doos.

You might want to try, it's not real expensive, I think around $ 25.00.

Lou

where can I get it? thanks for the info!!!!!

 

[Rampage]

Update on knock. This has been bugging me like crazy. I know the knock noise from the pump, and the knock I am hearing are 2 different noises. So I took my Raves out and looked down in the Pistons. The front piston looks perfect...the back one, is messed up. Top ring is missing a piece and the edges of the piston on one side is all chewed up. Weird that it still runs so good. Any input. I have a huge ride put together for Saturday and Sunday. Would it be ok to ride if I took it easy. On a side not the second ring down on the piston looks great.

 

[dsw222]

Can you get a pic of it?

 

[Dr Honda]

Update on knock. This has been bugging me like crazy. I know the knock noise from the pump, and the knock I am hearing are 2 different noises. So I took my Raves out and looked down in the Pistons. The front piston looks perfect...the back one, is messed up. Top ring is missing a piece and the edges of the piston on one side is all chewed up. Weird that it still runs so good. Any input. I have a huge ride put together for Saturday and Sunday. Would it be ok to ride if I took it easy. On a side not the second ring down on the piston looks great.

I wouldn't take a chance. If the piston is messed up, and part of the ring is gone... that engine can let go at any moment. If nothing else... I wouldn't want to get stranded.

 

[Rampage]

We are going to be about 200 yards for shore, just playing.... but I dont want to creat lower end problems either. How long does it take to do the top end? If I get the kit today is there any chance of doing it in one evening? I have done pistons on my banshee motor many times, and this looks very simular to that.

 

[Dr Honda]

Yes... it will only take a couple hours to do.

Pop the head off your engine, and figure out what size pistons you need. Also, remove your cyl, and figure out what thickness base gasket you need. Then, Order what you need, and put it back together. (don't forget a gasket kit)

 

[Rampage]

I found a complete kit with Pistons,pins, and all the gaskets needed.