Shims - Can they fall out? -UPDATE

[Team Bristow]

While on the lake this weekend we cruised a weedy channel, after leaving and hitting the big lake we powered up and immediately cavitated. I assumed that we pulled in weeds and cleared all that I could reach but it did not stop the cavitation. We limped back to the launch and took the boat in to our marina back home.

Well the marina called today to tell me that they pulled the pump and didn't find anything. They lake tested it and still cavitated. The brought it back and pulled it apart again only to find that it was missing a shim.

So, can a shim fall out?

 

[Lspeedss]

Shim? Ok I'm stumped.

 

[Lspeedss]

By shims are they talking wear rings?
Perplexed..

 

[Team Bristow]

I asked where and what when they called and the guy was unable to answer. I am starting to think I am getting charged for blinker fluid.

I think I will give them a call in the morning.

 

[Cobra Jet Steering LLC]

I have no idea what SHIM they could possibly be talking about.
You had weeds and there was probably something between the impeller blades causing cavitation, it's the nature of the beast. This time of year we get loaded with huge amounts of sea grass in our area so I assume it is probably bad in most places.
Learn not to use reverse in real shallow water as that kicks up trash into the intake grate.
Also do the reverse move if you feel weeds in the pump.
Get going in reverse in water that is over 4 feet deep.
Turn off the engines this stops the suction , quickly place the controls in forward to open the gates.
While you drift backward the water will wash out the weeds through the intake grate.

 

[Bruce]

I am not aware of any shims anywhere in any Yamaha jet.

 

[Murf'n'surf]

This is strange! Please go to this dealer and ask for them to show you what part they are referring to, then come back here and fill us in. As far as I know, there is no part on our boats that can fall off under normal usage.

Sounds like they lost a part.

 

[Speedling]

I have shims. Well, more like wedges. And they are certainly not stock items, lol

 

[JC6275]

I am taking a shot in the dark here, so if I'm way off I apologize in advance. Are there any alignment shims to align the shaft with the Motor??

 

[Murf'n'surf]

I am taking a shot in the dark here, so if I'm way off I apologize in advance. Are there any alignment shims to align the shaft with the Motor??

Yes there can be. There are also shims around the intermediate bearing assembly where it mounts to the wall.
Losing one shouldn't cause cavitation.

 

[Gym]

I believe what they may be referring to is a motor mount spacer also referred to as a shim. It's # 9 on this site. http://www.yamahasportsplaza.com/oemparts/a/yam/5004ec46f8700223a0a06bbb/engine-mount The spacer would keep the motor lined up with the output shaft going to the pump. I'm guessing you would get more vibration than cavitation without the spacer but if it threw the impeller shaft out of alignment you would probably get cavitation also.

 

[JC6275]

@Gym I was thinking about a motor mount shim as well, but I would hope the shop would have seen it missing.. it should be laying in the engine compartment. I suppose it could be hidden under a motor out if site. From the description I'm betting on a shaft shim or a motor mount alignment shims..

 

[Ronnie]

I'll go out on a limb by stating that it sounds like the marina is bullshitting you. My "guess" is that the cavitation is the result of vegetation you sucked up taking off some of the silicon that is used to seal the pump. Do you experience cavitation throughout the throttle range or just when you move from idle to WOT quickly?

 

[Lspeedss]

I'll go out on a limb by stating that it sounds like the marina is bullshitting you. My "guess" is that the cavitation is the result of vegetation you sucked up taking off some of the silicon that is used to seal the pump. Do you experience cavitation throughout the throttle range or just when you move from idle to WOT quickly?

I agree..maybe even a little piece of debris stuck in the impeller. They can be sneaky.

 

[Team Bristow]

Turns out shim = washer and said washer did not fall out but was not installed. The marina refuses to believe that they could have forgotten to install it although they are the only people to touch the pump. Every time that I asked them how this could happen they say "you took it to someone else for service and they forgot to install the washer". I of course reply with "only you have touched the boat" to which they answer "can't be true because we would not have made that mistake". They keep pointing out that there is blue locktite in spots and they don't use blue so I am obviously not telling the whole story.

Oh well, a $352 washer later and the boat is back in the driveway ready for tomorrow's three day trip up north.

Cheers!

JB

 

[JC6275]

WTH!!! that sucks I can't believe places who do shady stuff like this stay in business..

 

[Bruce]

Glad you are back on the water!