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Port side pump issue

Chip F.

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First a little history.. last fall both my pumps were pulled by the dealer in order to repair several gel coat cracks around the mounting bolts of both along with gel coat cracks at my rudder attachments.

Tonight I took the boat out for testing and discovered severe cavitation on the port side as I increased the throttle to it and then the RPMs pegged. If I babied the throttle I was able to get the boat up on plane . I checked the clean out plugs and reseated both but I know that both were seated properly.

I came home and looked at a couple threads on the issue and what I’ve concluded is that the impeller clearance by eyeball looks tight but I did not put a feeler gauge in there. It looks like the tunnel has gaps and that’s what I think the issue is. Looking for experienced opinions. Here are some photos:
186DC5F5-FFCF-4DF4-83A8-445DDC4171A9.jpeg
 
Last edited:

Scottintexas

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if you could edit your photo and circle where you think the gaps are, I'm sorry I'm having a hard time seeing them,

What exactly did the dealer remove, nozzles/impeller or intake grates or transom plate?

My cavitation was caused by loose/missing silicone in the intake grate/tunnel area, we also had another member that had to remove his transom plate twice to correct an air intrusion, if I remember correctly,
 

Chip F.

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It looks like everything was removed by looking at all the new sealant
 

Scottintexas

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swatski

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Looks like your impeller is fine, it must be the missing sealant - sounds like you are sucking air out of control!

I would pull the pumps and port/blueprint/seal the tunnels.

--
 

Ronnie

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I think that you should smooth that transition out with 3m 4200 or 5200, a razor blade and some painters tape. Also find someone else to work on your boat. Imho your dealer caused the problem or more of one.
 

Chip F.

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I'll pull the pump and check things out and smooth it out. The dealer is almost 3 hrs away. Is the 4200 preferred over the 5200? The boat ran fine prior to the dealer pulling the pumps for the crack repairs. Does anyone know what the black sealant might be that is on there now? Thanks for the input and help.
 

Chip F.

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Well I tried to pull it but there is this black gasket material between the pump housing and wear ring and then between the wear ring ang transom plate nothing will budge...
I found the work order for it and it is black 5200.
Should there even be sealent between these?
I thought wasit 4 bolts and pull.


95315CA1-2CF2-4CDF-8B81-C68ACACF7621.jpeg
DA7667B3-492D-4CF7-A14F-C7BFB4C5B293.jpeg
 
Last edited:

Sbrown

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I found the work order for it and it is black 5200.
Should there even be sealent between these?
At least you found out where the missing sealant went.......
 

Chip F.

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Yea it's everywhere they even used my trailer to wipe their fingers off!
 

bronze_10

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Uhhhh,, they put the pumps back together with 5200?!? !??! That's a 1 hour drive to a the dealer that's 3 hours away and show my ass when I get there problem!
 

bronze_10

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Someone told the mechanics to make sure the pumps are sealed and the idiot sealed the actual pump assembly with 5200 instead of the tunnel...
 

Cobra Jet Steering LLC

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You may want to send all this info to Yamaha including the finger prints on the trailer.
 
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