Cracked Cavitation Plate - What to do?

kyudizky

Seaman
Joined
Aug 3, 2009
Messages
70
While wiping the boat down after trailering it the last time out, I noticed a crack in my cavitation plate. I'm almost certain I didn't hit anyting in the water. Could I have caused this? Can it be repaired/welded without replacing the lower unit houseing? Can I just JB weld it? I really want to go fishing in it this weekend, but should I not run the boat till I get this fixed?

I looks like the rear left corner of the plate was repaired in a similiar fashion by the previous owner.

The motor is a '98 225 EFI.
Please see picture of the crack

Thanks for the help!
 

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j_martin

Admiral
Joined
Sep 22, 2006
Messages
7,474
Re: Cracked Cavitation Plate - What to do?

While wiping the boat down after trailering it the last time out, I noticed a crack in my cavitation plate. I'm almost certain I didn't hit anyting in the water. Could I have caused this? Can it be repaired/welded without replacing the lower unit houseing? Can I just JB weld it? I really want to go fishing in it this weekend, but should I not run the boat till I get this fixed?

I looks like the rear left corner of the plate was repaired in a similiar fashion by the previous owner.

The motor is a '98 225 EFI.
Please see picture of the crack

Thanks for the help!

It can be welded.

What chewed up the corner of it, a muskrat?
 

westexasrepublic

Chief Petty Officer
Joined
Jun 17, 2009
Messages
524
Re: Cracked Cavitation Plate - What to do?

actually it looks like the rear corner of the plate has damage that is consistent of someone smashing it from a force above and simultaneously causing a crack at the point of stress.... ie backed in under something or something heavy falling on that left corner is what it looks like.
 

kyudizky

Seaman
Joined
Aug 3, 2009
Messages
70
Re: Cracked Cavitation Plate - What to do?

W. TX - I had similiar thoughts about the crack. I bought the boat a month ago, and new the corner repair was there, but just saw the crack this past time out, and I've had it in the water fishing the past 4 weekends, so I don't know if I just haven't seen it or what. I go over the boat thoroughly after each use so I hate to believe I over looked it each time and when I bought it, maybe I did though???

But It can be repaired??? Would some JB weld on top suffice or would it be wise to take it to a shop?
 

j_martin

Admiral
Joined
Sep 22, 2006
Messages
7,474
Re: Cracked Cavitation Plate - What to do?

W. TX - I had similiar thoughts about the crack. I bought the boat a month ago, and new the corner repair was there, but just saw the crack this past time out, and I've had it in the water fishing the past 4 weekends, so I don't know if I just haven't seen it or what. I go over the boat thoroughly after each use so I hate to believe I over looked it each time and when I bought it, maybe I did though???

But It can be repaired??? Would some JB weld on top suffice or would it be wise to take it to a shop?

That's 225 wild horses. It needs to be properly welded for safety. If it were the skeg, I'd say replace the LU housing.

A good prop shop can do it right on the boat. Leave the LU lube in for cooling, and replace it after the repair.

hope it helps
John
 

Chris1956

Supreme Mariner
Joined
Mar 25, 2004
Messages
28,093
Re: Cracked Cavitation Plate - What to do?

How close is the prop to the A-V plate. Is it possible the prop hit it, or something got between the prop and the A-V plate and the force of the prop turning caused it to crack??
 

daveswaves

Ensign
Joined
Mar 22, 2002
Messages
901
Re: Cracked Cavitation Plate - What to do?

That type of crack can happen when a rather large fishing buddy stands on the Anti ventilation plate to reach something in the boat.
 

robert graham

Admiral
Joined
Apr 16, 2009
Messages
6,908
Re: Cracked Cavitation Plate - What to do?

A good welder can run you a bead right down that crack, no problem...
 

kyudizky

Seaman
Joined
Aug 3, 2009
Messages
70
Re: Cracked Cavitation Plate - What to do?

Daveswaves, sounds like you are speaking from experience. If that happened to me, after i got done slapping him silly, he (she) would no longer be my fishing buddy!

I called a local shop here in Macon, GA. He quoted me 350 if he has to take the gear case off and 150 if he doesn't have to. Gonna idle and troll only, to my fishing spots Saturday morning (i HAVE to go fishing) then take it to him to get it fixed.

Appreciate everyones help and input, ya'll are awesome!!!
 

j_martin

Admiral
Joined
Sep 22, 2006
Messages
7,474
Re: Cracked Cavitation Plate - What to do?

Daveswaves, sounds like you are speaking from experience. If that happened to me, after i got done slapping him silly, he (she) would no longer be my fishing buddy!

I called a local shop here in Macon, GA. He quoted me 350 if he has to take the gear case off and 150 if he doesn't have to. Gonna idle and troll only, to my fishing spots Saturday morning (i HAVE to go fishing) then take it to him to get it fixed.

Appreciate everyones help and input, ya'll are awesome!!!

Ask him if he wants you to take the LU off and bring it to him. It's about a 30 minute job the first time. Ten minutes after that. Takes about 15 minutes to put it back on with a light duty helper. (significant other?)

It'll also give you a chance to check out the water pump.

BTW, if that piece flops off while you're messing around, it could get more expensive.

hope it helps
John
 

Mi duckdown

Commander
Joined
Apr 14, 2007
Messages
2,575
Re: Cracked Cavitation Plate - What to do?

J martin seems A little crusty. be He is right. Time for a water pump, Cheap prevenative SP? maintenance. Lost my spell check.
150. seems a little high unless he is Going to Guarantee no loss of seals.
Which won't happen any way.??
 

kyudizky

Seaman
Joined
Aug 3, 2009
Messages
70
Re: Cracked Cavitation Plate - What to do?

I think I'm going to get into the huge expensive manual i bought and look into taking the LU off as suggested.

Another stupid question, is the foot oil completely contained in the LU, so if I take it off, will I have to replace it?

J martin -- "Leave the LU lube in for cooling, and replace it after the repair." welding the cav plate will heat up the rest of the LU that much???
 

robert graham

Admiral
Joined
Apr 16, 2009
Messages
6,908
Re: Cracked Cavitation Plate - What to do?

Just get it welded, no need to remove the foot. If you're worried about heat maybe lower foot into a bucket of water while it's being welded...no big deal.
 

j_martin

Admiral
Joined
Sep 22, 2006
Messages
7,474
Re: Cracked Cavitation Plate - What to do?

To answer the questions. The foot completely contains the oil. There's not even a gasket between the foot and the midsection. It weighs about 30 lbs without the prop.

If the foot is off, the welder can rotate it and get perfect position on both sides of the weld. It can be done out of position, but it is more difficult and the weld may not be as good.

They go at it a bit at a time. Lube in the LU will prevent local hot spots that could bend things or wreck a seal. The lube may or may not be scorched in the process. Just change it and be sure it's good. That's probably easiest after you hang it back on the motor.

Before you drop the foot, loosen up the lower (drain and fill) plug on the LU and get a drop or 2 of the fluid to look at. If it's clear or black fluid, yer OK. If it's water or milky oil, you might as well get the seals serviced after the welding is done.

When you put the foot back on, pay close attention to the details in the manual, such as lubing the driveshaft, gear position, etc.

hope it helps
john
 

bobjoe1

Petty Officer 3rd Class
Joined
Dec 29, 2009
Messages
87
Re: Cracked Cavitation Plate - What to do?

Just last week had same thing happen and had no clue why. I have a trolling plate on and sometimes I have backed into the garage wall. Oh well. Anyway, the housing is aluminum and has to be helearked welded. I had a friend which is a good welder do mine. I did not drain anything but did change the oil aftewards since it needed it. No need to pull anything apart. Works great
 

sschefer

Rear Admiral
Joined
Nov 13, 2008
Messages
4,530
Re: Cracked Cavitation Plate - What to do?

See that little round spot dead center of the plate. I bet that was a hole for a whale tale. And yes, with that much HP you can easily crack the plate with a whale tale. That's why I hate to see people run them. Smart tabs are a much better solution.
 

kyudizky

Seaman
Joined
Aug 3, 2009
Messages
70
Re: Cracked Cavitation Plate - What to do?

it kinda does look like a whole but its not, when i read that i ran out of the house and looked at it second guessing myself though. So, no whale tail. Who knows what caused it...Going to take it on Saturday to get it fixed regardless. I'll post a pic of the repair on Monday!

By chance as anyone from around middle Geargia and used a shop named Boatworks before. Thats were I'm taking it, just curious as to anyone elses experiences with them.

Thanks for the help everyone!
 
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