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Help me out, my new 115 Yamaha rides with the Cavitation Plate below the water line when the boat is up on plane. It doesnt' matter how the motor is trimmed. I say it should ride just a hair above the water line and that the Dealer should fix it. Am I out of my head or am I right?
The cavitation plate must be in the water. If it is out of the water...your prop will possibly break the surface and my boat has a water pickup in the bottom of the cavitation plate and would suck air if out.
your cavitation plate should be right at the water level. As a rule of thumb it should be 1 inch above the hull for every 12 inches back. (if you have a eurotransom, or bracket or something.)
If your cavitation plate is under water you might get better performance if you raise the motor. Having said that, I don't know if the dealer is responsible for that. Dealers do not nessesarily set the boat up at optimal performance. The motor is where they put it, and the prop you get is what they put on it. Most of the time, you can improve the performance on your boat with a different prop, and setting the engine height correctly.
Ken2 has it right: 1 - 1.5 above the lowest part of the keel for the cavitation plate. Manufacturers, from what I understand, put the motor on the lowest setting for simplicity, not optimal performance. It is up to the owners to do the rest.
__________________ Hubs Tub
Scout 162 w/90 Yammie
Johns Island, SC USA
jethro1 - 6/1/2006 9:05 AMI have never seen or heard of a cavitation plate being installed on a Yamaha, or any outboard motor for that matter.Sorry, can't help you.
Agreed...I've heard of "anti-ventilation" plates, but not anti-cavitation plates. Lots of very experienced boaters mangle the concepts, so it seems to be a common problem.
Yamaha specifically names the Anti-[take your pick: Cavitation/Ventilation] plate an "Anti-Cavitation Plate" on Page 11 of the F115 owners manual (viewable on-line if you want to verify.)
As jyasaki stated. Look under "basic components" of an outboard on yamaha's owners manual.
Yamaha calls it an anti-cavitation plate.
Its not something you install on a motor. Its the flat plate just above the prop.
there is a pretty good chance your motor may have one too.
Or maybe you guys are right and Yamaha does'nt know what their talking about.
Either way, great post. very informative.
I expecially like the one that says "never heard of it, sorry can't help you"
we need more informative post like that on this site.
jethro1 - 6/1/2006 9:05 AMI have never seen or heard of a cavitation plate being installed on a Yamaha, or any outboard motor for that matter.Sorry, can't help you.
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Agreed...I've heard of "anti-ventilation" plates, but not anti-cavitation plates.* Lots of very experienced boaters mangle the concepts, so it seems to be a common problem.
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I bet these guys BOTH use knots rather than statute miles per hour...and if you tell them to turn "left" instead of to port, they'll pretend not to understand!
Well, I was being a bit flippant but was also trying to make a point. To get the best possible answer the question has to be presented as accurately as possible. It has been reported on The Hull Truth now many times that it is an anti-ventilation plate, not an anti-cavitaion plate. Better to just say "the flat plate above my propeller" than to use an incorrect term and keep perpuating this common error.
I can understand the Japanese calling this an anti-cavitation plate because of translation errors. However, just cause someone with some authority says it does not make it so. Heck, GW and D. Rumsfield told us all about weapons of mass destruction being in Iraq but guess what?
Oh, even though I am ex Navy I use statute miles. Also, left, right, front, back, bathroom, etc, etc.
Going back to my afternoon nap now. ZZZZZZZZZZZZZ.
Yamaha probably calls it an anti-cavitation plate because if they called it an anti-ventilation plate 90% of the people wouldn't know what it meant.
The plate helps prevent ventilation and has nothing at all to do with cavitation.
I realize the fact the the plate has nothing to do with cavitation, and its proper term should be ventilation plate.
I posted the yamaha site to show that they call it a cavitation plate. Its not just a "new boater" that confuses the term, apparently its the people that build the damn engine as well.
BUT, Those guys know what the original poster meant.
If your not going to help the guy out, why bother posting a reply?
And then throwing in political S#%T on top of a worthless F&%K$%G post!
I love it, not only do you not give any info to the guy, you stick your nose up and say "I don't know what your talking about" cause you think he used the wrong term.
If Yamaha calls it a Anti-Cavitation plate and he owns a Yamaha then he was 100% correct in calling it an Anti-Cavitation plate. If you owned a Yamaha and you needed to order the CORRECT part you would have to request an Anti-Cavitation plate.
Even if the name is a misnomer it is still the name.
The purpose of the plate (call it what you want - doesn't really matter) is to make it more difficult for air to get to the prop from the surface of the water. To that end, the plate has to ride, at the very least, at the surface of the water.
There are, IMO, more critical aspects determining how high the motor should be mounted: prop depth below the keel, prop running depth, etc. Plate depth is not really an indication of proper engine mounting height.
Anti- Ventalation Plate Cavitation plate whatever. Stop being so technical. The Plate that is just above the Prop.
From the way I see it if the motor is trimed up and that plate is running below the water line it is helping to force the bow up.
I get all the stuff about getting the details correct but next time just shoot me for making a mistake. I always though boaters would lend a helping hand to another boater in need.
I know i've offered my time, gas, radio and cell phone to guys in need any number of times.
Next thing I know some one will be correcting my grammer and not answering questions becouse i didnt' spell the words right.
Thanks to everyone, the constructive critisisim helped. The opinions and facts helped more!
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